X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/102c1ff4609dbd83066f4e2257307004609403b9..0177044b9f53b8d9d4fa80c5846a62f9d5849e8b:/pcap-linux.c diff --git a/pcap-linux.c b/pcap-linux.c index 8e484beb..61d4db07 100644 --- a/pcap-linux.c +++ b/pcap-linux.c @@ -122,6 +122,7 @@ static const char rcsid[] _U_ = #include #include #include +#include #include #include #include @@ -135,6 +136,12 @@ static const char rcsid[] _U_ = #include #include #include +#include + +#ifdef HAVE_LINUX_NET_TSTAMP_H +#include +#include +#endif /* * Got Wireless Extensions? @@ -156,6 +163,14 @@ static const char rcsid[] _U_ = #include #endif /* HAVE_LIBNL */ +/* + * Got ethtool support? + */ +#ifdef HAVE_LINUX_ETHTOOL_H +#include +#include +#endif /* HAVE_LINUX_ETHTOOL_H */ + #include "pcap-int.h" #include "pcap/sll.h" #include "pcap/vlan.h" @@ -168,6 +183,10 @@ static const char rcsid[] _U_ = #include "pcap-septel.h" #endif /* HAVE_SEPTEL_API */ +#ifdef HAVE_SNF_API +#include "pcap-snf.h" +#endif /* HAVE_SNF_API */ + #ifdef PCAP_SUPPORT_USB #include "pcap-usb-linux.h" #endif @@ -176,6 +195,10 @@ static const char rcsid[] _U_ = #include "pcap-bt-linux.h" #endif +#ifdef PCAP_SUPPORT_CAN +#include "pcap-can-linux.h" +#endif + /* * If PF_PACKET is defined, we can use {SOCK_RAW,SOCK_DGRAM}/PF_PACKET * sockets rather than SOCK_PACKET sockets. @@ -285,7 +308,7 @@ static short int map_packet_type_to_sll_type(short int); static int pcap_activate_linux(pcap_t *); static int activate_old(pcap_t *); static int activate_new(pcap_t *); -static int activate_mmap(pcap_t *); +static int activate_mmap(pcap_t *, int *); static int pcap_can_set_rfmon_linux(pcap_t *); static int pcap_read_linux(pcap_t *, int, pcap_handler, u_char *); static int pcap_read_packet(pcap_t *, pcap_handler, u_char *); @@ -295,17 +318,25 @@ static int pcap_setfilter_linux(pcap_t *, struct bpf_program *); static int pcap_setdirection_linux(pcap_t *, pcap_direction_t); static void pcap_cleanup_linux(pcap_t *); +union thdr { + struct tpacket_hdr *h1; + struct tpacket2_hdr *h2; + void *raw; +}; + #ifdef HAVE_PACKET_RING #define RING_GET_FRAME(h) (((union thdr **)h->buffer)[h->offset]) static void destroy_ring(pcap_t *handle); -static int create_ring(pcap_t *handle); +static int create_ring(pcap_t *handle, int *status); static int prepare_tpacket_socket(pcap_t *handle); static void pcap_cleanup_linux_mmap(pcap_t *); static int pcap_read_linux_mmap(pcap_t *, int, pcap_handler , u_char *); static int pcap_setfilter_linux_mmap(pcap_t *, struct bpf_program *); static int pcap_setnonblock_mmap(pcap_t *p, int nonblock, char *errbuf); static int pcap_getnonblock_mmap(pcap_t *p, char *errbuf); +static void pcap_oneshot_mmap(u_char *user, const struct pcap_pkthdr *h, + const u_char *bytes); #endif /* @@ -313,7 +344,7 @@ static int pcap_getnonblock_mmap(pcap_t *p, char *errbuf); */ #ifdef HAVE_PF_PACKET_SOCKETS static int iface_get_id(int fd, const char *device, char *ebuf); -#endif +#endif /* HAVE_PF_PACKET_SOCKETS */ static int iface_get_mtu(int fd, const char *device, char *ebuf); static int iface_get_arptype(int fd, const char *device, char *ebuf); #ifdef HAVE_PF_PACKET_SOCKETS @@ -324,10 +355,12 @@ static int has_wext(int sock_fd, const char *device, char *ebuf); static int enter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device); #endif /* HAVE_PF_PACKET_SOCKETS */ +static int iface_get_offload(pcap_t *handle); static int iface_bind_old(int fd, const char *device, char *ebuf); #ifdef SO_ATTACH_FILTER -static int fix_program(pcap_t *handle, struct sock_fprog *fcode); +static int fix_program(pcap_t *handle, struct sock_fprog *fcode, + int is_mapped); static int fix_offset(struct bpf_insn *p); static int set_kernel_filter(pcap_t *handle, struct sock_fprog *fcode); static int reset_kernel_filter(pcap_t *handle); @@ -336,7 +369,7 @@ static struct sock_filter total_insn = BPF_STMT(BPF_RET | BPF_K, 0); static struct sock_fprog total_fcode = { 1, &total_insn }; -#endif +#endif /* SO_ATTACH_FILTER */ pcap_t * pcap_create(const char *device, char *ebuf) @@ -361,12 +394,25 @@ pcap_create(const char *device, char *ebuf) } #endif /* HAVE_SEPTEL_API */ +#ifdef HAVE_SNF_API + handle = snf_create(device, ebuf); + if (strstr(device, "snf") || handle != NULL) + return handle; + +#endif /* HAVE_SNF_API */ + #ifdef PCAP_SUPPORT_BT if (strstr(device, "bluetooth")) { return bt_create(device, ebuf); } #endif +#ifdef PCAP_SUPPORT_CAN + if (strstr(device, "can") || strstr(device, "vcan")) { + return can_create(device, ebuf); + } +#endif + #ifdef PCAP_SUPPORT_USB if (strstr(device, "usbmon")) { return usb_create(device, ebuf); @@ -379,94 +425,152 @@ pcap_create(const char *device, char *ebuf) handle->activate_op = pcap_activate_linux; handle->can_set_rfmon_op = pcap_can_set_rfmon_linux; +#if defined(HAVE_LINUX_NET_TSTAMP_H) && defined(PACKET_TIMESTAMP) + /* + * We claim that we support: + * + * software time stamps, with no details about their precision; + * hardware time stamps, synced to the host time; + * hardware time stamps, not synced to the host time. + * + * XXX - we can't ask a device whether it supports + * hardware time stamps, so we just claim all devices do. + */ + handle->tstamp_type_count = 3; + handle->tstamp_type_list = malloc(3 * sizeof(u_int)); + if (handle->tstamp_type_list == NULL) { + free(handle); + return NULL; + } + handle->tstamp_type_list[0] = PCAP_TSTAMP_HOST; + handle->tstamp_type_list[1] = PCAP_TSTAMP_ADAPTER; + handle->tstamp_type_list[2] = PCAP_TSTAMP_ADAPTER_UNSYNCED; +#endif + return handle; } -static int -pcap_can_set_rfmon_linux(pcap_t *handle) -{ #ifdef HAVE_LIBNL - char phydev_path[PATH_MAX+1]; - int ret; -#endif -#ifdef IW_MODE_MONITOR - int sock_fd; - struct iwreq ireq; -#endif - - if (strcmp(handle->opt.source, "any") == 0) { - /* - * Monitor mode makes no sense on the "any" device. - */ - return 0; - } +/* + * If interface {if} is a mac80211 driver, the file + * /sys/class/net/{if}/phy80211 is a symlink to + * /sys/class/ieee80211/{phydev}, for some {phydev}. + * + * On Fedora 9, with a 2.6.26.3-29 kernel, my Zydas stick, at + * least, has a "wmaster0" device and a "wlan0" device; the + * latter is the one with the IP address. Both show up in + * "tcpdump -D" output. Capturing on the wmaster0 device + * captures with 802.11 headers. + * + * airmon-ng searches through /sys/class/net for devices named + * monN, starting with mon0; as soon as one *doesn't* exist, + * it chooses that as the monitor device name. If the "iw" + * command exists, it does "iw dev {if} interface add {monif} + * type monitor", where {monif} is the monitor device. It + * then (sigh) sleeps .1 second, and then configures the + * device up. Otherwise, if /sys/class/ieee80211/{phydev}/add_iface + * is a file, it writes {mondev}, without a newline, to that file, + * and again (sigh) sleeps .1 second, and then iwconfig's that + * device into monitor mode and configures it up. Otherwise, + * you can't do monitor mode. + * + * All these devices are "glued" together by having the + * /sys/class/net/{device}/phy80211 links pointing to the same + * place, so, given a wmaster, wlan, or mon device, you can + * find the other devices by looking for devices with + * the same phy80211 link. + * + * To turn monitor mode off, delete the monitor interface, + * either with "iw dev {monif} interface del" or by sending + * {monif}, with no NL, down /sys/class/ieee80211/{phydev}/remove_iface + * + * Note: if you try to create a monitor device named "monN", and + * there's already a "monN" device, it fails, as least with + * the netlink interface (which is what iw uses), with a return + * value of -ENFILE. (Return values are negative errnos.) We + * could probably use that to find an unused device. + * + * Yes, you can have multiple monitor devices for a given + * physical device. +*/ -#ifdef HAVE_LIBNL - /* - * Bleah. There doesn't seem to be a way to ask a mac80211 - * device, through libnl, whether it supports monitor mode; - * we'll just check whether the device appears to be a - * mac80211 device and, if so, assume the device supports - * monitor mode. - * - * wmaster devices don't appear to support the Wireless - * Extensions, but we can create a mon device for a - * wmaster device, so we don't bother checking whether - * a mac80211 device supports the Wireless Extensions. - */ - ret = get_mac80211_phydev(handle, handle->opt.source, phydev_path, - PATH_MAX); - if (ret < 0) - return ret; /* error */ - if (ret == 1) - return 1; /* mac80211 device */ -#endif +/* + * Is this a mac80211 device? If so, fill in the physical device path and + * return 1; if not, return 0. On an error, fill in handle->errbuf and + * return PCAP_ERROR. + */ +static int +get_mac80211_phydev(pcap_t *handle, const char *device, char *phydev_path, + size_t phydev_max_pathlen) +{ + char *pathstr; + ssize_t bytes_read; -#ifdef IW_MODE_MONITOR /* - * Bleah. There doesn't appear to be an ioctl to use to ask - * whether a device supports monitor mode; we'll just do - * SIOCGIWMODE and, if it succeeds, assume the device supports - * monitor mode. - * - * Open a socket on which to attempt to get the mode. - * (We assume that if we have Wireless Extensions support - * we also have PF_PACKET support.) + * Generate the path string for the symlink to the physical device. */ - sock_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); - if (sock_fd == -1) { - (void)snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "socket: %s", pcap_strerror(errno)); + if (asprintf(&pathstr, "/sys/class/net/%s/phy80211", device) == -1) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: