diff options
author | rpaulo <rpaulo@FreeBSD.org> | 2010-10-29 18:43:23 +0000 |
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committer | rpaulo <rpaulo@FreeBSD.org> | 2010-10-29 18:43:23 +0000 |
commit | 22f795f2fd7f982a2847bc9fc73e297abc7e2fbf (patch) | |
tree | 99c17a1bdbff3dabc0f310509b912bf2775d2145 /contrib/libpcap/pcap-linux.c | |
parent | 2631ae0f3d6c77323709cd35d1f7241624662320 (diff) | |
parent | 724e1a015907ca989c4e1cb30c7ee4e88f26fbff (diff) | |
download | FreeBSD-src-22f795f2fd7f982a2847bc9fc73e297abc7e2fbf.zip FreeBSD-src-22f795f2fd7f982a2847bc9fc73e297abc7e2fbf.tar.gz |
Merge libpcap-1.1.1.
Diffstat (limited to 'contrib/libpcap/pcap-linux.c')
-rw-r--r-- | contrib/libpcap/pcap-linux.c | 1645 |
1 files changed, 1454 insertions, 191 deletions
diff --git a/contrib/libpcap/pcap-linux.c b/contrib/libpcap/pcap-linux.c index 8161af0..af12543 100644 --- a/contrib/libpcap/pcap-linux.c +++ b/contrib/libpcap/pcap-linux.c @@ -30,11 +30,44 @@ * based on previous works of: * Simon Patarin <patarin@cs.unibo.it> * Phil Wood <cpw@lanl.gov> + * + * 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 1.129.2.29 2008-10-28 00:50:39 guy Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.164 2008-12-14 22:00:57 guy Exp $ (LBL)"; #endif /* @@ -80,31 +113,50 @@ static const char rcsid[] _U_ = */ +#define _GNU_SOURCE + #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <errno.h> +#include <stdio.h> #include <stdlib.h> +#include <ctype.h> #include <unistd.h> #include <fcntl.h> #include <string.h> +#include <limits.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <sys/utsname.h> #include <sys/mman.h> -#include <net/if.h> +#include <linux/if.h> #include <netinet/in.h> #include <linux/if_ether.h> #include <net/if_arp.h> #include <poll.h> +#include <dirent.h> /* * Got Wireless Extensions? */ #ifdef HAVE_LINUX_WIRELESS_H #include <linux/wireless.h> -#endif +#endif /* HAVE_LINUX_WIRELESS_H */ + +/* + * Got libnl? + */ +#ifdef HAVE_LIBNL +#include <linux/nl80211.h> + +#include <netlink/genl/genl.h> +#include <netlink/genl/family.h> +#include <netlink/genl/ctrl.h> +#include <netlink/msg.h> +#include <netlink/attr.h> +#endif /* HAVE_LIBNL */ #include "pcap-int.h" #include "pcap/sll.h" @@ -118,6 +170,10 @@ 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 @@ -126,6 +182,10 @@ 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. @@ -262,6 +322,8 @@ 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 /* @@ -274,14 +336,17 @@ 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); +#ifdef IW_MODE_MONITOR static int has_wext(int sock_fd, const char *device, char *ebuf); -static int enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, +#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); @@ -297,6 +362,12 @@ 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); @@ -309,14 +380,27 @@ 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, "usb")) { + if (strstr(device, "usbmon")) { return usb_create(device, ebuf); } #endif @@ -330,22 +414,462 @@ 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 -pcap_can_set_rfmon_linux(pcap_t *p) +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 *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 @@ -359,7 +883,7 @@ 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; } @@ -367,7 +891,7 @@ 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) { @@ -379,6 +903,8 @@ pcap_can_set_rfmon_linux(pcap_t *p) } 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; } @@ -388,6 +914,67 @@ pcap_can_set_rfmon_linux(pcap_t *p) } /* + * 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 * be solved without some daemon taking care of managing usage counts. @@ -402,16 +989,20 @@ pcap_can_set_rfmon_linux(pcap_t *p) 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. @@ -449,8 +1040,25 @@ static void pcap_cleanup_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. @@ -474,7 +1082,7 @@ static void pcap_cleanup_linux( pcap_t *handle ) strerror(errno)); } } -#endif +#endif /* IW_MODE_MONITOR */ /* * Take this pcap out of the list of pcaps for which we @@ -483,6 +1091,10 @@ static void pcap_cleanup_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; @@ -503,7 +1115,6 @@ pcap_activate_linux(pcap_t *handle) { const char *device; int status = 0; - int activate_ok = 0; device = handle->opt.source; @@ -518,12 +1129,11 @@ pcap_activate_linux(pcap_t *handle) 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. */ @@ -531,15 +1141,22 @@ pcap_activate_linux(pcap_t *handle) "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) ); 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 @@ -552,27 +1169,57 @@ pcap_activate_linux(pcap_t *handle) */ if ((status = activate_new(handle)) == 1) { - activate_ok = 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 (status == 0) { /* Non-fatal error; try old way */ - if ((status = 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; } + /* + * 