X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/d9b420231a4428234f666eb6c44a4dea6f1f2d71..6de2dedb10df2f18db55e41f59b47824de314279:/pcap-linux.c diff --git a/pcap-linux.c b/pcap-linux.c index cb805c88..de14a7ec 100644 --- a/pcap-linux.c +++ b/pcap-linux.c @@ -30,11 +30,44 @@ * based on previous works of: * Simon Patarin * Phil Wood + * + * Monitor-mode support for mac80211 includes code taken from the iw + * command; the copyright notice for that code is + * + * Copyright (c) 2007, 2008 Johannes Berg + * Copyright (c) 2007 Andy Lutomirski + * Copyright (c) 2007 Mike Kershaw + * Copyright (c) 2008 Gábor Stefanik + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. */ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.140 2008-04-04 19:37:45 guy Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.164 2008-12-14 22:00:57 guy Exp $ (LBL)"; #endif /* @@ -80,20 +113,24 @@ static const char rcsid[] _U_ = */ +#define _GNU_SOURCE + #ifdef HAVE_CONFIG_H #include "config.h" #endif #include +#include #include #include #include #include +#include #include #include #include #include -#include +#include #include #include #include @@ -104,10 +141,24 @@ static const char rcsid[] _U_ = */ #ifdef HAVE_LINUX_WIRELESS_H #include -#endif +#endif /* HAVE_LINUX_WIRELESS_H */ + +/* + * Got libnl? + */ +#ifdef HAVE_LIBNL +#include + +#include +#include +#include +#include +#include +#endif /* HAVE_LIBNL */ #include "pcap-int.h" #include "pcap/sll.h" +#include "pcap/vlan.h" #ifdef HAVE_DAG_API #include "pcap-dag.h" @@ -165,6 +216,9 @@ static const char rcsid[] _U_ = */ # ifdef PACKET_HOST # define HAVE_PF_PACKET_SOCKETS +# ifdef PACKET_AUXDATA +# define HAVE_PACKET_AUXDATA +# endif /* PACKET_AUXDATA */ # endif /* PACKET_HOST */ @@ -173,6 +227,11 @@ static const char rcsid[] _U_ = * uses many ring related structs and macros */ # ifdef TPACKET_HDRLEN # define HAVE_PACKET_RING +# ifdef TPACKET2_HDRLEN +# define HAVE_TPACKET2 +# else +# define TPACKET_V1 0 +# endif /* TPACKET2_HDRLEN */ # endif /* TPACKET_HDRLEN */ #endif /* PF_PACKET */ @@ -234,18 +293,27 @@ static int pcap_inject_linux(pcap_t *, const void *, size_t); static int pcap_stats_linux(pcap_t *, struct pcap_stat *); static int pcap_setfilter_linux(pcap_t *, struct bpf_program *); static int pcap_setdirection_linux(pcap_t *, pcap_direction_t); -static void pcap_close_linux(pcap_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) (((struct tpacket_hdr**)h->buffer)[h->offset]) +#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 void pcap_close_linux_mmap(pcap_t *); +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 /* @@ -258,14 +326,17 @@ 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 static int iface_bind(int fd, int ifindex, char *ebuf); -static int has_wext(int sock_fd, const char *device); -static int enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, +#ifdef IW_MODE_MONITOR +static int has_wext(int sock_fd, const char *device, char *ebuf); +#endif /* IW_MODE_MONITOR */ +static int enter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device); -#endif +#endif /* HAVE_PF_PACKET_SOCKETS */ 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); @@ -281,6 +352,12 @@ pcap_create(const char *device, char *ebuf) { pcap_t *handle; + /* + * A null device name is equivalent to the "any" device. + */ + if (device == NULL) + device = "any"; + #ifdef HAVE_DAG_API if (strstr(device, "dag")) { return dag_create(device, ebuf); @@ -300,7 +377,7 @@ pcap_create(const char *device, char *ebuf) #endif #ifdef PCAP_SUPPORT_USB - if (strstr(device, "usb")) { + if (strstr(device, "usbmon")) { return usb_create(device, ebuf); } #endif @@ -314,22 +391,462 @@ pcap_create(const char *device, char *ebuf) 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. +*/ + +/* + * 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; +} + +struct nl80211_state { + struct nl_handle *nl_handle; + struct nl_cache *nl_cache; + struct genl_family *nl80211; +}; + +static int +nl80211_init(pcap_t *handle, struct nl80211_state *state, const char *device) +{ + state->nl_handle = nl_handle_alloc(); + if (!state->nl_handle) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: failed to allocate netlink handle", device); + return PCAP_ERROR; + } + + if (genl_connect(state->nl_handle)) { + 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) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: failed to allocate generic netlink cache", device); + goto out_handle_destroy; + } + + state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211"); + if (!state->nl80211) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: nl80211 not found", device); + goto out_cache_free; + } + + return 0; + +out_cache_free: + nl_cache_free(state->nl_cache); +out_handle_destroy: + nl_handle_destroy(state->nl_handle); + return PCAP_ERROR; +} + +static void +nl80211_cleanup(struct nl80211_state *state) +{ + genl_family_put(state->nl80211); + nl_cache_free(state->nl_cache); + nl_handle_destroy(state->nl_handle); +} + +static int +add_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, device, 