Can't generate path name string for /sys/class/net device", + device); return PCAP_ERROR; } - - /* - * Attempt to get the current mode. - */ - strncpy(ireq.ifr_ifrn.ifrn_name, handle->opt.source, - sizeof ireq.ifr_ifrn.ifrn_name); - ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; - if (ioctl(sock_fd, SIOCGIWMODE, &ireq) != -1) { - /* - * Well, we got the mode; assume we can set it. - */ - close(sock_fd); - return 1; - } - if (errno == ENODEV) { - /* The device doesn't even exist. */ - close(sock_fd); - return PCAP_ERROR_NO_SUCH_DEVICE; + bytes_read = readlink(pathstr, phydev_path, phydev_max_pathlen); + if (bytes_read == -1) { + if (errno == ENOENT || errno == EINVAL) { + /* + * Doesn't exist, or not a symlink; assume that + * means it's not a mac80211 device. + */ + free(pathstr); + return 0; + } + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: Can't readlink %s: %s", device, pathstr, + strerror(errno)); + free(pathstr); + return PCAP_ERROR; } - close(sock_fd); -#endif - return 0; + free(pathstr); + phydev_path[bytes_read] = '\0'; + return 1; } -#ifdef HAVE_LIBNL +#ifdef HAVE_LIBNL_2_x +#define get_nl_errmsg nl_geterror +#else +/* libnl 2.x compatibility code */ + +#define nl_sock nl_handle + +static inline struct nl_handle * +nl_socket_alloc(void) +{ + return nl_handle_alloc(); +} + +static inline void +nl_socket_free(struct nl_handle *h) +{ + nl_handle_destroy(h); +} + +#define get_nl_errmsg strerror + +static inline int +__genl_ctrl_alloc_cache(struct nl_handle *h, struct nl_cache **cache) +{ + struct nl_cache *tmp = genl_ctrl_alloc_cache(h); + if (!tmp) + return -ENOMEM; + *cache = tmp; + return 0; +} +#define genl_ctrl_alloc_cache __genl_ctrl_alloc_cache +#endif /* !HAVE_LIBNL_2_x */ struct nl80211_state { - struct nl_handle *nl_handle; + struct nl_sock *nl_sock; struct nl_cache *nl_cache; struct genl_family *nl80211; }; @@ -474,23 +578,26 @@ struct nl80211_state { static int nl80211_init(pcap_t *handle, struct nl80211_state *state, const char *device) { - state->nl_handle = nl_handle_alloc(); - if (!state->nl_handle) { + int err; + + state->nl_sock = nl_socket_alloc(); + if (!state->nl_sock) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "%s: failed to allocate netlink handle", device); return PCAP_ERROR; } - if (genl_connect(state->nl_handle)) { + if (genl_connect(state->nl_sock)) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "%s: failed to connect to generic netlink", device); goto out_handle_destroy; } - state->nl_cache = genl_ctrl_alloc_cache(state->nl_handle); - if (!state->nl_cache) { + err = genl_ctrl_alloc_cache(state->nl_sock, &state->nl_cache); + if (err < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: failed to allocate generic netlink cache", device); + "%s: failed to allocate generic netlink cache: %s", + device, get_nl_errmsg(-err)); goto out_handle_destroy; } @@ -506,7 +613,7 @@ nl80211_init(pcap_t *handle, struct nl80211_state *state, const char *device) out_cache_free: nl_cache_free(state->nl_cache); out_handle_destroy: - nl_handle_destroy(state->nl_handle); + nl_socket_free(state->nl_sock); return PCAP_ERROR; } @@ -515,7 +622,7 @@ nl80211_cleanup(struct nl80211_state *state) { genl_family_put(state->nl80211); nl_cache_free(state->nl_cache); - nl_handle_destroy(state->nl_handle); + nl_socket_free(state->nl_sock); } static int @@ -543,12 +650,19 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, mondevice); NLA_PUT_U32(msg, NL80211_ATTR_IFTYPE, NL80211_IFTYPE_MONITOR); - err = nl_send_auto_complete(state->nl_handle, msg); + err = nl_send_auto_complete(state->nl_sock, msg); if (err < 0) { +#ifdef HAVE_LIBNL_2_x + if (err == -NLE_FAILURE) { +#else if (err == -ENFILE) { +#endif /* * Device not available; our caller should just - * keep trying. + * keep trying. (libnl 2.x maps ENFILE to + * NLE_FAILURE; it can also map other errors + * to that, but there's not much we can do + * about that.) */ nlmsg_free(msg); return 0; @@ -559,17 +673,24 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, */ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "%s: nl_send_auto_complete failed adding %s interface: %s", - device, mondevice, strerror(-err)); + device, mondevice, get_nl_errmsg(-err)); nlmsg_free(msg); return PCAP_ERROR; } } - err = nl_wait_for_ack(state->nl_handle); + err = nl_wait_for_ack(state->nl_sock); if (err < 0) { +#ifdef HAVE_LIBNL_2_x + if (err == -NLE_FAILURE) { +#else if (err == -ENFILE) { +#endif /* * Device not available; our caller should just - * keep trying. + * keep trying. (libnl 2.x maps ENFILE to + * NLE_FAILURE; it can also map other errors + * to that, but there's not much we can do + * about that.) */ nlmsg_free(msg); return 0; @@ -580,7 +701,7 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, */ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "%s: nl_wait_for_ack failed adding %s interface: %s", - device, mondevice, strerror(-err)); + device, mondevice, get_nl_errmsg(-err)); nlmsg_free(msg); return PCAP_ERROR; } @@ -600,87 +721,317 @@ nla_put_failure: return PCAP_ERROR; } -static int -del_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, - const char *device, const char *mondevice) +static int +del_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, + const char *device, const char *mondevice) +{ + int ifindex; + struct nl_msg *msg; + int err; + + ifindex = iface_get_id(sock_fd, mondevice, handle->errbuf); + if (ifindex == -1) + return PCAP_ERROR; + + msg = nlmsg_alloc(); + if (!msg) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: failed to allocate netlink msg", device); + return PCAP_ERROR; + } + + genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0, + 0, NL80211_CMD_DEL_INTERFACE, 0); + NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex); + + err = nl_send_auto_complete(state->nl_sock, msg); + if (err < 0) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: nl_send_auto_complete failed deleting %s interface: %s", + device, mondevice, get_nl_errmsg(-err)); + nlmsg_free(msg); + return PCAP_ERROR; + } + err = nl_wait_for_ack(state->nl_sock); + if (err < 0) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: nl_wait_for_ack failed adding %s interface: %s", + device, mondevice, get_nl_errmsg(-err)); + nlmsg_free(msg); + return PCAP_ERROR; + } + + /* + * Success. + */ + nlmsg_free(msg); + return 1; + +nla_put_failure: + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: nl_put failed deleting %s interface", + device, mondevice); + nlmsg_free(msg); + return PCAP_ERROR; +} + +static int +enter_rfmon_mode_mac80211(pcap_t *handle, int sock_fd, const char *device) +{ + int ret; + char phydev_path[PATH_MAX+1]; + struct nl80211_state nlstate; + struct ifreq ifr; + u_int n; + + /* + * Is this a mac80211 device? + */ + ret = get_mac80211_phydev(handle, device, phydev_path, PATH_MAX); + if (ret < 0) + return ret; /* error */ + if (ret == 0) + return 0; /* no error, but not mac80211 device */ + + /* + * XXX - is this already a monN device? + * If so, we're done. + * Is that determined by old Wireless Extensions ioctls? + */ + + /* + * OK, it's apparently a mac80211 device. + * Try to find an unused monN device for it. + */ + ret = nl80211_init(handle, &nlstate, device); + if (ret != 0) + return ret; + for (n = 0; n < UINT_MAX; n++) { + /* + * Try mon{n}. + */ + char mondevice[3+10+1]; /* mon{UINT_MAX}\0 */ + + snprintf(mondevice, sizeof mondevice, "mon%u", n); + ret = add_mon_if(handle, sock_fd, &nlstate, device, mondevice); + if (ret == 1) { + handle->md.mondevice = strdup(mondevice); + goto added; + } + if (ret < 0) { + /* + * Hard failure. Just return ret; handle->errbuf + * has already been set. + */ + nl80211_cleanup(&nlstate); + return ret; + } + } + + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: No free monN interfaces", device); + nl80211_cleanup(&nlstate); + return PCAP_ERROR; + +added: + +#if 0 + /* + * Sleep for .1 seconds. + */ + delay.tv_sec = 0; + delay.tv_nsec = 500000000; + nanosleep(&delay, NULL); +#endif + + /* + * Now configure the monitor interface up. + */ + memset(&ifr, 0, sizeof(ifr)); + strncpy(ifr.ifr_name, handle->md.mondevice, sizeof(ifr.ifr_name)); + if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) == -1) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: Can't get flags for %s: %s", device, + handle->md.mondevice, strerror(errno)); + del_mon_if(handle, sock_fd, &nlstate, device, + handle->md.mondevice); + nl80211_cleanup(&nlstate); + return PCAP_ERROR; + } + ifr.ifr_flags |= IFF_UP|IFF_RUNNING; + if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: Can't set flags for %s: %s", device, + handle->md.mondevice, strerror(errno)); + del_mon_if(handle, sock_fd, &nlstate, device, + handle->md.mondevice); + nl80211_cleanup(&nlstate); + return PCAP_ERROR; + } + + /* + * Success. Clean up the libnl state. + */ + nl80211_cleanup(&nlstate); + + /* + * Note that we have to delete the monitor device when we close + * the handle. + */ + handle->md.must_do_on_close |= MUST_DELETE_MONIF; + + /* + * Add this to the list of pcaps to close when we exit. + */ + pcap_add_to_pcaps_to_close(handle); + + return 1; +} +#endif /* HAVE_LIBNL */ + +static int +pcap_can_set_rfmon_linux(pcap_t *handle) +{ +#ifdef HAVE_LIBNL + char phydev_path[PATH_MAX+1]; + int ret; +#endif +#ifdef IW_MODE_MONITOR + int sock_fd; + struct iwreq ireq; +#endif + + if (strcmp(handle->opt.source, "any") == 0) { + /* + * Monitor mode makes no sense on the "any" device. + */ + return 0; + } + +#ifdef HAVE_LIBNL + /* + * Bleah. There doesn't seem to be a way to ask