]> The Tcpdump Group git mirrors - libpcap/blobdiff - pcap-linux.c
Travis: Add .travis.yml (same as in version 1.4)
[libpcap] / pcap-linux.c
index 16861acc88a18a606ab5d22855df5b15bb241885..e5c3afa7d86da2cc7a427444bb64cfd591299d90 100644 (file)
@@ -127,11 +127,13 @@ static const char rcsid[] _U_ =
 #include <fcntl.h>
 #include <string.h>
 #include <limits.h>
+#include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 #include <sys/utsname.h>
 #include <sys/mman.h>
 #include <linux/if.h>
+#include <linux/if_packet.h>
 #include <netinet/in.h>
 #include <linux/if_ether.h>
 #include <net/if_arp.h>
@@ -166,9 +168,12 @@ static const char rcsid[] _U_ =
 #include "pcap-can-linux.h"
 #endif
 
+#if PCAP_SUPPORT_CANUSB
+#include "pcap-canusb-linux.h"
+#endif
+
 #ifdef PCAP_SUPPORT_NETFILTER
-int netfilter_platform_finddevs(pcap_if_t **alldevsp, char *err_str);
-pcap_t *nflog_create(const char *device, char *ebuf);
+#include "pcap-netfilter-linux.h"
 #endif
 
 /*
@@ -313,7 +318,7 @@ typedef int         socklen_t;
 /*
  * Prototypes for internal functions and methods.
  */
-static void map_arphrd_to_dlt(pcap_t *, int, int);
+static void map_arphrd_to_dlt(pcap_t *, int, int, const char *, int);
 #ifdef HAVE_PF_PACKET_SOCKETS
 static short int map_packet_type_to_sll_type(short int);
 #endif
@@ -419,8 +424,15 @@ pcap_create(const char *device, char *ebuf)
        }
 #endif
 
+#if PCAP_SUPPORT_CANUSB
+  if (strstr(device, "canusb")) {
+    return canusb_create(device, ebuf);
+  }
+#endif
+
 #ifdef PCAP_SUPPORT_CAN
-       if (strstr(device, "can") || strstr(device, "vcan")) {
+       if ((strncmp(device, "can", 3) == 0 && isdigit(device[3])) ||
+           (strncmp(device, "vcan", 4) == 0 && isdigit(device[4]))) {
                return can_create(device, ebuf);
        }
 #endif
@@ -862,6 +874,18 @@ added:
        nanosleep(&delay, NULL);
 #endif
 
+       /*
+        * If we haven't already done so, arrange to have
+        * "pcap_close_all()" called when we exit.
+        */
+       if (!pcap_do_addexit(handle)) {
+               /*
+                * "atexit()" failed; don't put the interface
+                * in rfmon mode, just give up.
+                */
+               return PCAP_ERROR_RFMON_NOTSUP;
+       }
+
        /*
         * Now configure the monitor interface up.
         */
@@ -1596,32 +1620,40 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
        }
 
 #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;
+       if (handle->md.vlan_offset != -1) {
+               for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+                       struct tpacket_auxdata *aux;
+                       unsigned int len;
+                       struct vlan_tag *tag;
 
-               aux = (struct tpacket_auxdata *)CMSG_DATA(cmsg);
-               if (aux->tp_vlan_tci == 0)
-                       continue;
+                       if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct tpacket_auxdata)) ||
+                           cmsg->cmsg_level != SOL_PACKET ||
+                           cmsg->cmsg_type != PACKET_AUXDATA)
+                               continue;
 
-               len = packet_len > iov.iov_len ? iov.iov_len : packet_len;
-               if (len < 2 * ETH_ALEN)
-                       break;
+                       aux = (struct tpacket_auxdata *)CMSG_DATA(cmsg);
+#if defined(TP_STATUS_VLAN_VALID)
+                       if ((aux->tp_vlan_tci == 0) && !(aux->tp_status & TP_STATUS_VLAN_VALID))
+#else
+                       if (aux->tp_vlan_tci == 0) /* this is ambigious but without the
+                                               TP_STATUS_VLAN_VALID flag, there is
+                                               nothing that we can do */
+#endif
+                               continue;
 