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. @@ -708,12 +1355,12 @@ 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) @@ -725,17 +1372,32 @@ 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; } } @@ -893,7 +1555,7 @@ 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; @@ -1008,6 +1670,18 @@ 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. @@ -1028,6 +1702,8 @@ 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. @@ -1091,20 +1767,300 @@ 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) + 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. */ static const char any_descr[] = "Pseudo-device that captures on all interfaces"; @@ -1112,25 +2068,66 @@ 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 @@ -1142,7 +2139,8 @@ 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; @@ -1195,13 +2193,13 @@ 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: @@ -1275,6 +2273,13 @@ 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? @@ -1405,6 +2410,12 @@ 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 */ @@ -1657,19 +2668,24 @@ static int activate_new(pcap_t *handle) { #ifdef HAVE_PF_PACKET_SOCKETS - int sock_fd = -1, arptype, val; + 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", @@ -1704,7 +2720,7 @@ 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; @@ -1715,7 +2731,7 @@ 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); @@ -1729,6 +2745,15 @@ 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) { @@ -1819,15 +2844,23 @@ activate_new(pcap_t *handle) } } 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 @@ -1852,10 +2885,13 @@ 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; @@ -1920,16 +2956,32 @@ 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 == 0) + 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 @@ -1940,6 +2992,7 @@ activate_mmap(pcap_t *handle) 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 */ @@ -1965,11 +3018,13 @@ prepare_tpacket_socket(pcap_t *handle) len = sizeof(val); if (getsockopt(handle->fd, SOL_PACKET, PACKET_HDRLEN, &val, &len) < 0) { if (errno == ENOPROTOOPT) - return 1; + 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 socket %d: %d-%s", - handle->fd, errno, pcap_strerror(errno)); - return 0; + "can't get TPACKET_V2 header len on packet socket: %s", + pcap_strerror(errno)); + return -1; } handle->md.tp_hdrlen = val; @@ -1977,9 +3032,9 @@ prepare_tpacket_socket(pcap_t *handle) if (setsockopt(handle->fd, SOL_PACKET, PACKET_VERSION, &val, sizeof(val)) < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "can't activate TPACKET_V2 on socket %d: %d-%s", - handle->fd, errno, pcap_strerror(errno)); - return 0; + "can't activate TPACKET_V2 on packet socket: %s", + pcap_strerror(errno)); + return -1; } handle->md.tp_version = TPACKET_V2; @@ -1988,33 +3043,19 @@ prepare_tpacket_socket(pcap_t *handle) if (setsockopt(handle->fd, SOL_PACKET, PACKET_RESERVE, &val, sizeof(val)) < 0) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, - "can't set up reserve on socket %d: %d-%s", - handle->fd, errno, pcap_strerror(errno)); - return 0; + "can't set up reserve on packet socket: %s", + pcap_strerror(errno)); + return -1; } #endif /* HAVE_TPACKET2 */ return 1; } -static void -compute_ring_block(int frame_size, unsigned *block_size, unsigned *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. */ - *block_size = getpagesize(); - while (*block_size < frame_size) - *block_size <<= 1; - - *frames_per_block = *block_size/frame_size; -} - 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 @@ -2026,53 +3067,83 @@ create_ring(pcap_t *handle) 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(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; i<req.tp_block_nr; ++i) { - void *base = &handle->bp[i*req.tp_block_size]; + void *base = &handle->md.mmapbuf[i*req.tp_block_size]; for (j=0; j<frames_per_block; ++j, ++handle->offset) { RING_GET_FRAME(handle) = base; base += req.tp_frame_size; @@ -2095,21 +3166,49 @@ destroy_ring(pcap_t *handle) (void *) &req, sizeof(req)); /* if ring is mapped, unmap it*/ - if (handle->bp) { - /* need to re-compute the ring size */ - unsigned frames_per_block, block_size; - compute_ring_block(handle->bufsize, &block_size, &frames_per_block); - - /* do not perform sanity check here: we can't recover any error */ - munmap(handle->bp, block_size * handle->cc / frames_per_block); - handle->bp = 0; + if (handle->md.mmapbuf) { + /* do not test for mmap failure, as we can't recover from any error */ + munmap(handle->md.mmapbuf, handle->md.mmapbuflen); + handle->md.mmapbuf = NULL; } } +/* + * Special one-shot callback, used for pcap_next() and pcap_next_ex(), + * for Linux mmapped capture. + * + * The problem is that pcap_next() and pcap_next_ex() expect the packet + * data handed to the callback to be valid after the callback returns, + * but pcap_read_linux_mmap() has to release that packet as soon as + * the callback