X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/34e950492a8b40673297d0888fafc4f94689cd29..ade794238b623a81e2585d1c2073a3bececa10ae:/pcap-linux.c diff --git a/pcap-linux.c b/pcap-linux.c index 5aced44b..deabbc4a 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? @@ -168,6 +175,10 @@ 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 +187,10 @@ 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 +300,7 @@ 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 *); @@ -305,7 +320,7 @@ union thdr { #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 *); @@ -370,12 +385,25 @@ 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); @@ -388,52 +416,73 @@ 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; } #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. + * 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. */ /* @@ -478,8 +527,37 @@ get_mac80211_phydev(pcap_t *handle, const char *device, char *phydev_path, return 1; } +#ifndef HAVE_LIBNL_2_x +/* 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); +} + +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; }; @@ -487,23 +565,26 @@ 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, strerror(-err)); goto out_handle_destroy; } @@ -519,7 +600,7 @@ 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; } @@ -528,7 +609,7 @@ 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 @@ -556,7 +637,7 @@ 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) { if (err == -ENFILE) { /* @@ -577,7 +658,7 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, return PCAP_ERROR; } } - err = nl_wait_for_ack(state->nl_handle); + err = nl_wait_for_ack(state->nl_sock); if (err < 0) { if (err == -ENFILE) { /* @@ -636,7 +717,7 @@ del_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, 0, NL80211_CMD_DEL_INTERFACE, 0); NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex); - err = nl_send_auto_complete(state->nl_handle, msg); + err = nl_send_auto_complete(state->nl_sock, msg); if (err < 0) { if (err == -ENFILE) { /* @@ -657,7 +738,7 @@ del_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, return PCAP_ERROR; } } - err = nl_wait_for_ack(state->nl_handle); + err = nl_wait_for_ack(state->nl_sock); if (err < 0) { if (err == -ENFILE) { /* @@ -880,6 +961,8 @@ pcap_can_set_rfmon_linux(pcap_t *handle) } 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; } @@ -888,6 +971,67 @@ pcap_can_set_rfmon_linux(pcap_t *handle) 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) +{ + 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; + + 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; + + /* 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); + + break; + } + } + + fclose(file); + return dropped_pkts; +} + + /* * With older kernels promiscuous mode is kind of interesting because we * have to reset the interface before exiting. The problem can't really @@ -1063,6 +1207,14 @@ 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 @@ -1073,34 +1225,46 @@ 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; } } @@ -1114,18 +1278,12 @@ 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. @@ -1261,12 +1419,12 @@ 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) @@ -1278,17 +1436,32 @@ 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; } } @@ -1446,7 +1619,7 @@ 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; @@ -1561,6 +1734,18 @@ 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. @@ -1581,6 +1766,8 @@ 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. @@ -1644,19 +1831,299 @@ pcap_stats_linux(pcap_t *handle, struct pcap_stat *stats) * * "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. + * 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)); + 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)); + 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); +} + /* * Description string for the "any" device. */ @@ -1665,25 +2132,66 @@ 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 @@ -1858,7 +2366,6 @@ 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 @@ -1966,6 +2473,12 @@ 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 */ @@ -2199,6 +2712,13 @@ 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; @@ -2500,10 +3020,22 @@ 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; /* @@ -2515,7 +3047,8 @@ activate_mmap(pcap_t *handle) snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can't allocate oneshot buffer: %s", pcap_strerror(errno)); - return PCAP_ERROR; + *status = PCAP_ERROR; + return -1; } if (handle->opt.buffer_size == 0) { @@ -2523,20 +3056,38 @@ activate_mmap(pcap_t *handle) handle->opt.buffer_size = 2*1024*1024; } ret = prepare_tpacket_socket(handle); - if (ret != 1) { + if (ret == -1) { free(handle->md.oneshot_buffer); + *status = PCAP_ERROR; return ret; } - ret = create_ring(handle); - if (ret != 1) { + 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 ret; + 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; @@ -2545,12 +3096,21 @@ activate_mmap(pcap_t *handle) 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) { @@ -2602,12 +3162,29 @@ prepare_tpacket_socket(pcap_t *handle) return 1; } +/* + * 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) +create_ring(pcap_t *handle, int *status) { unsigned i, j, frames_per_block; struct tpacket_req req; + /* + * Start out assuming no warnings or errors. + */ + *status = 0; + /* 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). @@ -2628,6 +3205,109 @@ create_ring(pcap_t *handle) frames_per_block = req.tp_block_size/req.tp_frame_size; + /* + * 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; + + /* + * 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; + + 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; @@ -2662,6 +3342,7 @@ retry: snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can't create rx ring on packet socket: %s", pcap_strerror(errno)); + *status = PCAP_ERROR; return -1; } @@ -2675,6 +3356,7 @@ retry: /* clear the allocated ring on error*/ destroy_ring(handle); + *status = PCAP_ERROR; return -1; } @@ -2687,6 +3369,7 @@ retry: pcap_strerror(errno)); destroy_ring(handle); + *status = PCAP_ERROR; return -1; } @@ -2744,8 +3427,7 @@ static void pcap_oneshot_mmap(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes) { - struct pkt_for_oneshot *sp = (struct pkt_for_oneshot *)user; - bpf_u_int32 copylen; + struct oneshot_userdata *sp = (struct oneshot_userdata *)user; *sp->hdr = *h; memcpy(sp->pd->md.oneshot_buffer, bytes, h->caplen); @@ -2823,35 +3505,95 @@ pcap_get_ring_frame(pcap_t *handle, int status) return h.raw; } +#ifndef POLLRDHUP +#define POLLRDHUP 0 +#endif + 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); } @@ -3027,8 +3769,8 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, * Trim the snapshot length to be no longer than the * specified snapshot length. */ - if (pcaphdr.snaplen > handle->snapshot) - pcaphdr.snaplen = handle->snapshot; + if (pcaphdr.caplen > handle->snapshot) + pcaphdr.caplen = handle->snapshot; /* pass the packet to the user */ pkts++; @@ -3053,7 +3795,7 @@ skip: /* check for break loop condition*/ if (handle->break_loop) { handle->break_loop = 0; - return -2; + return PCAP_ERROR_BREAK; } } return pkts;