-               bp -= VLAN_TAG_LEN;
-               memmove(bp, bp + VLAN_TAG_LEN, 2 * ETH_ALEN);
+                       len = packet_len > iov.iov_len ? iov.iov_len : packet_len;
+                       if (len < (unsigned int) handle->md.vlan_offset)
+                               break;
 
-               tag = (struct vlan_tag *)(bp + 2 * ETH_ALEN);
-               tag->vlan_tpid = htons(ETH_P_8021Q);
-               tag->vlan_tci = htons(aux->tp_vlan_tci);
+                       bp -= VLAN_TAG_LEN;
+                       memmove(bp, bp + VLAN_TAG_LEN, handle->md.vlan_offset);
 
-               packet_len += VLAN_TAG_LEN;
+                       tag = (struct vlan_tag *)(bp + handle->md.vlan_offset);
+                       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 */
@@ -1929,6 +1961,8 @@ scan_sys_class_net(pcap_if_t **devlistp, char *errbuf)
        DIR *sys_class_net_d;
        int fd;
        struct dirent *ent;
+       char subsystem_path[PATH_MAX+1];
+       struct stat statb;
        char *p;
        char name[512]; /* XXX - pick a size */
        char *q, *saveq;
@@ -1973,11 +2007,42 @@ scan_sys_class_net(pcap_if_t **devlistp, char *errbuf)
                }
 
                /*
-                * Ignore directories (".", "..", and any subdirectories).
+                * Ignore "." and "..".
                 */
-               if (ent->d_type == DT_DIR)
+               if (strcmp(ent->d_name, ".") == 0 ||
+                   strcmp(ent->d_name, "..") == 0)
                        continue;
 
+               /*
+                * Ignore plain files; they do not have subdirectories
+                * and thus have no attributes.
+                */
+               if (ent->d_type == DT_REG)
+                       continue;
+
+               /*
+                * Is there an "ifindex" file under that name?
+                * (We don't care whether it's a directory or
+                * a symlink; older kernels have directories
+                * for devices, newer kernels have symlinks to
+                * directories.)
+                */
+               snprintf(subsystem_path, sizeof subsystem_path,
+                   "/sys/class/net/%s/ifindex", ent->d_name);
+               if (lstat(subsystem_path, &statb) != 0) {
+                       /*
+                        * Stat failed.  Either there was an error
+                        * other than ENOENT, and we don't know if
+                        * this is an interface, or it's ENOENT,
+                        * and either some part of "/sys/class/net/{if}"
+                        * disappeared, in which case it probably means
+                        * the interface disappeared, or there's no
+                        * "ifindex" file, which means it's not a
+                        * network interface.
+                        */
+                       continue;
+               }
+
                /*
                 * Get the interface name.
                 */
@@ -2288,6 +2353,11 @@ pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
                return (-1);
 #endif
 
+#if PCAP_SUPPORT_CANUSB
+  if (canusb_platform_finddevs(alldevsp, errbuf) < 0)
+    return (-1);
+#endif
+
        return (0);
 }
 
@@ -2517,6 +2587,51 @@ map_packet_type_to_sll_type(short int sll_pkttype)
 }
 #endif
 