a mac80211 + * device, through libnl, whether it supports monitor mode; + * we'll just check whether the device appears to be a + * mac80211 device and, if so, assume the device supports + * monitor mode. + * + * wmaster devices don't appear to support the Wireless + * Extensions, but we can create a mon device for a + * wmaster device, so we don't bother checking whether + * a mac80211 device supports the Wireless Extensions. + */ + ret = get_mac80211_phydev(handle, handle->opt.source, phydev_path, + PATH_MAX); + if (ret < 0) + return ret; /* error */ + if (ret == 1) + return 1; /* mac80211 device */ +#endif + +#ifdef IW_MODE_MONITOR + /* + * Bleah. There doesn't appear to be an ioctl to use to ask + * whether a device supports monitor mode; we'll just do + * SIOCGIWMODE and, if it succeeds, assume the device supports + * monitor mode. + * + * Open a socket on which to attempt to get the mode. + * (We assume that if we have Wireless Extensions support + * we also have PF_PACKET support.) + */ + sock_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); + if (sock_fd == -1) { + (void)snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "socket: %s", pcap_strerror(errno)); + return PCAP_ERROR; + } + + /* + * Attempt to get the current mode. + */ + strncpy(ireq.ifr_ifrn.ifrn_name, handle->opt.source, + sizeof ireq.ifr_ifrn.ifrn_name); + ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; + if (ioctl(sock_fd, SIOCGIWMODE, &ireq) != -1) { + /* + * Well, we got the mode; assume we can set it. + */ + close(sock_fd); + return 1; + } + if (errno == ENODEV) { + /* The device doesn't even exist. */ + (void)snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "SIOCGIWMODE failed: %s", pcap_strerror(errno)); + close(sock_fd); + return PCAP_ERROR_NO_SUCH_DEVICE; + } + close(sock_fd); +#endif + return 0; +} + +/* + * Grabs the number of dropped packets by the interface from /proc/net/dev. + * + * XXX - what about /sys/class/net/{interface name}/rx_*? There are + * individual devices giving, in ASCII, various rx_ and tx_ statistics. + * + * Or can we get them in binary form from netlink? + */ +static long int +linux_if_drops(const char * if_name) { - int ifindex; - struct nl_msg *msg; - int err; - - ifindex = iface_get_id(sock_fd, mondevice, handle->errbuf); - if (ifindex == -1) - return PCAP_ERROR; + char buffer[512]; + char * bufptr; + FILE * file; + int field_to_convert = 3, if_name_sz = strlen(if_name); + long int dropped_pkts = 0; + + file = fopen("/proc/net/dev", "r"); + if (!file) + return 0; - msg = nlmsg_alloc(); - if (!msg) { - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: failed to allocate netlink msg", device); - return PCAP_ERROR; - } + while (!dropped_pkts && fgets( buffer, sizeof(buffer), file )) + { + /* search for 'bytes' -- if its in there, then + that means we need to grab the fourth field. otherwise + grab the third field. */ + if (field_to_convert != 4 && strstr(buffer, "bytes")) + { + field_to_convert = 4; + continue; + } + + /* find iface and make sure it actually matches -- space before the name and : after it */ + if ((bufptr = strstr(buffer, if_name)) && + (bufptr == buffer || *(bufptr-1) == ' ') && + *(bufptr + if_name_sz) == ':') + { + bufptr = bufptr + if_name_sz + 1; - genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0, - 0, NL80211_CMD_DEL_INTERFACE, 0); - NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex); + /* grab the nth field from it */ + while( --field_to_convert && *bufptr != '\0') + { + while (*bufptr != '\0' && *(bufptr++) == ' '); + while (*bufptr != '\0' && *(bufptr++) != ' '); + } + + /* get rid of any final spaces */ + while (*bufptr != '\0' && *bufptr == ' ') bufptr++; + + if (*bufptr != '\0') + dropped_pkts = strtol(bufptr, NULL, 10); - err = nl_send_auto_complete(state->nl_handle, msg); - if (err < 0) { - if (err == -ENFILE) { - /* - * Device not available; our caller should just - * keep trying. - */ - nlmsg_free(msg); - return 0; - } else { - /* - * Real failure, not just "that device is not - * available. - */ - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: nl_send_auto_complete failed deleting %s interface: %s", - device, mondevice, strerror(-err)); - nlmsg_free(msg); - return PCAP_ERROR; - } - } - err = nl_wait_for_ack(state->nl_handle); - if (err < 0) { - if (err == -ENFILE) { - /* - * Device not available; our caller should just - * keep trying. - */ - nlmsg_free(msg); - return 0; - } else { - /* - * Real failure, not just "that device is not - * available. - */ - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: nl_wait_for_ack failed adding %s interface: %s", - device, mondevice, strerror(-err)); - nlmsg_free(msg); - return PCAP_ERROR; + break; } } + + fclose(file); + return dropped_pkts; +} - /* - * Success. - */ - nlmsg_free(msg); - return 1; - -nla_put_failure: - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: nl_put failed deleting %s interface", - device, mondevice); - nlmsg_free(msg); - return PCAP_ERROR; -} - -#endif /* HAVE_LIBNL */ /* * With older kernels promiscuous mode is kind of interesting because we @@ -857,6 +1208,14 @@ pcap_activate_linux(pcap_t *handle) pcap_strerror(errno) ); return PCAP_ERROR; } + + /* + * If we're in promiscuous mode, then we probably want + * to see when the interface drops packets too, so get an + * initial count from /proc/net/dev + */ + if (handle->opt.promisc) + handle->md.proc_dropped = linux_if_drops(handle->md.device); /* * Current Linux kernels use the protocol family PF_PACKET to @@ -867,34 +1226,46 @@ pcap_activate_linux(pcap_t *handle) * to be compatible with older kernels for a while so we are * trying both methods with the newer method preferred. */ - - if ((status = activate_new(handle)) == 1) { + status = activate_new(handle); + if (status < 0) { + /* + * Fatal error with the new way; just fail. + * status has the error return; if it's PCAP_ERROR, + * handle->errbuf has been set appropriately. + */ + goto fail; + } + if (status == 1) { /* * Success. * Try to use memory-mapped access. */ - switch (activate_mmap(handle)) { + switch (activate_mmap(handle, &status)) { case 1: - /* we succeeded; nothing more to do */ - return 0; + /* + * We succeeded. status has been + * set to the status to return, + * which might be 0, or might be + * a PCAP_WARNING_ value. + */ + return status; case 0: /* * Kernel doesn't support it - just continue * with non-memory-mapped access. */ - status = 0; break; case -1: /* - * We failed to set up to use it, or kernel - * supports it, but we failed to enable it; - * return an error. handle->errbuf contains - * an error message. + * We failed to set up to use it, or the kernel + * supports it, but we failed to enable it. + * status has been set to the error status to + * return and, if it's PCAP_ERROR, handle->errbuf + * contains the error message. */ - status = PCAP_ERROR; goto fail; } } @@ -908,18 +1279,12 @@ pcap_activate_linux(pcap_t *handle) */ goto fail; } - } else { - /* - * Fatal error with the new way; just fail. - * status has the error return; if it's PCAP_ERROR, - * handle->errbuf has been set appropriately. - */ - goto fail; } /* * We set up the socket, but not with memory-mapped access. */ + status = 0; if (handle->opt.buffer_size != 0) { /* * Set the socket buffer size to the specified value. @@ -1055,12 +1420,12 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) */ if (handle->break_loop) { /* - * Yes - clear the flag that indicates that it - * has, and return -2 as an indication that we - * were told to break out of the loop. + * Yes - clear the flag that indicates that it has, + * and return PCAP_ERROR_BREAK as an indication that + * we were told to break out of the loop. */ handle->break_loop = 0; - return -2; + return PCAP_ERROR_BREAK; } #if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) @@ -1072,17 +1437,32 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) handle->bufsize - offset, MSG_TRUNC, (struct sockaddr *) &from, &fromlen); #endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ - } while (packet_len == -1 && (errno == EINTR || errno == ENETDOWN)); + } while (packet_len == -1 && errno == EINTR); /* Check if an error occured */ if (packet_len == -1) { - if (errno == EAGAIN) + switch (errno) { + + case EAGAIN: return 0; /* no packet there */ - else { + + case ENETDOWN: + /* + * The device on which we're capturing went away. + * + * XXX - we should really return + * PCAP_ERROR_IFACE_NOT_UP, but pcap_dispatch() + * etc. aren't defined to return that. + */ + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "The interface went down"); + return PCAP_ERROR; + + default: snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "recvfrom: %s", pcap_strerror(errno)); - return -1; + return PCAP_ERROR; } } @@ -1240,7 +1620,7 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) if (ioctl(handle->fd, SIOCGSTAMP, &pcap_header.ts) == -1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "SIOCGSTAMP: %s", pcap_strerror(errno)); - return -1; + return PCAP_ERROR; } pcap_header.caplen = caplen; pcap_header.len = packet_len; @@ -1355,6 +1735,18 @@ pcap_stats_linux(pcap_t *handle, struct pcap_stat *stats) socklen_t len = sizeof (struct tpacket_stats); #endif + long if_dropped = 0; + + /* + * To fill in ps_ifdrop, we parse /proc/net/dev for the number + */ + if (handle->opt.promisc) + { + if_dropped = handle->md.proc_dropped; + handle->md.proc_dropped = linux_if_drops(handle->md.device); + handle->md.stat.ps_ifdrop += (handle->md.proc_dropped - if_dropped); + } + #ifdef HAVE_TPACKET_STATS /* * Try to get the packet