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_NEW_INTERFACE, 0); + NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex); + 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); + 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 adding %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; + } + } + + /* + * Success. + */ + nlmsg_free(msg); + return 1; + +nla_put_failure: + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "%s: nl_put failed adding %s interface", + device, mondevice); + nlmsg_free(msg); + return PCAP_ERROR; +} + +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_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; + } + } + + /* + * 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 *p) +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 (p->opt.source == NULL) { + if (strcmp(handle->opt.source, "any") == 0) { /* - * This is equivalent to the "any" device, and we don't - * support monitor mode on it. + * 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 @@ -343,7 +860,7 @@ pcap_can_set_rfmon_linux(pcap_t *p) */ sock_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (sock_fd == -1) { - (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + (void)snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "socket: %s", pcap_strerror(errno)); return PCAP_ERROR; } @@ -351,7 +868,7 @@ pcap_can_set_rfmon_linux(pcap_t *p) /* * Attempt to get the current mode. */ - strncpy(ireq.ifr_ifrn.ifrn_name, p->opt.source, + 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) { @@ -383,19 +900,23 @@ pcap_can_set_rfmon_linux(pcap_t *p) * Even with newer kernels, we have the same issue with rfmon mode. */ -static void pcap_close_linux( pcap_t *handle ) +static void pcap_cleanup_linux( pcap_t *handle ) { struct ifreq ifr; +#ifdef HAVE_LIBNL + struct nl80211_state nlstate; + int ret; +#endif /* HAVE_LIBNL */ #ifdef IW_MODE_MONITOR struct iwreq ireq; -#endif +#endif /* IW_MODE_MONITOR */ - if (handle->md.must_clear != 0) { + if (handle->md.must_do_on_close != 0) { /* * There's something we have to do when closing this * pcap_t. */ - if (handle->md.must_clear & MUST_CLEAR_PROMISC) { + if (handle->md.must_do_on_close & MUST_CLEAR_PROMISC) { /* * We put the interface into promiscuous mode; * take it out of promiscuous mode. @@ -433,8 +954,25 @@ static void pcap_close_linux( pcap_t *handle ) } } +#ifdef HAVE_LIBNL + if (handle->md.must_do_on_close & MUST_DELETE_MONIF) { + ret = nl80211_init(handle, &nlstate, handle->md.device); + if (ret >= 0) { + ret = del_mon_if(handle, handle->fd, &nlstate, + handle->md.device, handle->md.mondevice); + nl80211_cleanup(&nlstate); + } + if (ret < 0) { + fprintf(stderr, + "Can't delete monitor interface %s (%s).\n" + "Please delete manually.\n", + handle->md.mondevice, handle->errbuf); + } + } +#endif /* HAVE_LIBNL */ + #ifdef IW_MODE_MONITOR - if (handle->md.must_clear & MUST_CLEAR_RFMON) { + if (handle->md.must_do_on_close & MUST_CLEAR_RFMON) { /* * We put the interface into rfmon mode; * take it out of rfmon mode. @@ -458,7 +996,7 @@ static void pcap_close_linux( pcap_t *handle ) strerror(errno)); } } -#endif +#endif /* IW_MODE_MONITOR */ /* * Take this pcap out of the list of pcaps for which we @@ -467,11 +1005,15 @@ static void pcap_close_linux( pcap_t *handle ) pcap_remove_from_pcaps_to_close(handle); } + if (handle->md.mondevice != NULL) { + free(handle->md.mondevice); + handle->md.mondevice = NULL; + } if (handle->md.device != NULL) { free(handle->md.device); handle->md.device = NULL; } - pcap_close_common(handle); + pcap_cleanup_live_common(handle); } /* @@ -486,8 +1028,7 @@ static int pcap_activate_linux(pcap_t *handle) { const char *device; - int err; - int activate_ok = 0; + int status = 0; device = handle->opt.source; @@ -497,27 +1038,26 @@ pcap_activate_linux(pcap_t *handle) handle->set_datalink_op = NULL; /* can't change data link type */ handle->getnonblock_op = pcap_getnonblock_fd; handle->setnonblock_op = pcap_setnonblock_fd; - handle->close_op = pcap_close_linux; + handle->cleanup_op = pcap_cleanup_linux; handle->read_op = pcap_read_linux; handle->stats_op = pcap_stats_linux; /* - * NULL and "any" are special devices which give us the hint to - * monitor all devices. + * The "any" device is a special device which causes us not + * to bind to a particular device and thus to look at all + * devices. */ - if (!device || strcmp(device, "any") == 0) { - device = NULL; - handle->md.device = strdup("any"); + if (strcmp(device, "any") == 0) { if (handle->opt.promisc) { handle->opt.promisc = 0; /* Just a warning. */ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Promiscuous mode not supported on the \"any\" device"); + status = PCAP_WARNING_PROMISC_NOTSUP; } + } - } else - handle->md.device = strdup(device); - + handle->md.device = strdup(device); if (handle->md.device == NULL) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", pcap_strerror(errno) ); @@ -534,31 +1074,70 @@ pcap_activate_linux(pcap_t *handle) * trying both methods with the newer method preferred. */ - if ((err = activate_new(handle)) == 1) { - activate_ok = 1; + if ((status = activate_new(handle)) == 1) { /* + * Success. * Try to use memory-mapped access. */ - if (activate_mmap(handle) == 1) - return 0; /* we succeeded; nothing more to do */ + switch (activate_mmap(handle)) { + + case 1: + /* we succeeded; nothing more to do */ + return 0; + + 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. + */ + status = PCAP_ERROR; + goto fail; + } } - else if (err == 0) { + else if (status == 0) { /* Non-fatal error; try old way */ - if ((err = activate_old(handle)) == 1) - activate_ok = 1; - } - if (!activate_ok) { + if ((status = activate_old(handle)) != 1) { + /* + * Both methods to open the packet socket failed. + * Tidy up and report our failure (handle->errbuf + * is expected to be set by the functions above). + */ + goto fail; + } + } else { /* - * Both methods to open the packet socket failed. Tidy - * up and report our failure (ebuf is expected to be - * set by the functions above). + * 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 (handle->md.device != NULL) { - free(handle->md.device); - handle->md.device = NULL; + /* + * We set up the socket, but not with memory-mapped access. + */ + if (handle->opt.buffer_size != 0) { + /* + * Set the socket buffer size to the specified value. + */ + if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, + &handle->opt.buffer_size, + sizeof(handle->opt.buffer_size)) == -1) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "SO_RCVBUF: %s", pcap_strerror(errno)); + status = PCAP_ERROR; + goto fail; } - return err; } /* Allocate the buffer */ @@ -567,7 +1146,8 @@ pcap_activate_linux(pcap_t *handle) if (!handle->buffer) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); - return PCAP_ERROR; + status = PCAP_ERROR; + goto fail; } /* @@ -576,7 +1156,11 @@ pcap_activate_linux(pcap_t *handle) */ handle->selectable_fd = handle->fd; - return 0; + return status; + +fail: + pcap_cleanup_linux(handle); + return status; } /* @@ -610,7 +1194,17 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) #else struct sockaddr from; #endif +#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) + struct iovec iov; + struct msghdr msg; + struct cmsghdr *cmsg; + union { + struct cmsghdr cmsg; + char buf[CMSG_SPACE(sizeof(struct tpacket_auxdata))]; + } cmsg_buf; +#else /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ socklen_t fromlen; +#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ int packet_len, caplen; struct pcap_pkthdr pcap_header; @@ -631,9 +1225,36 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) offset = 0; #endif - /* Receive a single packet from the kernel */ - + /* + * Receive a single packet from the kernel. + * We ignore EINTR, as that might just be due to a signal + * being delivered - if the signal should interrupt the + * loop, the signal handler should call pcap_breakloop() + * to set handle->break_loop (we ignore it on other + * platforms as well). + * We also ignore ENETDOWN, so that we can continue to + * capture traffic if the interface goes down and comes + * back up again; comments in the kernel indicate that + * we'll just block waiting for packets if we try to + * receive from a socket that delivered ENETDOWN, and, + * if we're using a memory-mapped buffer, we won't even + * get notified of "network down" events. + */ bp = handle->buffer + handle->offset; + +#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) + msg.msg_name = &from; + msg.msg_namelen = sizeof(from); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = &cmsg_buf; + msg.msg_controllen = sizeof(cmsg_buf); + msg.msg_flags = 0; + + iov.iov_len = handle->bufsize - offset; + iov.iov_base = bp + offset; +#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ + do { /* * Has "pcap_breakloop()" been called? @@ -647,12 +1268,17 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) handle->break_loop = 0; return -2; } + +#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) + packet_len = recvmsg(handle->fd, &msg, MSG_TRUNC); +#else /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ fromlen = sizeof(from); packet_len = recvfrom( handle->fd, bp + offset, handle->bufsize - offset, MSG_TRUNC, (struct sockaddr *) &from, &fromlen); - } while (packet_len == -1 && errno == EINTR); +#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ + } while (packet_len == -1 && (errno == EINTR || errno == ENETDOWN)); /* Check if an error occured */ @@ -737,7 +1363,37 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) from.sll_halen); hdrp->sll_protocol = from.sll_protocol; } -#endif + +#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { + struct tpacket_auxdata *aux; + unsigned int len; + struct vlan_tag *tag; + + if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct tpacket_auxdata)) || + cmsg->cmsg_level != SOL_PACKET || + cmsg->cmsg_type != PACKET_AUXDATA) + continue; + + aux = (struct tpacket_auxdata *)CMSG_DATA(cmsg); + if (aux->tp_vlan_tci == 0) + continue; + + len = packet_len > iov.iov_len ? iov.iov_len : packet_len; + if (len < 2 * ETH_ALEN) + break; + + bp -= VLAN_TAG_LEN; + memmove(bp, bp + VLAN_TAG_LEN, 2 * ETH_ALEN); + + tag = (struct vlan_tag *)(bp + 2 * ETH_ALEN); + tag->vlan_tpid = htons(ETH_P_8021Q); + tag->vlan_tci = htons(aux->tp_vlan_tci); + + packet_len += VLAN_TAG_LEN; + } +#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ +#endif /* HAVE_PF_PACKET_SOCKETS */ /* * XXX: According to the kernel source we should get the real @@ -1039,7 +1695,8 @@ 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; @@ -1092,13 +1749,13 @@ 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: @@ -1172,6 +1829,13 @@ 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? @@ -1524,6 +2188,17 @@ static void map_arphrd_to_dlt(pcap_t *handle, int arptype, int cooked_ok) handle->linktype = DLT_LINUX_LAPD; break; +#ifndef ARPHRD_NONE +#define ARPHRD_NONE 0xFFFE +#endif + case ARPHRD_NONE: + /* + * No link-layer header; packets are just IP + * packets, so use DLT_RAW. + */ + handle->linktype = DLT_RAW; + break; + default: handle->linktype = -1; break; @@ -1543,19 +2218,24 @@ static int 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; +#ifdef HAVE_PACKET_AUXDATA + int val; +#endif int err = 0; struct packet_mreq mr; - const char* device = handle->opt.source; /* - * Open a socket with protocol family packet. If a device is - * given we try to open it in raw mode otherwise we use - * the cooked interface. + * Open a socket with protocol family packet. If the + * "any" device was specified, we open a SOCK_DGRAM + * socket for the cooked interface, otherwise we first + * try a SOCK_RAW socket for the raw interface. */ - sock_fd = device ? - socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)) - : socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL)); + sock_fd = is_any_device ? + socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL)) : + socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (sock_fd == -1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "socket: %s", @@ -1590,7 +2270,7 @@ activate_new(pcap_t *handle) * to cooked mode if we have an unknown interface type * or a type we know doesn't work well in raw mode. */ - if (device) { + if (!is_any_device) { /* Assume for now we don't need cooked mode. */ handle->md.cooked = 0; @@ -1601,7 +2281,7 @@ activate_new(pcap_t *handle) * because entering monitor mode could change * the link-layer type. */ - err = enter_rfmon_mode_wext(handle, sock_fd, device); + err = enter_rfmon_mode(handle, sock_fd, device); if (err < 0) { /* Hard failure */ close(sock_fd); @@ -1615,6 +2295,15 @@ activate_new(pcap_t *handle) close(sock_fd); return PCAP_ERROR_RFMON_NOTSUP; } + + /* + * Either monitor mode has been turned on for + * the device, or we've been given a different + * device to open for monitor mode. If we've + * been given a different device, use it. + */ + if (handle->md.mondevice != NULL) + device = handle->md.mondevice; } arptype = iface_get_arptype(sock_fd, device, handle->errbuf); if (arptype < 0) { @@ -1696,24 +2385,32 @@ activate_new(pcap_t *handle) } if ((err = iface_bind(sock_fd, handle->md.ifindex, - handle->errbuf)) < 0) { + handle->errbuf)) != 1) { close(sock_fd); - if (err == -2) - return PCAP_ERROR; + if (err < 0) + return err; else return 0; /* try old mechanism */ } } else { /* - * This is cooked mode. + * The "any" device. + */ + if (handle->opt.rfmon) { + /* + * It doesn't support monitor mode. + */ + return PCAP_ERROR_RFMON_NOTSUP; + } + + /* + * It uses cooked mode. */ handle->md.cooked = 1; handle->linktype = DLT_LINUX_SLL; /* * We're not bound to a device. - * XXX - true? Or true only if we're using - * the "any" device? * For now, we're using this as an indication * that we can't transmit; stop doing that only * if we figure out how to transmit in cooked @@ -1738,10 +2435,13 @@ activate_new(pcap_t *handle) /* * Hmm, how can we set promiscuous mode on all interfaces? - * I am not sure if that is possible at all. + * I am not sure if that is possible at all. For now, we + * silently ignore attempts to turn promiscuous mode on + * for the "any" device (so you don't have to explicitly + * disable it in programs such as tcpdump). */ - if (device && handle->opt.promisc) { + if (!is_any_device && handle->opt.promisc) { memset(&mr, 0, sizeof(mr)); mr.mr_ifindex = handle->md.ifindex; mr.mr_type = PACKET_MR_PROMISC; @@ -1754,6 +2454,20 @@ activate_new(pcap_t *handle) } } + /* Enable auxillary data if supported and reserve room for + * reconstructing VLAN headers. */ +#ifdef HAVE_PACKET_AUXDATA + val = 1; + if (setsockopt(sock_fd, SOL_PACKET, PACKET_AUXDATA, &val, + sizeof(val)) == -1 && errno != ENOPROTOOPT) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "setsockopt: %s", pcap_strerror(errno)); + close(sock_fd); + return PCAP_ERROR; + } + handle->offset += VLAN_TAG_LEN; +#endif /* HAVE_PACKET_AUXDATA */ + /* * This is a 2.2[.x] or later kernel (we know that * because we're not using a SOCK_PACKET socket - @@ -1775,7 +2489,7 @@ activate_new(pcap_t *handle) handle->bufsize = handle->snapshot; /* Save the socket FD in the pcap structure */ - handle->fd = sock_fd; + handle->fd = sock_fd; return 1; #else @@ -1792,23 +2506,43 @@ activate_mmap(pcap_t *handle) #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)); + return PCAP_ERROR; + } + 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) { + free(handle->md.oneshot_buffer); + return ret; + } ret = create_ring(handle); - if (ret == 0) + if (ret != 1) { + free(handle->md.oneshot_buffer); return ret; + } /* 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->close_op = pcap_close_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 */ @@ -1817,25 +2551,61 @@ activate_mmap(pcap_t *handle) } #ifdef HAVE_PACKET_RING - -static void -compute_ring_block(int frame_size, unsigned *block_size, unsigned *frames_per_block) +static int +prepare_tpacket_socket(pcap_t *handle) { - /* 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; +#ifdef HAVE_TPACKET2 + socklen_t len; + int val; +#endif + + handle->md.tp_version = TPACKET_V1; + handle->md.tp_hdrlen = sizeof(struct tpacket_hdr); + +#ifdef HAVE_TPACKET2 + /* Probe whether kernel supports TPACKET_V2 */ + val = TPACKET_V2; + len = sizeof(val); + if (getsockopt(handle->fd, SOL_PACKET, PACKET_HDRLEN, &val, &len) < 0) { + if (errno == ENOPROTOOPT) + return 1; /* no - just drive on */ + + /* Yes - treat as a failure. */ + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't get TPACKET_V2 header len on packet socket: %s", + pcap_strerror(errno)); + return -1; + } + handle->md.tp_hdrlen = val; - *frames_per_block = *block_size/frame_size; + val = TPACKET_V2; + if (setsockopt(handle->fd, SOL_PACKET, PACKET_VERSION, &val, + sizeof(val)) < 0) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't activate TPACKET_V2 on packet socket: %s", + pcap_strerror(errno)); + return -1; + } + handle->md.tp_version = TPACKET_V2; + + /* Reserve space for VLAN tag reconstruction */ + val = VLAN_TAG_LEN; + if (setsockopt(handle->fd, SOL_PACKET, PACKET_RESERVE, &val, + sizeof(val)) < 0) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't set up reserve on packet socket: %s", + pcap_strerror(errno)); + return -1; + } + +#endif /* HAVE_TPACKET2 */ + return 1; } static int create_ring(pcap_t *handle) { - unsigned i, j, ringsize, frames_per_block; + unsigned i, j, frames_per_block; struct tpacket_req req; /* Note that with large snapshot (say 64K) only a few frames @@ -1843,57 +2613,89 @@ create_ring(pcap_t *handle) * (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_HDRLEN); + 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; - /* 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; + /* 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. */ + req.tp_block_size = getpagesize(); + while (req.tp_block_size < req.tp_frame_size) + req.tp_block_size <<= 1; + + frames_per_block = req.tp_block_size/req.tp_frame_size; /* 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; } - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can't create rx ring on " - "packet socket %d: %d-%s", handle->fd, errno, - pcap_strerror(errno)); - return 0; + if (errno == ENOPROTOOPT) { + /* + * We don't have ring buffer support in this kernel. + */ + return 0; + } + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't create rx ring on packet socket: %s", + pcap_strerror(errno)); + 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) { - snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can't mmap rx ring: %d-%s", - errno, pcap_strerror(errno)); + 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); - return 0; + return -1; } /* allocate a ring for each frame header pointer*/ handle->cc = req.tp_frame_nr; - handle->buffer = malloc(handle->cc * sizeof(struct tpacket_hdr*)); + handle->buffer = malloc(handle->cc * sizeof(union thdr *)); if (!handle->buffer) { + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "can't allocate ring of frame headers: %s", + pcap_strerror(errno)); + destroy_ring(handle); - return 0; + 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) = (struct tpacket_hdr*) base; + RING_GET_FRAME(handle) = base; base += req.tp_frame_size; } } @@ -1914,28 +2716,51 @@ 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 the header ring is allocated, clear it*/ - if (handle->buffer) { - free(handle->buffer); - handle->buffer = 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 pkt_for_oneshot *sp = (struct pkt_for_oneshot *)user; + bpf_u_int32 copylen; + + *sp->hdr = *h; + memcpy(sp->pd->md.oneshot_buffer, bytes, h->caplen); + *sp->pkt = sp->pd->md.oneshot_buffer; +} + static void -pcap_close_linux_mmap( pcap_t *handle ) +pcap_cleanup_linux_mmap( pcap_t *handle ) { destroy_ring(handle); - pcap_close_linux(handle); + if (handle->md.oneshot_buffer != NULL) { + free(handle->md.oneshot_buffer); + handle->md.oneshot_buffer = NULL; + } + pcap_cleanup_linux(handle); } @@ -1952,14 +2777,52 @@ 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; } +static inline union thdr * +pcap_get_ring_frame(pcap_t *handle, int status) +{ + union thdr h; + + h.raw = RING_GET_FRAME(handle); + switch (handle->md.tp_version) { + case TPACKET_V1: + if (status != (h.h1->tp_status ? TP_STATUS_USER : + TP_STATUS_KERNEL)) + return NULL; + break; +#ifdef HAVE_TPACKET2 + case TPACKET_V2: + if (status != (h.h2->tp_status ? TP_STATUS_USER : + TP_STATUS_KERNEL)) + return NULL; + break; +#endif + } + return h.raw; +} + static int pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) @@ -1967,7 +2830,8 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, int pkts = 0; /* wait for frames availability.