+static int
+is_wifi(int sock_fd
+#ifndef IW_MODE_MONITOR
+_U_
+#endif
+, const char *device)
+{
+       char *pathstr;
+       struct stat statb;
+#ifdef IW_MODE_MONITOR
+       char errbuf[PCAP_ERRBUF_SIZE];
+#endif
+
+       /*
+        * See if there's a sysfs wireless directory for it.
+        * If so, it's a wireless interface.
+        */
+       if (asprintf(&pathstr, "/sys/class/net/%s/wireless", device) == -1) {
+               /*
+                * Just give up here.
+                */
+               return 0;
+       }
+       if (stat(pathstr, &statb) == 0) {
+               free(pathstr);
+               return 1;
+       }
+       free(pathstr);
+
+#ifdef IW_MODE_MONITOR
+       /*
+        * OK, maybe it's not wireless, or maybe this kernel doesn't
+        * support sysfs.  Try the wireless extensions.
+        */
+       if (has_wext(sock_fd, device, errbuf) == 1) {
+               /*
+                * It supports the wireless extensions, so it's a Wi-Fi
+                * device.
+                */
+               return 1;
+       }
+#endif
+       return 0;
+}
+
 /*
  *  Linux uses the ARP hardware type to identify the type of an
  *  interface. pcap uses the DLT_xxx constants for this. This
@@ -2535,13 +2650,33 @@ map_packet_type_to_sll_type(short int sll_pkttype)
  *
  *  Sets the link type to -1 if unable to map the type.
  */
-static void map_arphrd_to_dlt(pcap_t *handle, int arptype, int cooked_ok)
+static void map_arphrd_to_dlt(pcap_t *handle, int sock_fd, int arptype,
+                             const char *device, int cooked_ok)
 {
+       static const char cdma_rmnet[] = "cdma_rmnet";
+
        switch (arptype) {
 
        case ARPHRD_ETHER:
                /*
-                * This is (presumably) a real Ethernet capture; give it a
+                * For various annoying reasons having to do with DHCP
+                * software, some versions of Android give the mobile-
+                * phone-network interface an ARPHRD_ value of
+                * ARPHRD_ETHER, even though the packets supplied by
+                * that interface have no link-layer header, and begin
+                * with an IP header, so that the ARPHRD_ value should
+                * be ARPHRD_NONE.
+                *
+                * Detect those devices by checking the device name, and
+                * use DLT_RAW for them.
+                */
+               if (strncmp(device, cdma_rmnet, sizeof cdma_rmnet - 1) == 0) {
+                       handle->linktype = DLT_RAW;
+                       return;
+               }
+       
+               /*
+                * Is this a real Ethernet device?  If so, give it a
                 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
                 * that an application can let you choose it, in case you're
                 * capturing DOCSIS traffic that a Cisco Cable Modem
@@ -2550,21 +2685,27 @@ static void map_arphrd_to_dlt(pcap_t *handle, int arptype, int cooked_ok)
                 * DOCSIS frames out on the wire inside the low-level
                 * Ethernet framing).
                 *
-                * XXX - are there any sorts of "fake Ethernet" that have
-                * ARPHRD_ETHER but that *shouldn't offer DLT_DOCSIS as
+                * XXX - are there any other sorts of "fake Ethernet" that
+                * have ARPHRD_ETHER but that shouldn't offer DLT_DOCSIS as
                 * a Cisco CMTS won't put traffic onto it or get traffic
                 * bridged onto it?  ISDN is handled in "activate_new()",
-                * as we fall back on cooked mode there; are there any
+                * as we fall back on cooked mode there, and we use
+                * is_wifi() to check for 802.11 devices; are there any
                 * others?
                 */
-               handle->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
-               /*
-                * If that fails, just leave the list empty.
-                */
-               if (handle->dlt_list != NULL) {
-                       handle->dlt_list[0] = DLT_EN10MB;
-                       handle->dlt_list[1] = DLT_DOCSIS;
-                       handle->dlt_count = 2;
+               if (!is_wifi(sock_fd, device)) {
+                       /*
+                        * It's not a Wi-Fi device; offer DOCSIS.
+                        */
+                       handle->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
+                       /*
+                        * If that fails, just leave the list empty.
+                        */
+                       if (handle->dlt_list != NULL) {
+                               handle->dlt_list[0] = DLT_EN10MB;
+                               handle->dlt_list[1] = DLT_DOCSIS;
+                               handle->dlt_count = 2;
+                       }
                }
                /* FALLTHROUGH */
 
@@ -2965,7 +3106,7 @@ activate_new(pcap_t *handle)
                        close(sock_fd);
                        return arptype;
                }
-               map_arphrd_to_dlt(handle, arptype, 1);
+               map_arphrd_to_dlt(handle, sock_fd, arptype, device, 1);
                if (handle->linktype == -1 ||
                    handle->linktype == DLT_LINUX_SLL ||
                    handle->linktype == DLT_LINUX_IRDA ||
@@ -3154,6 +3295,24 @@ activate_new(pcap_t *handle)
        }
        handle->bufsize = handle->snapshot;
 