counts from the kernel. @@ -1375,6 +1767,8 @@ pcap_stats_linux(pcap_t *handle, struct pcap_stat *stats) * dropped by the interface driver. It counts only * packets that passed the filter. * + * See above for ps_ifdrop. + * * Both statistics include packets not yet read from * the kernel by libpcap, and thus not yet seen by * the application. @@ -1426,29 +1820,311 @@ pcap_stats_linux(pcap_t *handle, struct pcap_stat *stats) return -1; } } -#endif - /* - * On systems where the PACKET_STATISTICS "getsockopt()" argument - * is not supported on PF_PACKET sockets: - * - * "ps_recv" counts only packets that *passed* the filter, - * not packets that didn't pass the filter. It does not - * count packets dropped because we ran out of buffer - * space. - * - * "ps_drop" is not supported. - * - * "ps_recv" doesn't include packets not yet read from - * the kernel by libpcap. - * - * We maintain the count of packets processed by libpcap in - * "md.packets_read", for reasons described in the comment - * at the end of pcap_read_packet(). We have no idea how many - * packets were dropped. - */ - stats->ps_recv = handle->md.packets_read; - stats->ps_drop = 0; - return 0; +#endif + /* + * On systems where the PACKET_STATISTICS "getsockopt()" argument + * is not supported on PF_PACKET sockets: + * + * "ps_recv" counts only packets that *passed* the filter, + * not packets that didn't pass the filter. It does not + * count packets dropped because we ran out of buffer + * space. + * + * "ps_drop" is not supported. + * + * "ps_ifdrop" is supported. It will return the number + * of drops the interface reports in /proc/net/dev, + * if that is available. + * + * "ps_recv" doesn't include packets not yet read from + * the kernel by libpcap. + * + * We maintain the count of packets processed by libpcap in + * "md.packets_read", for reasons described in the comment + * at the end of pcap_read_packet(). We have no idea how many + * packets were dropped by the kernel buffers -- but we know + * how many the interface dropped, so we can return that. + */ + + stats->ps_recv = handle->md.packets_read; + stats->ps_drop = 0; + stats->ps_ifdrop = handle->md.stat.ps_ifdrop; + return 0; +} + +/* + * Get from "/sys/class/net" all interfaces listed there; if they're + * already in the list of interfaces we have, that won't add another + * instance, but if they're not, that'll add them. + * + * We don't bother getting any addresses for them; it appears you can't + * use SIOCGIFADDR on Linux to get IPv6 addresses for interfaces, and, + * although some other types of addresses can be fetched with SIOCGIFADDR, + * we don't bother with them for now. + * + * We also don't fail if we couldn't open "/sys/class/net"; we just leave + * the list of interfaces as is, and return 0, so that we can try + * scanning /proc/net/dev. + */ +static int +scan_sys_class_net(pcap_if_t **devlistp, char *errbuf) +{ + DIR *sys_class_net_d; + int fd; + struct dirent *ent; + char *p; + char name[512]; /* XXX - pick a size */ + char *q, *saveq; + struct ifreq ifrflags; + int ret = 1; + + sys_class_net_d = opendir("/sys/class/net"); + if (sys_class_net_d == NULL && errno == ENOENT) + return (0); + + /* + * Create a socket from which to fetch interface information. + */ + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd < 0) { + (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, + "socket: %s", pcap_strerror(errno)); + (void)closedir(sys_class_net_d); + return (-1); + } + + for (;;) { + errno = 0; + ent = readdir(sys_class_net_d); + if (ent == NULL) { + /* + * Error or EOF; if errno != 0, it's an error. + */ + break; + } + + /* + * Ignore directories (".", "..", and any subdirectories). + */ + if (ent->d_type == DT_DIR) + continue; + + /* + * Get the interface name. + */ + p = &ent->d_name[0]; + q = &name[0]; + while (*p != '\0' && isascii(*p) && !isspace(*p)) { + if (*p == ':') { + /* + * This could be the separator between a + * name and an alias number, or it could be + * the separator between a name with no + * alias number and the next field. + * + * If there's a colon after digits, it + * separates the name and the alias number, + * otherwise it separates the name and the + * next field. + */ + saveq = q; + while (isascii(*p) && isdigit(*p)) + *q++ = *p++; + if (*p != ':') { + /* + * That was the next field, + * not the alias number. + */ + q = saveq; + } + break; + } else + *q++ = *p++; + } + *q = '\0'; + + /* + * Get the flags for this interface, and skip it if + * it's not up. + */ + strncpy(ifrflags.ifr_name, name, sizeof(ifrflags.ifr_name)); + if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { + if (errno == ENXIO || errno == ENODEV) + continue; + (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, + "SIOCGIFFLAGS: %.*s: %s", + (int)sizeof(ifrflags.ifr_name), + ifrflags.ifr_name, + pcap_strerror(errno)); + ret = -1; + break; + } + if (!(ifrflags.ifr_flags & IFF_UP)) + continue; + + /* + * Add an entry for this interface, with no addresses. + */ + if (pcap_add_if(devlistp, name, ifrflags.ifr_flags, NULL, + errbuf) == -1) { + /* + * Failure. + */ + ret = -1; + break; + } + } + if (ret != -1) { + /* + * Well, we didn't fail for any other reason; did we + * fail due to an error reading the directory? + */ + if (errno != 0) { + (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Error reading /sys/class/net: %s", + pcap_strerror(errno)); + ret = -1; + } + } + + (void)close(fd); + (void)closedir(sys_class_net_d); + return (ret); +} + +/* + * Get from "/proc/net/dev" all interfaces listed there; if they're + * already in the list of interfaces we have, that won't add another + * instance, but if they're not, that'll add them. + * + * See comments from scan_sys_class_net(). + */ +static int +scan_proc_net_dev(pcap_if_t **devlistp, char *errbuf) +{ + FILE *proc_net_f; + int fd; + char linebuf[512]; + int linenum; + char *p; + char name[512]; /* XXX - pick a size */ + char *q, *saveq; + struct ifreq ifrflags; + int ret = 0; + + proc_net_f = fopen("/proc/net/dev", "r"); + if (proc_net_f == NULL && errno == ENOENT) + return (0); + + /* + * Create a socket from which to fetch interface information. + */ + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd < 0) { + (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, + "socket: %s", pcap_strerror(errno)); + (void)fclose(proc_net_f); + return (-1); + } + + for (linenum = 1; + fgets(linebuf, sizeof linebuf, proc_net_f) != NULL; linenum++) { + /* + * Skip the first two lines - they're headers. + */ + if (linenum <= 2) + continue; + + p = &linebuf[0]; + + /* + * Skip leading white space. + */ + while (*p != '\0' && isascii(*p) && isspace(*p)) + p++; + if (*p == '\0' || *p == '\n') + continue; /* blank line */ + + /* + * Get the interface name. + */ + q = &name[0]; + while (*p != '\0' && isascii(*p) && !isspace(*p)) { + if (*p == ':') { + /* + * This could be the separator between a + * name and an alias number, or it could be + * the separator between a name with no + * alias number and the next field. + * + * If there's a colon after digits, it + * separates the name and the alias number, + * otherwise it separates the name and the + * next field. + */ + saveq = q; + while (isascii(*p) && isdigit(*p)) + *q++ = *p++; + if (*p != ':') { + /* + * That was the next field, + * not the alias number. + */ + q = saveq; + } + break; + } else + *q++ = *p++; + } + *q = '\0'; + + /* + * Get the flags for this interface, and skip it if + * it's not up. + */ + strncpy(ifrflags.ifr_name, name, sizeof(ifrflags.ifr_name)); + if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { + if (errno == ENXIO) + continue; + (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, + "SIOCGIFFLAGS: %.*s: %s", + (int)sizeof(ifrflags.ifr_name), + ifrflags.ifr_name, + pcap_strerror(errno)); + ret = -1; + break; + } + if (!(ifrflags.ifr_flags & IFF_UP)) + continue; + + /* + * Add an entry for this interface, with no addresses. + */ + if (pcap_add_if(devlistp, name, ifrflags.ifr_flags, NULL, + errbuf) == -1) { + /* + * Failure. + */ + ret = -1; + break; + } + } + if (ret != -1) { + /* + * Well, we didn't fail for any other reason; did we + * fail due to an error reading the file? + */ + if (ferror(proc_net_f)) { + (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Error reading /proc/net/dev: %s", + pcap_strerror(errno)); + ret = -1; + } + } + + (void)close(fd); + (void)fclose(proc_net_f); + return (ret); } /* @@ -1459,25 +2135,66 @@ static const char any_descr[] = "Pseudo-device that captures on all interfaces"; int pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) { + int ret; + + /* + * Read "/sys/class/net", and add to the list of interfaces all + * interfaces listed there that we don't already have, because, + * on Linux, SIOCGIFCONF reports only interfaces with IPv4 addresses, + * and even getifaddrs() won't return information about + * interfaces with no addresses, so you need to read "/sys/class/net" + * to get the names of the rest of the interfaces. + */ + ret = scan_sys_class_net(alldevsp, errbuf); + if (ret == -1) + return (-1); /* failed */ + if (ret == 0) { + /* + * No /sys/class/net; try reading /proc/net/dev instead. + */ + if (scan_proc_net_dev(alldevsp, errbuf) == -1) + return (-1); + } + + /* + * Add the "any" device. + */ if (pcap_add_if(alldevsp, "any", 0, any_descr, errbuf) < 0) return (-1); #ifdef HAVE_DAG_API + /* + * Add DAG devices. + */ if (dag_platform_finddevs(alldevsp, errbuf) < 0) return (-1); #endif /* HAVE_DAG_API */ #ifdef HAVE_SEPTEL_API + /* + * Add Septel devices. + */ if (septel_platform_finddevs(alldevsp, errbuf) < 0) return (-1); #endif /* HAVE_SEPTEL_API */ +#ifdef HAVE_SNF_API + if (snf_platform_finddevs(alldevsp, errbuf) < 0) + return (-1); +#endif /* HAVE_SNF_API */ + #ifdef PCAP_SUPPORT_BT + /* + * Add Bluetooth devices. + */ if (bt_platform_finddevs(alldevsp, errbuf) < 0) return (-1); #endif #ifdef PCAP_SUPPORT_USB + /* + * Add USB devices. + */ if (usb_platform_finddevs(alldevsp, errbuf) < 0) return (-1); #endif @@ -1489,7 +2206,8 @@ pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) * Attach the given BPF code to the packet capture device. */ static int -pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) +pcap_setfilter_linux_common(pcap_t *handle, struct bpf_program *filter, + int is_mmapped) { #ifdef SO_ATTACH_FILTER struct sock_fprog fcode; @@ -1542,13 +2260,13 @@ pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) * * Oh, and we also need to fix it up so that all "ret" * instructions with non-zero operands have 65535 as the - * operand, and so that, if we're in cooked mode, all - * memory-reference instructions use special magic offsets - * in references to the link-layer header and assume that - * the link-layer payload begins at 0; "fix_program()" - * will do that. + * operand if we're not capturing in memory-mapped modee, + * and so that, if we're in cooked mode, all memory-reference + * instructions use special magic offsets in references to + * the link-layer header and assume that the link-layer + * payload begins at 0; "fix_program()" will do that. */ - switch (fix_program(handle, &fcode)) { + switch (fix_program(handle, &fcode, is_mmapped)) { case -1: default: @@ -1576,6 +2294,30 @@ pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) } } + /* + * NOTE: at this point, we've set both the "len" and "filter" + * fields of "fcode". As of the 2.6.32.4 kernel, at least, + * those are the only members of the "sock_fprog" structure, + * so we initialize every member of that structure. + * + * If there is anything in "fcode" that is not initialized, + * it is either a field added in a later kernel, or it's + * padding. + * + * If a new field is added, this code needs to be updated + * to set it correctly. + * + * If there are no other fields, then: + * + * if the Linux kernel looks at the padding, it's + * buggy; + * + * if the Linux kernel doesn't look at the padding, + * then if some tool complains that we're passing + * uninitialized data to the kernel, then the tool + * is buggy and needs to understand that it's just + * padding. + */ if (can_filter_in_kernel) { if ((err = set_kernel_filter(handle, &fcode)) == 0) { @@ -1622,6 +2364,13 @@ pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) return 0; } +static int +pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) +{ + return pcap_setfilter_linux_common(handle, filter, 0); +} + + /* * Set direction flag: Which packets do we accept on a forwarding * single device? IN, OUT or both? @@ -1644,7 +2393,6 @@ pcap_setdirection_linux(pcap_t *handle, pcap_direction_t d) return -1; } - #ifdef HAVE_PF_PACKET_SOCKETS /* * Map the PACKET_ value to a LINUX_SLL_ value; we @@ -1752,6 +2500,12 @@ static void map_arphrd_to_dlt(pcap_t *handle, int arptype, int cooked_ok) case ARPHRD_CHAOS: handle->linktype = DLT_CHAOS; break; +#ifndef ARPHRD_CAN +#define ARPHRD_CAN 280 +#endif + case ARPHRD_CAN: + handle->linktype = DLT_CAN_SOCKETCAN; + break; #ifndef ARPHRD_IEEE802_TR #define ARPHRD_IEEE802_TR 800 /* From Linux 2.4 */ @@ -1985,6 +2739,13 @@ static void map_arphrd_to_dlt(pcap_t *handle, int arptype, int cooked_ok) handle->linktype = DLT_RAW; break; +#ifndef ARPHRD_IEEE802154 +#define ARPHRD_IEEE802154 804 +#endif + case ARPHRD_IEEE802154: + handle->linktype = DLT_IEEE802_15_4_NOFCS; + break; + default: handle->linktype = -1; break; @@ -2006,7 +2767,10 @@ activate_new(pcap_t *handle) #ifdef HAVE_PF_PACKET_SOCKETS const char *device = handle->opt.source; int is_any_device = (strcmp(device, "any") == 0); - int sock_fd = -1, arptype, val; + int sock_fd = -1, arptype; +#ifdef HAVE_PACKET_AUXDATA + int val; +#endif int err = 0; struct packet_mreq mr; @@ -2283,40 +3047,97 @@ activate_new(pcap_t *handle) #endif } +#ifdef HAVE_PACKET_RING +/* + * Attempt to activate with memory-mapped access. + * + * On success, returns 1, and sets *status to 0 if there are no warnings + * or to a PCAP_WARNING_ code if there is a warning. + * + * On failure due to lack of support for memory-mapped capture, returns + * 0. + * + * On error, returns -1, and sets *status to the appropriate error code; + * if that is PCAP_ERROR, sets handle->errbuf to the appropriate message. + */ static int -activate_mmap(pcap_t *handle) +activate_mmap(pcap_t *handle, int *status) { -#ifdef HAVE_PACKET_RING int ret; + /* + * Attempt to allocate a buffer to hold the contents of one + * packet, for use by the oneshot callback. + */ + handle->md.oneshot_buffer = malloc(handle->snapshot); + if (handle->md.oneshot_buffer == NULL) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't allocate oneshot buffer: %s", + pcap_strerror(errno)); + *status = PCAP_ERROR; + return -1; + } + if (handle->opt.buffer_size == 0) { /* by default request 2M for the ring buffer */ handle->opt.buffer_size = 2*1024*1024; } ret = prepare_tpacket_socket(handle); - if (ret != 1) - return ret; - ret = create_ring(handle); - if (ret != 1) + if (ret == -1) { + free(handle->md.oneshot_buffer); + *status = PCAP_ERROR; return ret; + } + ret = create_ring(handle, status); + if (ret == 0) { + /* + * We don't support memory-mapped capture; our caller + * will fall back on reading from the socket. + */ + free(handle->md.oneshot_buffer); + return 0; + } + if (ret == -1) { + /* + * Error attempting to enable memory-mapped capture; + * fail. create_ring() has set *status. + */ + free(handle->md.oneshot_buffer); + return -1; + } - /* override some defaults and inherit the other fields from - * activate_new - * handle->offset is used to get the current position into the rx ring - * handle->cc is used to store the ring size */ + /* + * Success. *status has been set either to 0 if there are no + * warnings or to a PCAP_WARNING_ value if there is a warning. + * + * Override some defaults and inherit the other fields from + * activate_new. + * handle->offset is used to get the current position into the rx ring. + * handle->cc is used to store the ring size. + */ handle->read_op = pcap_read_linux_mmap; handle->cleanup_op = pcap_cleanup_linux_mmap; handle->setfilter_op = pcap_setfilter_linux_mmap; handle->setnonblock_op = pcap_setnonblock_mmap; handle->getnonblock_op = pcap_getnonblock_mmap; + handle->oneshot_callback = pcap_oneshot_mmap; handle->selectable_fd = handle->fd; return 1; +} #else /* HAVE_PACKET_RING */ +static int +activate_mmap(pcap_t *handle _U_, int *status _U_) +{ return 0; -#endif /* HAVE_PACKET_RING */ } +#endif /* HAVE_PACKET_RING */ #ifdef HAVE_PACKET_RING +/* + * Attempt to set the socket to version 2 of the memory-mapped header. + * Return 1 if we succeed or if we fail because version 2 isn't + * supported; return -1 on any other error, and set handle->errbuf. + */ static int prepare_tpacket_socket(pcap_t *handle) { @@ -2368,49 +3189,278 @@ prepare_tpacket_socket(pcap_t *handle) return 1; } -static void -compute_ring_block(int frame_size, unsigned *block_size, unsigned *frames_per_block) +/* + * Attempt to set up memory-mapped access. + * + * On success, returns 1, and sets *status to 0 if there are no warnings + * or to a PCAP_WARNING_ code if there is a warning. + * + * On failure due to lack of support for memory-mapped capture, returns + * 0. + * + * On error, returns -1, and sets *status to the appropriate error code; + * if that is PCAP_ERROR, sets handle->errbuf to the appropriate message. + */ +static int +create_ring(pcap_t *handle, int *status) { + unsigned i, j, frames_per_block; + struct tpacket_req req; + socklen_t len; + unsigned int sk_type, tp_reserve, maclen, tp_hdrlen, netoff, macoff; + unsigned int frame_size; + + /* + * Start out assuming no warnings or errors. + */ + *status = 0; + + /* Note that with large snapshot length (say 64K, which is the default + * for recent versions of tcpdump, the value that "-s 0" has given + * for a long time with tcpdump, and the default in Wireshark/TShark), + * if we use the snapshot length to calculate the frame length, + * only a few frames will be available in the ring even with pretty + * large ring size (and a lot of memory will be unused). + * + * Ideally, we should choose a frame length based on the + * minimum of the specified snapshot length and the maximum + * packet size. That's not as easy as it sounds; consider, for + * example, an 802.11 interface in monitor mode, where the + * frame would include a radiotap header, where the maximum + * radiotap header length is device-dependent. + * + * So, for now, we just do this for Ethernet devices, where + * there's no metadata header, and the link-layer header is + * fixed length. We can get the maximum packet size by + * adding 18, the Ethernet header length plus the CRC length + * (just in case we happen to get the CRC in the packet), to + * the MTU of the interface; we fetch the MTU in the hopes + * that it reflects support for jumbo frames. (Even if the + * interface is just being used for passive snooping, the driver + * might set the size of buffers in the receive ring based on + * the MTU, so that the MTU limits the maximum size of packets + * that we can receive.) + * + * We don't do that if segmentation/fragmentation or receive + * offload are enabled, so we don't get rudely surprised by + * "packets" bigger than the MTU. */ + frame_size = handle->snapshot; + if (handle->linktype == DLT_EN10MB) { + int mtu; + int offload; + + offload = iface_get_offload(handle); + if (offload == -1) { + *status = PCAP_ERROR; + return -1; + } + if (!offload) { + mtu = iface_get_mtu(handle->fd, handle->opt.source, + handle->errbuf); + if (mtu == -1) { + *status = PCAP_ERROR; + return -1; + } + if (frame_size > mtu + 18) + frame_size = mtu + 18; + } + } + + /* NOTE: calculus matching those in tpacket_rcv() + * in linux-2.6/net/packet/af_packet.c + */ + len = sizeof(sk_type); + if (getsockopt(handle->fd, SOL_SOCKET, SO_TYPE, &sk_type, &len) < 0) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "getsockopt: %s", pcap_strerror(errno)); + *status = PCAP_ERROR; + return -1; + } +#ifdef PACKET_RESERVE + len = sizeof(tp_reserve); + if (getsockopt(handle->fd, SOL_PACKET, PACKET_RESERVE, &tp_reserve, &len) < 0) { + if (errno != ENOPROTOOPT) { + /* + * ENOPROTOOPT means "kernel doesn't support + * PACKET_RESERVE", in which case we fall back + * as best we can. + */ + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "getsockopt: %s", pcap_strerror(errno)); + *status = PCAP_ERROR; + return -1; + } + tp_reserve = 0; /* older kernel, reserve not supported */ + } +#else + tp_reserve = 0; /* older kernel, reserve not supported */ +#endif + maclen = (sk_type == SOCK_DGRAM) ? 