*/ - if ((handle->md.timeout >= 0) && !(RING_GET_FRAME(handle)->tp_status)) { + if ((handle->md.timeout >= 0) && + !pcap_get_ring_frame(handle, TP_STATUS_USER)) { struct pollfd pollinfo; int ret; @@ -1999,16 +2863,46 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, struct sockaddr_ll *sll; struct pcap_pkthdr pcaphdr; unsigned char *bp; - struct tpacket_hdr* thdr = RING_GET_FRAME(handle); - if (thdr->tp_status == TP_STATUS_KERNEL) + union thdr h; + unsigned int tp_len; + unsigned int tp_mac; + unsigned int tp_snaplen; + unsigned int tp_sec; + unsigned int tp_usec; + + h.raw = pcap_get_ring_frame(handle, TP_STATUS_USER); + if (!h.raw) break; + switch (handle->md.tp_version) { + case TPACKET_V1: + tp_len = h.h1->tp_len; + tp_mac = h.h1->tp_mac; + tp_snaplen = h.h1->tp_snaplen; + tp_sec = h.h1->tp_sec; + tp_usec = h.h1->tp_usec; + break; +#ifdef HAVE_TPACKET2 + case TPACKET_V2: + tp_len = h.h2->tp_len; + tp_mac = h.h2->tp_mac; + tp_snaplen = h.h2->tp_snaplen; + tp_sec = h.h2->tp_sec; + tp_usec = h.h2->tp_nsec / 1000; + break; +#endif + default: + snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "unsupported tpacket version %d", + handle->md.tp_version); + return -1; + } /* perform sanity check on internal offset. */ - if (thdr->tp_mac+thdr->tp_snaplen > handle->bufsize) { + if (tp_mac + tp_snaplen > handle->bufsize) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "corrupted frame on kernel ring mac " "offset %d + caplen %d > frame len %d", - thdr->tp_mac, thdr->tp_snaplen, handle->bufsize); + tp_mac, tp_snaplen, handle->bufsize); return -1; } @@ -2021,25 +2915,47 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, * Note: alternatively it could be possible to stop applying * the filter when the ring became empty, but it can possibly * happen a lot later... */ - bp = (unsigned char*)thdr + thdr->tp_mac; + bp = (unsigned char*)h.raw + tp_mac; run_bpf = (!handle->md.use_bpf) || ((handle->md.use_bpf>1) && handle->md.use_bpf--); if (run_bpf && handle->fcode.bf_insns && (bpf_filter(handle->fcode.bf_insns, bp, - thdr->tp_len, thdr->tp_snaplen) == 0)) + tp_len, tp_snaplen) == 0)) goto skip; - /* check direction and interface index */ - sll = (void*)thdr + TPACKET_ALIGN(sizeof(*thdr)); - if ((sll->sll_ifindex == handle->md.lo_ifindex) && - (sll->sll_pkttype == PACKET_OUTGOING)) - goto skip; + /* + * Do checks based on packet direction. + */ + sll = (void *)h.raw + TPACKET_ALIGN(handle->md.tp_hdrlen); + if (sll->sll_pkttype == PACKET_OUTGOING) { + /* + * Outgoing packet. + * If this is from the loopback device, reject it; + * we'll see the packet as an incoming packet as well, + * and we don't want to see it twice. + */ + if (sll->sll_ifindex == handle->md.lo_ifindex) + goto skip; + + /* + * If the user only wants incoming packets, reject it. + */ + if (handle->direction == PCAP_D_IN) + goto skip; + } else { + /* + * Incoming packet. + * If the user only wants outgoing packets, reject it. + */ + if (handle->direction == PCAP_D_OUT) + goto skip; + } /* get required packet info from ring header */ - pcaphdr.ts.tv_sec = thdr->tp_sec; - pcaphdr.ts.tv_usec = thdr->tp_usec; - pcaphdr.caplen = thdr->tp_snaplen; - pcaphdr.len = thdr->tp_len; + pcaphdr.ts.tv_sec = tp_sec; + pcaphdr.ts.tv_usec = tp_usec; + pcaphdr.caplen = tp_snaplen; + pcaphdr.len = tp_len; /* if required build in place the sll header*/ if (handle->md.cooked) { @@ -2061,7 +2977,9 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, * don't step on the header when we construct * the sll header. */ - if (bp < (u_char *)thdr + TPACKET_HDRLEN) { + if (bp < (u_char *)h.raw + + TPACKET_ALIGN(handle->md.tp_hdrlen) + + sizeof(struct sockaddr_ll)) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "cooked-mode frame doesn't have room for sll header"); return -1; @@ -2083,6 +3001,35 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, pcaphdr.len += SLL_HDR_LEN; } +#ifdef HAVE_TPACKET2 + if (handle->md.tp_version == TPACKET_V2 && h.h2->tp_vlan_tci && + tp_snaplen >= 2 * ETH_ALEN) { + struct vlan_tag *tag; + + bp -= VLAN_TAG_LEN; + memmove(bp, bp + VLAN_TAG_LEN, 2 * ETH_ALEN); + + tag = (struct vlan_tag *)(bp + 2 * ETH_ALEN); + tag->vlan_tpid = htons(ETH_P_8021Q); + tag->vlan_tci = htons(h.h2->tp_vlan_tci); + + pcaphdr.caplen += VLAN_TAG_LEN; + pcaphdr.len += VLAN_TAG_LEN; + } +#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); @@ -2090,7 +3037,16 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, skip: /* next packet */ - thdr->tp_status = TP_STATUS_KERNEL; + 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; @@ -2107,7 +3063,15 @@ 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; @@ -2124,7 +3088,7 @@ pcap_setfilter_linux_mmap(pcap_t *handle, struct bpf_program *filter) for (n=0; n < handle->cc; ++n) { if (--handle->offset < 0) handle->offset = handle->cc - 1; - if (RING_GET_FRAME(handle)->tp_status != TP_STATUS_KERNEL) + if (!pcap_get_ring_frame(handle, TP_STATUS_KERNEL)) break; } @@ -2163,6 +3127,8 @@ iface_get_id(int fd, const char *device, char *ebuf) /* * Bind the socket associated with FD to the given device. + * Return 1 on success, 0 if we should try a SOCK_PACKET socket, + * or a PCAP_ERROR_ value on a hard error. */ static int iface_bind(int fd, int ifindex, char *ebuf) @@ -2177,9 +3143,20 @@ iface_bind(int fd, int ifindex, char *ebuf) sll.sll_protocol = htons(ETH_P_ALL); if (bind(fd, (struct sockaddr *) &sll, sizeof(sll)) == -1) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, - "bind: %s", pcap_strerror(errno)); - return -1; + if (errno == ENETDOWN) { + /* + * Return a "network down" indication, so that + * the application can report that rather than + * saying we had a mysterious failure and + * suggest that they report a problem to the + * libpcap developers. + */ + return PCAP_ERROR_IFACE_NOT_UP; + } else { + snprintf(ebuf, PCAP_ERRBUF_SIZE, + "bind: %s", pcap_strerror(errno)); + return PCAP_ERROR; + } } /* Any pending errors, e.g., network is down? */ @@ -2187,27 +3164,36 @@ iface_bind(int fd, int ifindex, char *ebuf) if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &errlen) == -1) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "getsockopt: %s", pcap_strerror(errno)); - return -2; + return 0; } - if (err > 0) { + if (err == ENETDOWN) { + /* + * Return a "network down" indication, so that + * the application can report that rather than + * saying we had a mysterious failure and + * suggest that they report a problem to the + * libpcap developers. + */ + return PCAP_ERROR_IFACE_NOT_UP; + } else if (err > 0) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "bind: %s", pcap_strerror(err)); - return -2; + return 0; } - return 0; + return 1; } +#ifdef IW_MODE_MONITOR /* * Check whether the device supports the Wireless Extensions. * Returns 1 if it does, 0 if it doesn't, PCAP_ERROR_NO_SUCH_DEVICE * if the device doesn't even exist. */ static int -has_wext(int sock_fd, const char *device) +has_wext(int sock_fd, const char *device, char *ebuf) { -#ifdef IW_MODE_MONITOR struct iwreq ireq; strncpy(ireq.ifr_ifrn.ifrn_name, device, @@ -2215,9 +3201,10 @@ has_wext(int sock_fd, const char *device) ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; if (ioctl(sock_fd, SIOCGIWNAME, &ireq) >= 0) return 1; /* yes */ + snprintf(ebuf, PCAP_ERRBUF_SIZE, + "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno)); if (errno == ENODEV) return PCAP_ERROR_NO_SUCH_DEVICE; -#endif return 0; } @@ -2226,6 +3213,9 @@ has_wext(int sock_fd, const char *device) * Per me si va ne l'etterno dolore, * ... * Lasciate ogne speranza, voi ch'intrate. + * + * XXX - airmon-ng does special stuff with the Orinoco driver and the + * wlan-ng driver. */ typedef enum { MONITOR_WEXT, @@ -2250,21 +3240,63 @@ typedef enum { static int enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) { -#ifdef IW_MODE_MONITOR /* * XXX - at least some adapters require non-Wireless Extensions * mechanisms to turn monitor mode on. * * Atheros cards might require that a separate "monitor virtual access * point" be created, with later versions of the madwifi driver. + * airmon-ng does "wlanconfig ath create wlandev {if} wlanmode + * monitor -bssid", which apparently spits out a line "athN" + * where "athN" is the monitor mode device. To leave monitor + * mode, it destroys the monitor mode device. * * Some Intel Centrino adapters might require private ioctls to get * radio headers; the ipw2200 and ipw3945 drivers allow you to * configure a separate "rtapN" interface to capture in monitor * mode without preventing the adapter from operating normally. + * (airmon-ng doesn't appear to use that, though.) * * It would be Truly Wonderful if mac80211 and nl80211 cleaned this * up, and if all drivers were converted to mac80211 drivers. + * + * 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. */ int err; struct iwreq ireq; @@ -2278,7 +3310,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) /* * Does this device *support* the Wireless Extensions? */ - err = has_wext(sock_fd, device); + err = has_wext(sock_fd, device, handle->errbuf); if (err <= 0) return err; /* either it doesn't or the device doesn't even exist */ /* @@ -2295,7 +3327,7 @@ 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) { @@ -2319,16 +3351,17 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno)); return PCAP_ERROR; } - priv = malloc(ireq.u.data.length); + priv = malloc(ireq.u.data.length * sizeof (struct iw_priv_args)); if (priv == NULL) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "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)); + free(priv); return PCAP_ERROR; } @@ -2344,8 +3377,10 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) * Hostap driver, use this one. * Set monitor mode first. * You can set it to 0 to get DLT_IEEE80211, - * 1 to get DLT_PRISM, or 2 to get - * DLT_IEEE80211_RADIO_AVS. + * 