returns (otherwise, the kernel thinks there's still + * at least one unprocessed packet available in the ring, so a select() + * will immediately return indicating that there's data to process), so, + * in the callback, we have to make a copy of the packet. + * + * Yes, this means that, if the capture is using the ring buffer, using + * pcap_next() or pcap_next_ex() requires more copies than using + * pcap_loop() or pcap_dispatch(). If that bothers you, don't use + * pcap_next() or pcap_next_ex(). + */ +static void +pcap_oneshot_mmap(u_char *user, const struct pcap_pkthdr *h, + const u_char *bytes) +{ + struct oneshot_userdata *sp = (struct oneshot_userdata *)user; + + *sp->hdr = *h; + memcpy(sp->pd->md.oneshot_buffer, bytes, h->caplen); + *sp->pkt = sp->pd->md.oneshot_buffer; +} + static void pcap_cleanup_linux_mmap( pcap_t *handle ) { destroy_ring(handle); + if (handle->md.oneshot_buffer != NULL) { + free(handle->md.oneshot_buffer); + handle->md.oneshot_buffer = NULL; + } pcap_cleanup_linux(handle); } @@ -2127,11 +3226,26 @@ pcap_setnonblock_mmap(pcap_t *p, int nonblock, char *errbuf) /* map each value to the corresponding 2's complement, to * preserve the timeout value provided with pcap_set_timeout */ if (nonblock) { - if (p->md.timeout > 0) + if (p->md.timeout >= 0) { + /* + * Timeout is non-negative, so we're not already + * in non-blocking mode; set it to the 2's + * complement, to make it negative, as an + * indication that we're in non-blocking mode. + */ p->md.timeout = p->md.timeout*-1 - 1; - } else - if (p->md.timeout < 0) + } + } else { + if (p->md.timeout < 0) { + /* + * Timeout is negative, so we're not already + * in blocking mode; reverse the previous + * operation, to make the timeout non-negative + * again. + */ p->md.timeout = (p->md.timeout+1)*-1; + } + } return 0; } @@ -2158,35 +3272,95 @@ 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); } @@ -2258,11 +3432,33 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, tp_len, tp_snaplen) == 0)) goto skip; - /* check direction and interface index */ + /* + * Do checks based on packet direction. + */ sll = (void *)h.raw + TPACKET_ALIGN(handle->md.tp_hdrlen); - if ((sll->sll_ifindex == handle->md.lo_ifindex) && - (sll->sll_pkttype == PACKET_OUTGOING)) - goto skip; + 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 = tp_sec; @@ -2331,6 +3527,18 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, } #endif + /* + * The only way to tell the kernel to cut off the + * packet at a snapshot length is with a filter program; + * if there's no filter program, the kernel won't cut + * the packet off. + * + * Trim the snapshot length to be no longer than the + * specified snapshot length. + */ + if (pcaphdr.caplen > handle->snapshot) + pcaphdr.caplen = handle->snapshot; + /* pass the packet to the user */ pkts++; callback(user, &pcaphdr, bp); @@ -2354,7 +3562,7 @@ skip: /* check for break loop condition*/ if (handle->break_loop) { handle->break_loop = 0; - return -2; + return PCAP_ERROR_BREAK; } } return pkts; @@ -2364,7 +3572,15 @@ 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; @@ -2478,6 +3694,7 @@ iface_bind(int fd, int ifindex, char *ebuf) 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 @@ -2486,7 +3703,6 @@ iface_bind(int fd, int ifindex, char *ebuf) static int has_wext(int sock_fd, const char *device, char *ebuf) { -#ifdef IW_MODE_MONITOR struct iwreq ireq; strncpy(ireq.ifr_ifrn.ifrn_name, device, @@ -2498,7 +3714,6 @@ has_wext(int sock_fd, const char *device, char *ebuf) "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno)); if (errno == ENODEV) return PCAP_ERROR_NO_SUCH_DEVICE; -#endif return 0; } @@ -2534,7 +3749,6 @@ 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. @@ -2622,7 +3836,7 @@ 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) { @@ -2652,7 +3866,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) "malloc: %s", pcap_strerror(errno)); return PCAP_ERROR; } - ireq.u.data.pointer = priv; + ireq.u.data.pointer = (void *)priv; if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) == -1) { snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno)); @@ -2672,8 +3886,10 @@ 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; @@ -2887,7 +4103,7 @@ 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 @@ -2936,8 +4152,19 @@ 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, @@ -2945,18 +4172,19 @@ 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: @@ -3067,7 +4295,7 @@ 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. @@ -3075,13 +4303,41 @@ 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 */ @@ -3118,7 +4374,7 @@ 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; @@ -3183,7 +4439,7 @@ 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 @@ -3358,7 +4614,7 @@ 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; @@ -3391,26 +4647,33 @@ 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; |