0 : MAX_LINKHEADER_SIZE; + /* XXX: in the kernel maclen is calculated from + * LL_ALLOCATED_SPACE(dev) and vnet_hdr.hdr_len + * in: packet_snd() in linux-2.6/net/packet/af_packet.c + * then packet_alloc_skb() in linux-2.6/net/packet/af_packet.c + * then sock_alloc_send_pskb() in linux-2.6/net/core/sock.c + * but I see no way to get those sizes in userspace, + * like for instance with an ifreq ioctl(); + * the best thing I've found so far is MAX_HEADER in the kernel + * part of linux-2.6/include/linux/netdevice.h + * which goes up to 128+48=176; since pcap-linux.c defines + * a MAX_LINKHEADER_SIZE of 256 which is greater than that, + * let's use it.. maybe is it even large enough to directly + * replace macoff.. + */ + tp_hdrlen = TPACKET_ALIGN(handle->md.tp_hdrlen) + sizeof(struct sockaddr_ll) ; + netoff = TPACKET_ALIGN(tp_hdrlen + (maclen < 16 ? 16 : maclen)) + tp_reserve; + /* NOTE: AFAICS tp_reserve may break the TPACKET_ALIGN of + * netoff, which contradicts + * linux-2.6/Documentation/networking/packet_mmap.txt + * documenting that: + * "- Gap, chosen so that packet data (Start+tp_net) + * aligns to TPACKET_ALIGNMENT=16" + */ + /* NOTE: in linux-2.6/include/linux/skbuff.h: + * "CPUs often take a performance hit + * when accessing unaligned memory locations" + */ + macoff = netoff - maclen; + req.tp_frame_size = TPACKET_ALIGN(macoff + frame_size); + req.tp_frame_nr = handle->opt.buffer_size/req.tp_frame_size; + /* compute the minumum block size that will handle this frame. * The block has to be page size aligned. * The max block size allowed by the kernel is arch-dependent and * it's not explicitly checked here. */ - *block_size = getpagesize(); - while (*block_size < frame_size) - *block_size <<= 1; + req.tp_block_size = getpagesize(); + while (req.tp_block_size < req.tp_frame_size) + req.tp_block_size <<= 1; - *frames_per_block = *block_size/frame_size; -} + frames_per_block = req.tp_block_size/req.tp_frame_size; -static int -create_ring(pcap_t *handle) -{ - unsigned i, j, ringsize, frames_per_block; - struct tpacket_req req; + /* + * PACKET_TIMESTAMP was added after linux/net_tstamp.h was, + * so we check for PACKET_TIMESTAMP. We check for + * linux/net_tstamp.h just in case a system somehow has + * PACKET_TIMESTAMP but not linux/net_tstamp.h; that might + * be unnecessary. + * + * SIOCSHWTSTAMP was introduced in the patch that introduced + * linux/net_tstamp.h, so we don't bother checking whether + * SIOCSHWTSTAMP is defined (if your Linux system has + * linux/net_tstamp.h but doesn't define SIOCSHWTSTAMP, your + * Linux system is badly broken). + */ +#if defined(HAVE_LINUX_NET_TSTAMP_H) && defined(PACKET_TIMESTAMP) + /* + * If we were told to do so, ask the kernel and the driver + * to use hardware timestamps. + * + * Hardware timestamps are only supported with mmapped + * captures. + */ + if (handle->opt.tstamp_type == PCAP_TSTAMP_ADAPTER || + handle->opt.tstamp_type == PCAP_TSTAMP_ADAPTER_UNSYNCED) { + struct hwtstamp_config hwconfig; + struct ifreq ifr; + int timesource; - /* Note that with large snapshot (say 64K) only a few frames - * will be available in the ring even with pretty large ring size - * (and a lot of memory will be unused). - * The snap len should be carefully chosen to achive best - * performance */ - req.tp_frame_size = TPACKET_ALIGN(handle->snapshot + - TPACKET_ALIGN(handle->md.tp_hdrlen) + - sizeof(struct sockaddr_ll)); - req.tp_frame_nr = handle->opt.buffer_size/req.tp_frame_size; - compute_ring_block(req.tp_frame_size, &req.tp_block_size, &frames_per_block); - req.tp_block_nr = req.tp_frame_nr / frames_per_block; + /* + * Ask for hardware time stamps on all packets, + * including transmitted packets. + */ + memset(&hwconfig, 0, sizeof(hwconfig)); + hwconfig.tx_type = HWTSTAMP_TX_ON; + hwconfig.rx_filter = HWTSTAMP_FILTER_ALL; - /* req.tp_frame_nr is requested to match frames_per_block*req.tp_block_nr */ - req.tp_frame_nr = req.tp_block_nr * frames_per_block; + memset(&ifr, 0, sizeof(ifr)); + strcpy(ifr.ifr_name, handle->opt.source); + ifr.ifr_data = (void *)&hwconfig; + + if (ioctl(handle->fd, SIOCSHWTSTAMP, &ifr) < 0) { + switch (errno) { + + case EPERM: + /* + * Treat this as an error, as the + * user should try to run this + * with the appropriate privileges - + * and, if they can't, shouldn't + * try requesting hardware time stamps. + */ + *status = PCAP_ERROR_PERM_DENIED; + return -1; + + case EOPNOTSUPP: + /* + * Treat this as a warning, as the + * only way to fix the warning is to + * get an adapter that supports hardware + * time stamps. We'll just fall back + * on the standard host time stamps. + */ + *status = PCAP_WARNING_TSTAMP_TYPE_NOTSUP; + break; + + default: + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "SIOCSHWTSTAMP failed: %s", + pcap_strerror(errno)); + *status = PCAP_ERROR; + return -1; + } + } else { + /* + * Well, that worked. Now specify the type of + * hardware time stamp we want for this + * socket. + */ + if (handle->opt.tstamp_type == PCAP_TSTAMP_ADAPTER) { + /* + * Hardware timestamp, synchronized + * with the system clock. + */ + timesource = SOF_TIMESTAMPING_SYS_HARDWARE; + } else { + /* + * PCAP_TSTAMP_ADAPTER_UNSYNCED - hardware + * timestamp, not synchronized with the + * system clock. + */ + timesource = SOF_TIMESTAMPING_RAW_HARDWARE; + } + if (setsockopt(handle->fd, SOL_PACKET, PACKET_TIMESTAMP, + (void *)×ource, sizeof(timesource))) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't set PACKET_TIMESTAMP: %s", + pcap_strerror(errno)); + *status = PCAP_ERROR; + return -1; + } + } + } +#endif /* HAVE_LINUX_NET_TSTAMP_H && PACKET_TIMESTAMP */ /* ask the kernel to create the ring */ retry: + req.tp_block_nr = req.tp_frame_nr / frames_per_block; + + /* req.tp_frame_nr is requested to match frames_per_block*req.tp_block_nr */ + req.tp_frame_nr = req.tp_block_nr * frames_per_block; + if (setsockopt(handle->fd, SOL_PACKET, PACKET_RX_RING, (void *) &req, sizeof(req))) { - /* try to reduce requested ring size to prevent memory failure */ if ((errno == ENOMEM) && (req.tp_block_nr > 1)) { - req.tp_frame_nr >>= 1; - req.tp_block_nr = req.tp_frame_nr/frames_per_block; + /* + * Memory failure; try to reduce the requested ring + * size. + * + * We used to reduce this by half -- do 5% instead. + * That may result in more iterations and a longer + * startup, but the user will be much happier with + * the resulting buffer size. + */ + if (req.tp_frame_nr < 20) + req.tp_frame_nr -= 1; + else + req.tp_frame_nr -= req.tp_frame_nr/20; goto retry; } if (errno == ENOPROTOOPT) { @@ -2422,19 +3472,21 @@ retry: snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can't create rx ring on packet socket: %s", pcap_strerror(errno)); + *status = PCAP_ERROR; return -1; } /* memory map the rx ring */ - ringsize = req.tp_block_nr * req.tp_block_size; - handle->bp = mmap(0, ringsize, PROT_READ| PROT_WRITE, MAP_SHARED, - handle->fd, 0); - if (handle->bp == MAP_FAILED) { + handle->md.mmapbuflen = req.tp_block_nr * req.tp_block_size; + handle->md.mmapbuf = mmap(0, handle->md.mmapbuflen, + PROT_READ|PROT_WRITE, MAP_SHARED, handle->fd, 0); + if (handle->md.mmapbuf == MAP_FAILED) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can't mmap rx ring: %s", pcap_strerror(errno)); /* clear the allocated ring on error*/ destroy_ring(handle); + *status = PCAP_ERROR; return -1; } @@ -2447,13 +3499,14 @@ retry: pcap_strerror(errno)); destroy_ring(handle); + *status = PCAP_ERROR; return -1; } /* fill the header ring with proper frame ptr*/ handle->offset = 0; for (i=0; ibp[i*req.tp_block_size]; + void *base = &handle->md.mmapbuf[i*req.tp_block_size]; for (j=0; joffset) { RING_GET_FRAME(handle) = base; base += req.tp_frame_size; @@ -2476,21 +3529,49 @@ destroy_ring(pcap_t *handle) (void *) &req, sizeof(req)); /* if ring is mapped, unmap it*/ - if (handle->bp) { - /* need to re-compute the ring size */ - unsigned frames_per_block, block_size; - compute_ring_block(handle->bufsize, &block_size, &frames_per_block); - - /* do not perform sanity check here: we can't recover any error */ - munmap(handle->bp, block_size * handle->cc / frames_per_block); - handle->bp = 0; + if (handle->md.mmapbuf) { + /* do not test