1 to get DLT_PRISM, 2 to get + * DLT_IEEE80211_RADIO_AVS, and, with more + * recent versions of the driver, 3 to get + * DLT_IEEE80211_RADIO. */ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) break; @@ -2481,6 +3516,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) } } } + free(priv); /* * XXX - ipw3945? islism? @@ -2558,7 +3594,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) * Note that we have to put the old mode back * when we close the device. */ - handle->md.must_clear |= MUST_CLEAR_RFMON; + handle->md.must_do_on_close |= MUST_CLEAR_RFMON; /* * Add this to the list of pcaps to close @@ -2588,6 +3624,12 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) return PCAP_ERROR_RFMON_NOTSUP; } + /* + * XXX - airmon-ng does "iwconfig {if} key off" after setting + * monitor mode and setting the channel, and then does + * "iwconfig up". + */ + /* * Now select the appropriate radio header. */ @@ -2601,8 +3643,19 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) case MONITOR_HOSTAP: /* - * Select the AVS header if we can, otherwise - * select the Prism header. + * Try to select the radiotap header. + */ + memset(&ireq, 0, sizeof ireq); + 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; + args[0] = 3; /* request radiotap header */ + memcpy(ireq.u.name, args, sizeof (int)); + if (ioctl(sock_fd, cmd, &ireq) != -1) + break; /* success */ + + /* + * That failed. Try to select the AVS header. */ memset(&ireq, 0, sizeof ireq); strncpy(ireq.ifr_ifrn.ifrn_name, device, @@ -2610,18 +3663,19 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; args[0] = 2; /* request AVS header */ memcpy(ireq.u.name, args, sizeof (int)); - if (ioctl(sock_fd, cmd, &ireq) == -1) { - /* - * Failure - try the Prism header. - */ - memset(&ireq, 0, sizeof ireq); - 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; - args[0] = 1; /* request Prism header */ - memcpy(ireq.u.name, args, sizeof (int)); - ioctl(sock_fd, cmd, &ireq); - } + if (ioctl(sock_fd, cmd, &ireq) != -1) + break; /* success */ + + /* + * That failed. Try to select the Prism header. + */ + memset(&ireq, 0, sizeof ireq); + 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; + args[0] = 1; /* request Prism header */ + memcpy(ireq.u.name, args, sizeof (int)); + ioctl(sock_fd, cmd, &ireq); break; case MONITOR_PRISM: @@ -2732,7 +3786,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) * Note that we have to put the old mode back when we * close the device. */ - handle->md.must_clear |= MUST_CLEAR_RFMON; + handle->md.must_do_on_close |= MUST_CLEAR_RFMON; /* * Add this to the list of pcaps to close when we exit. @@ -2740,13 +3794,41 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) pcap_add_to_pcaps_to_close(handle); return 1; -#else +} +#endif /* IW_MODE_MONITOR */ + +/* + * Try various mechanisms to enter monitor mode. + */ +static int +enter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device) +{ +#if defined(HAVE_LIBNL) || defined(IW_MODE_MONITOR) + int ret; +#endif + +#ifdef HAVE_LIBNL + ret = enter_rfmon_mode_mac80211(handle, sock_fd, device); + if (ret < 0) + return ret; /* error attempting to do so */ + if (ret == 1) + return 1; /* success */ +#endif /* HAVE_LIBNL */ + +#ifdef IW_MODE_MONITOR + ret = enter_rfmon_mode_wext(handle, sock_fd, device); + if (ret < 0) + return ret; /* error attempting to do so */ + if (ret == 1) + return 1; /* success */ +#endif /* IW_MODE_MONITOR */ + /* - * We don't have the Wireless Extensions available, so we can't - * do monitor mode. + * Either none of the mechanisms we know about work or none + * of those mechanisms are available, so we can't do monitor + * mode. */ return 0; -#endif } #endif /* HAVE_PF_PACKET_SOCKETS */ @@ -2772,7 +3854,7 @@ activate_old(pcap_t *handle) if (handle->fd == -1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "socket: %s", pcap_strerror(errno)); - return PCAP_ERROR; + return PCAP_ERROR_PERM_DENIED; } /* It worked - we are using the old interface */ @@ -2783,7 +3865,7 @@ activate_old(pcap_t *handle) /* Bind to the given device */ - if (!device) { + if (strcmp(device, "any") == 0) { strncpy(handle->errbuf, "pcap_activate: The \"any\" device isn't supported on 2.0[.x]-kernel systems", PCAP_ERRBUF_SIZE); return PCAP_ERROR; @@ -2848,7 +3930,7 @@ activate_old(pcap_t *handle) pcap_strerror(errno)); return PCAP_ERROR; } - handle->md.must_clear |= MUST_CLEAR_PROMISC; + handle->md.must_do_on_close |= MUST_CLEAR_PROMISC; /* * Add this to the list of pcaps @@ -3007,14 +4089,14 @@ iface_get_arptype(int fd, const char *device, char *ebuf) strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); if (ioctl(fd, SIOCGIFHWADDR, &ifr) == -1) { + snprintf(ebuf, PCAP_ERRBUF_SIZE, + "SIOCGIFHWADDR: %s", pcap_strerror(errno)); if (errno == ENODEV) { /* * No such device. */ return PCAP_ERROR_NO_SUCH_DEVICE; } - snprintf(ebuf, PCAP_ERRBUF_SIZE, - "SIOCGIFHWADDR: %s", pcap_strerror(errno)); return PCAP_ERROR; } @@ -3023,7 +4105,7 @@ 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; @@ -3056,26 +4138,33 @@ 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;