for mmap failure, as we can't recover from any error */ + munmap(handle->md.mmapbuf, handle->md.mmapbuflen); + handle->md.mmapbuf = NULL; } } +/* + * Special one-shot callback, used for pcap_next() and pcap_next_ex(), + * for Linux mmapped capture. + * + * The problem is that pcap_next() and pcap_next_ex() expect the packet + * data handed to the callback to be valid after the callback returns, + * but pcap_read_linux_mmap() has to release that packet as soon as + * the callback returns (otherwise, the kernel thinks there's still + * at least one unprocessed packet available in the ring, so a select() + * will immediately return indicating that there's data to process), so, + * in the callback, we have to make a copy of the packet. + * + * Yes, this means that, if the capture is using the ring buffer, using + * pcap_next() or pcap_next_ex() requires more copies than using + * pcap_loop() or pcap_dispatch(). If that bothers you, don't use + * pcap_next() or pcap_next_ex(). + */ +static void +pcap_oneshot_mmap(u_char *user, const struct pcap_pkthdr *h, + const u_char *bytes) +{ + struct oneshot_userdata *sp = (struct oneshot_userdata *)user; + + *sp->hdr = *h; + memcpy(sp->pd->md.oneshot_buffer, bytes, h->caplen); + *sp->pkt = sp->pd->md.oneshot_buffer; +} + static void pcap_cleanup_linux_mmap( pcap_t *handle ) { destroy_ring(handle); + if (handle->md.oneshot_buffer != NULL) { + free(handle->md.oneshot_buffer); + handle->md.oneshot_buffer = NULL; + } pcap_cleanup_linux(handle); } @@ -2508,11 +3589,26 @@ pcap_setnonblock_mmap(pcap_t *p, int nonblock, char *errbuf) /* map each value to the corresponding 2's complement, to * preserve the timeout value provided with pcap_set_timeout */ if (nonblock) { - if (p->md.timeout > 0) + if (p->md.timeout >= 0) { + /* + * Timeout is non-negative, so we're not already + * in non-blocking mode; set it to the 2's + * complement, to make it negative, as an + * indication that we're in non-blocking mode. + */ p->md.timeout = p->md.timeout*-1 - 1; - } else - if (p->md.timeout < 0) + } + } else { + if (p->md.timeout < 0) { + /* + * Timeout is negative, so we're not already + * in blocking mode; reverse the previous + * operation, to make the timeout non-negative + * again. + */ p->md.timeout = (p->md.timeout+1)*-1; + } + } return 0; } @@ -2539,53 +3635,95 @@ pcap_get_ring_frame(pcap_t *handle, int status) return h.raw; } -static inline void -pcap_release_previous_ring_frame(pcap_t *handle) -{ - if (handle->md.prev_pkt.raw != NULL) { - switch (handle->md.tp_version) { - case TPACKET_V1: - handle->md.prev_pkt.h1->tp_status = TP_STATUS_KERNEL; - break; -#ifdef HAVE_TPACKET2 - case TPACKET_V2: - handle->md.prev_pkt.h2->tp_status = TP_STATUS_KERNEL; - break; +#ifndef POLLRDHUP +#define POLLRDHUP 0 #endif - } - handle->md.prev_pkt.raw = NULL; - } -} static int pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) { + int timeout; int pkts = 0; + char c; /* wait for frames availability.*/ - if ((handle->md.timeout >= 0) && - !pcap_get_ring_frame(handle, TP_STATUS_USER)) { + if (!pcap_get_ring_frame(handle, TP_STATUS_USER)) { struct pollfd pollinfo; int ret; pollinfo.fd = handle->fd; pollinfo.events = POLLIN; + if (handle->md.timeout == 0) + timeout = -1; /* block forever */ + else if (handle->md.timeout > 0) + timeout = handle->md.timeout; /* block for that amount of time */ + else + timeout = 0; /* non-blocking mode - poll to pick up errors */ do { - /* poll() requires a negative timeout to wait forever */ - ret = poll(&pollinfo, 1, (handle->md.timeout > 0)? - handle->md.timeout: -1); - if ((ret < 0) && (errno != EINTR)) { + ret = poll(&pollinfo, 1, timeout); + if (ret < 0 && errno != EINTR) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "can't poll on packet socket fd %d: %d-%s", - handle->fd, errno, pcap_strerror(errno)); - return -1; - } + "can't poll on packet socket: %s", + pcap_strerror(errno)); + return PCAP_ERROR; + } else if (ret > 0 && + (pollinfo.revents & (POLLHUP|POLLRDHUP|POLLERR|POLLNVAL))) { + /* + * There's some indication other than + * "you can read on this descriptor" on + * the descriptor. + */ + if (pollinfo.revents & (POLLHUP | POLLRDHUP)) { + snprintf(handle->errbuf, + PCAP_ERRBUF_SIZE, + "Hangup on packet socket"); + return PCAP_ERROR; + } + if (pollinfo.revents & POLLERR) { + /* + * A recv() will give us the + * actual error code. + * + * XXX - make the socket non-blocking? + */ + if (recv(handle->fd, &c, sizeof c, + MSG_PEEK) != -1) + continue; /* what, no error? */ + if (errno == ENETDOWN) { + /* + * The device on which we're + * capturing went away. + * + * XXX - we should really return + * PCAP_ERROR_IFACE_NOT_UP, + * but pcap_dispatch() etc. + * aren't defined to return + * that. + */ + snprintf(handle->errbuf, + PCAP_ERRBUF_SIZE, + "The interface went down"); + } else { + snprintf(handle->errbuf, + PCAP_ERRBUF_SIZE, + "Error condition on packet socket: %s", + strerror(errno)); + } + return PCAP_ERROR; + } + if (pollinfo.revents & POLLNVAL) { + snprintf(handle->errbuf, + PCAP_ERRBUF_SIZE, + "Invalid polling request on packet socket"); + return PCAP_ERROR; + } + } /* check for break loop condition on interrupted syscall*/ if (handle->break_loop) { handle->break_loop = 0; - return -2; + return PCAP_ERROR_BREAK; } } while (ret < 0); } @@ -2604,44 +3742,10 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, unsigned int tp_sec; unsigned int tp_usec; - /* - * Check for break loop condition; a callback might have - * set it. - */ - if (handle->break_loop) { - handle->break_loop = 0; - return -2; - } - h.raw = pcap_get_ring_frame(handle, TP_STATUS_USER); if (!h.raw) break; - /* - * We have a packet; release the previous packet, - * if any. - * - * Libpcap has never guaranteed that, if we get a - * packet from the underlying packet capture - * mechanism, the data passed to callbacks for - * any previous packets is still valid. It did - * implicitly guarantee that the data will still - * be available after the callback returns, by - * virtue of implementing pcap_next() by calling - * pcap_dispatch() with a count of 1 and a callback - * that fills in a structure with a pointer to - * the packet data, meaning that pointer is - * expected to point to valid data after the - * callback returns and pcap_next() returns, - * so we can't release the packet when the - * callback returns. - * - * Therefore, we remember the packet that - * needs to be released after handing it - * to the callback, and release it up here. - */ - pcap_release_previous_ring_frame(handle); - switch (handle->md.tp_version) { case TPACKET_V1: tp_len = h.h1->tp_len; @@ -2786,27 +3890,42 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, } #endif + /* + * The only way to tell the kernel to cut off the + * packet at a snapshot length is with a filter program; + * if there's no filter program, the kernel won't cut + * the packet off. + * + * Trim the snapshot length to be no longer than the + * specified snapshot length. + */ + if (pcaphdr.caplen > handle->snapshot) + pcaphdr.caplen = handle->snapshot; + /* pass the packet to the user */ pkts++; callback(user, &pcaphdr, bp); handle->md.packets_read++; skip: - /* - * As per the comment above, we can't yet release this - * packet, even though the callback has returned, as - * some users of pcap_loop() and pcap_dispatch() - such - * as pcap_next() and pcap_next_ex() - expect the packet - * to be available until the next pcap_dispatch() call. - */ - handle->md.prev_pkt = h; + /* next packet */ + switch (handle->md.tp_version) { + case TPACKET_V1: + h.h1->tp_status = TP_STATUS_KERNEL; + break; +#ifdef HAVE_TPACKET2 + case TPACKET_V2: + h.h2->tp_status = TP_STATUS_KERNEL; + break; +#endif + } if (++handle->offset >= handle->cc) handle->offset = 0; /* check for break loop condition*/ if (handle->break_loop) { handle->break_loop = 0; - return -2; + return PCAP_ERROR_BREAK; } } return pkts; @@ -2816,7 +3935,15 @@ static int pcap_setfilter_linux_mmap(pcap_t *handle, struct bpf_program *filter) { int n, offset; - int ret = pcap_setfilter_linux(handle, filter); + int ret; + + /* + * Don't rewrite "ret" instructions; we don't need to, as + * we're not reading packets with recvmsg(), and we don't + * want to, as, by not rewriting them, the kernel can avoid + * copying extra data. + */ + ret = pcap_setfilter_linux_common(handle, filter, 1); if (ret < 0) return ret; @@ -2930,207 +4057,6 @@ iface_bind(int fd, int ifindex, char *ebuf) return 1; } -#ifdef HAVE_LIBNL -/* - * - * If interface {if} is a mac80211 driver, the file - * /sys/class/net/{if}/phy80211 is a symlink to - * /sys/class/ieee80211/{phydev}, for some {phydev}. - * - * On Fedora 9, with a 2.6.26.3-29 kernel, my Zydas stick, at - * least, has a "wmaster0" device and a "wlan0" device; the - * latter is the one with the IP address. Both show up in - * "tcpdump -D" output. Capturing on the wmaster0 device - * captures with 802.11 headers. - * - * airmon-ng searches through /sys/class/net for devices named - * monN, starting with mon0; as soon as one *doesn't* exist, - * it chooses that as the monitor device name. If the "iw" - * command exists, it does "iw dev {if} interface add {monif} - * type monitor", where {monif} is the monitor device. It - * then (sigh) sleeps .1 second, and then configures the - * device up. Otherwise, if /sys/class/ieee80211/{phydev}/add_iface - * is a file, it writes {mondev}, without a newline, to that file, - * and again (sigh) sleeps .1 second, and then iwconfig's that - * device into monitor mode and configures it up. Otherwise, - * you can't do monitor mode. - * - * All these devices are "glued" together by having the - * /sys/class/net/{device}/phy80211 links pointing to the same - * place, so, given a wmaster, wlan, or mon device, you can - * find the other devices by looking for devices with - * the same phy80211 link. - * - * To turn monitor mode off, delete the monitor interface, - * either with "iw dev {monif} interface del" or by sending - * {monif}, with no NL, down /sys/class/ieee80211/{phydev}/remove_iface - * - * Note: if you try to create a monitor device named "monN", and - * there's already a "monN" device, it fails, as least with - * the netlink interface (which is what iw uses), with a return - * value of -ENFILE. (Return values are negative errnos.) We - * could probably use that to find an unused device. - * - * Yes, you can have multiple monitor devices for a given - * physical device. -*/ - -/* - * Is this a mac80211 device? If so, fill in the physical device path and - * return 1; if not, return 0. On an error, fill in handle->errbuf and - * return PCAP_ERROR. - */ -static int -get_mac80211_phydev(pcap_t *handle, const char *device, char *phydev_path, - size_t phydev_max_pathlen) -{ - char *pathstr; - ssize_t bytes_read; - - /* - * Generate the path string for the symlink to the physical device. - */ - if (asprintf(&pathstr, "/sys/class/net/%s/phy80211", device) == -1) { - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: Can't generate path name string for /sys/class/net device", - device); - return PCAP_ERROR; - } - bytes_read = readlink(pathstr, phydev_path, phydev_max_pathlen); - if (bytes_read == -1) { - if (errno == ENOENT || errno == EINVAL) { - /* - * Doesn't exist, or not a symlink; assume that - * means it's not a mac80211 device. - */ - free(pathstr); - return 0; - } - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: Can't readlink %s: %s", device, pathstr, - strerror(errno)); - free(pathstr); - return PCAP_ERROR; - } - free(pathstr); - phydev_path[bytes_read] = '\0'; - return 1; -} - -static int -enter_rfmon_mode_mac80211(pcap_t *handle, int sock_fd, const char *device) -{ - int ret; - char phydev_path[PATH_MAX+1]; - struct nl80211_state nlstate; - struct ifreq ifr; - u_int n; - - /* - * Is this a mac80211 device? - */ - ret = get_mac80211_phydev(handle, device, phydev_path, PATH_MAX); - if (ret < 0) - return ret; /* error */ - if (ret == 0) - return 0; /* no error, but not mac80211 device */ - - /* - * XXX - is this already a monN device? - * If so, we're done. - * Is that determined by old Wireless Extensions ioctls? - */ - - /* - * OK, it's apparently a mac80211 device. - * Try to find an unused monN device for it. - */ - ret = nl80211_init(handle, &nlstate, device); - if (ret != 0) - return ret; - for (n = 0; n < UINT_MAX; n++) { - /* - * Try mon{n}. - */ - char mondevice[3+10+1]; /* mon{UINT_MAX}\0 */ - - snprintf(mondevice, sizeof mondevice, "mon%u", n); - ret = add_mon_if(handle, sock_fd, &nlstate, device, mondevice); - if (ret == 1) { - handle->md.mondevice = strdup(mondevice); - goto added; - } - if (ret < 0) { - /* - * Hard failure. Just return ret; handle->errbuf - * has already been set. - */ - nl80211_cleanup(&nlstate); - return ret; - } - } - - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: No free monN interfaces", device); - nl80211_cleanup(&nlstate); - return PCAP_ERROR; - -added: - -#if 0 - /* - * Sleep for .1 seconds. - */ - delay.tv_sec = 0; - delay.tv_nsec = 500000000; - nanosleep(&delay, NULL); -#endif - - /* - * Now configure the monitor interface up. - */ - memset(&ifr, 0, sizeof(ifr)); - strncpy(ifr.ifr_name, handle->md.mondevice, sizeof(ifr.ifr_name)); - if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) == -1) { - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: Can't get flags for %s: %s", device, - handle->md.mondevice, strerror(errno)); - del_mon_if(handle, sock_fd, &nlstate, device, - handle->md.mondevice); - nl80211_cleanup(&nlstate); - return PCAP_ERROR; - } - ifr.ifr_flags |= IFF_UP|IFF_RUNNING; - if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) { - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "%s: Can't set flags for %s: %s", device, - handle->md.mondevice, strerror(errno)); - del_mon_if(handle, sock_fd, &nlstate, device, - handle->md.mondevice); - nl80211_cleanup(&nlstate); - return PCAP_ERROR; - } - - /* - * Success. Clean up the libnl state. - */ - nl80211_cleanup(&nlstate); - - /* - * Note that we have to delete the monitor device when we close - * the handle. - */ - handle->md.must_do_on_close |= MUST_DELETE_MONIF; - - /* - * Add this to the list of pcaps to close when we exit. - */ - pcap_add_to_pcaps_to_close(handle); - - return 1; -} -#endif /* HAVE_LIBNL */ - #ifdef IW_MODE_MONITOR /* * Check whether the device supports the Wireless Extensions. @@ -3273,7 +4199,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) strncpy(ireq.ifr_ifrn.ifrn_name, device, sizeof ireq.ifr_ifrn.ifrn_name); ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; - ireq.u.data.pointer = args; + ireq.u.data.pointer = (void *)args; ireq.u.data.length = 0; ireq.u.data.flags = 0; if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) != -1) { @@ -3303,7 +4229,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) "malloc: %s", pcap_strerror(errno)); return PCAP_ERROR; } - ireq.u.data.pointer = priv; + ireq.u.data.pointer = (void *)priv; if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) == -1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno)); @@ -3777,6 +4703,97 @@ enter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device) return 0; } +/* + * Find out if we have any form of fragmentation/reassembly offloading. + */ +#ifdef SIOCETHTOOL +static int +iface_ethtool_ioctl(pcap_t *handle, int cmd, const char *cmdname) +{ + struct ifreq ifr; + struct ethtool_value eval; + + memset(&ifr, 0, sizeof(ifr)); + strncpy(ifr.ifr_name, handle->opt.source, sizeof(ifr.ifr_name)); + eval.cmd = cmd; + ifr.ifr_data = (caddr_t)&eval; + if (ioctl(handle->fd, SIOCETHTOOL, &ifr) == -1) { + if (errno == EOPNOTSUPP) { + /* + * OK, let's just return 0, which, in our + * case, either means "no, what we're asking + * about is not enabled" or "all the flags + * are clear (i.e., nothing is enabled)". + */ + return 0; + } + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: SIOETHTOOL(%s) ioctl failed: %s", handle->opt.source, + cmdname, strerror(errno)); + return -1; + } + return eval.data; +} + +static int +iface_get_offload(pcap_t *handle) +{ + int ret; + + ret = iface_ethtool_ioctl(handle, ETHTOOL_GTSO, "ETHTOOL_GTSO"); + if (ret == -1) + return -1; + if (ret) + return 1; /* TCP segmentation offloading on */ + + ret = iface_ethtool_ioctl(handle, ETHTOOL_GUFO, "ETHTOOL_GUFO"); + if (ret == -1) + return -1; + if (ret) + return 1; /* UDP fragmentation offloading on */ + + /* + * XXX - will this cause large unsegmented packets to be + * handed to PF_PACKET sockets on transmission? If not, + * this need not be checked. + */ + ret = iface_ethtool_ioctl(handle, ETHTOOL_GGSO, "ETHTOOL_GGSO"); + if (ret == -1) + return -1; + if (ret) + return 1; /* generic segmentation offloading on */ + + ret = iface_ethtool_ioctl(handle, ETHTOOL_GFLAGS, "ETHTOOL_GFLAGS"); + if (ret == -1) + return -1; + if (ret & ETH_FLAG_LRO) + return 1; /* large receive offloading on */ + + /* + * XXX - will this cause large reassembled packets to be + * handed to PF_PACKET sockets on receipt? If not, + * this need not be checked. + */ + ret = iface_ethtool_ioctl(handle, ETHTOOL_GGRO, "ETHTOOL_GGRO"); + if (ret == -1) + return -1; + if (ret) + return 1; /* generic (large) receive offloading on */ + + return 0; +} +#else /* SIOCETHTOOL */ +static int +iface_get_offload(pcap_t *handle _U_) +{ + /* + * XXX - do we need to get this information if we don't + * have the ethtool ioctls? If so, how do we do that? + */ + return 0; +} +#endif /* SIOCETHTOOL */ + #endif /* HAVE_PF_PACKET_SOCKETS */ /* ===== Functions to interface to the older kernels ================== */ @@ -4051,7 +5068,7 @@ iface_get_arptype(int fd, const char *device, char *ebuf) #ifdef SO_ATTACH_FILTER static int -fix_program(pcap_t *handle, struct sock_fprog *fcode) +fix_program(pcap_t *handle, struct sock_fprog *fcode, int is_mmapped) { size_t prog_size; register int i; @@ -4084,26 +5101,33 @@ fix_program(pcap_t *handle, struct sock_fprog *fcode) case BPF_RET: /* - * It's a return instruction; is the snapshot - * length a constant, rather than the contents - * of the accumulator? + * It's a return instruction; are we capturing + * in memory-mapped mode? */ - if (BPF_MODE(p->code) == BPF_K) { + if (!is_mmapped) { /* - * Yes - if the value to be returned, - * i.e. the snapshot length, is anything - * other than 0, make it 65535, so that - * the packet is truncated by "recvfrom()", - * not by the filter. - * - * XXX - there's nothing we can easily do - * if it's getting the value from the - * accumulator; we'd have to insert - * code to force non-zero values to be - * 65535. + * No; is the snapshot length a constant, + * rather than the contents of the + * accumulator? */ - if (p->k != 0) - p->k = 65535; + if (BPF_MODE(p->code) == BPF_K) { + /* + * Yes - if the value to be returned, + * i.e. the snapshot length, is + * anything other than 0, make it + * 65535, so that the packet is + * truncated by "recvfrom()", + * not by the filter. + * + * XXX - there's nothing we can + * easily do if it's getting the + * value from the accumulator; we'd + * have to insert code to force + * non-zero values to be 65535. + */ + if (p->k != 0) + p->k = 65535; + } } break;