+       /*
+        * Set the offset at which to insert VLAN tags.
+        */
+       switch (handle->linktype) {
+
+       case DLT_EN10MB:
+               handle->md.vlan_offset = 2 * ETH_ALEN;
+               break;
+
+       case DLT_LINUX_SLL:
+               handle->md.vlan_offset = 14;
+               break;
+
+       default:
+               handle->md.vlan_offset = -1; /* unknown */
+               break;
+       }
+
        /* Save the socket FD in the pcap structure */
        handle->fd = sock_fd;
 
@@ -3892,7 +4051,7 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback,
                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", 
+                               "offset %u + caplen %u > frame len %d", 
                                tp_mac, tp_snaplen, handle->bufsize);
                        return -1;
                }
@@ -3993,14 +4152,20 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback,
                }
 
 #ifdef HAVE_TPACKET2
-               if (handle->md.tp_version == TPACKET_V2 && h.h2->tp_vlan_tci &&
-                   tp_snaplen >= 2 * ETH_ALEN) {
+               if ((handle->md.tp_version == TPACKET_V2) &&
+#if defined(TP_STATUS_VLAN_VALID)
+               (h.h2->tp_vlan_tci || (h.h2->tp_status & TP_STATUS_VLAN_VALID)) &&
+#else
+               h.h2->tp_vlan_tci &&
+#endif
+                   handle->md.vlan_offset != -1 &&
+                   tp_snaplen >= (unsigned int) handle->md.vlan_offset) {
                        struct vlan_tag *tag;
 
                        bp -= VLAN_TAG_LEN;
-                       memmove(bp, bp + VLAN_TAG_LEN, 2 * ETH_ALEN);
+                       memmove(bp, bp + VLAN_TAG_LEN, handle->md.vlan_offset);
 
-                       tag = (struct vlan_tag *)(bp + 2 * ETH_ALEN);
+                       tag = (struct vlan_tag *)(bp + handle->md.vlan_offset);
                        tag->vlan_tpid = htons(ETH_P_8021Q);
                        tag->vlan_tci = htons(h.h2->tp_vlan_tci);
 
@@ -4311,6 +4476,7 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device)
         * radio metadata.
         */
        montype = MONITOR_WEXT;
+       cmd = 0;
 
        /*
         * Try to get all the Wireless Extensions private ioctls
@@ -4371,7 +4537,6 @@ enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device)
                 * Look for private ioctls to turn monitor mode on or, if
                 * monitor mode is on, to set the header type.
                 */
-               cmd = 0;
                for (i = 0; i < ireq.u.data.length; i++) {
                        if (strcmp(priv[i].name, "monitor_type") == 0) {
                                /*
@@ -4908,7 +5073,7 @@ iface_ethtool_ioctl(pcap_t *handle, int cmd, const char *cmdname)
        eval.cmd = cmd;
        ifr.ifr_data = (caddr_t)&eval;
        if (ioctl(handle->fd, SIOCETHTOOL, &ifr) == -1) {
-               if (errno == EOPNOTSUPP) {
+               if (errno == EOPNOTSUPP || errno == EINVAL) {
                        /*
                         * OK, let's just return 0, which, in our
                         * case, either means "no, what we're asking
@@ -5058,7 +5223,7 @@ activate_old(pcap_t *handle)
         * Try to find the DLT_ type corresponding to that
         * link-layer type.
         */
-       map_arphrd_to_dlt(handle, arptype, 0);
+       map_arphrd_to_dlt(handle, handle->fd, arptype, device, 0);
        if (handle->linktype == -1) {
                snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
                         "unknown arptype %d", arptype);
@@ -5186,6 +5351,12 @@ activate_old(pcap_t *handle)
         */
        handle->offset   = 0;
 
+       /*
+        * SOCK_PACKET sockets don't supply information from
+        * stripped VLAN tags.
+        */
+       handle->md.vlan_offset = -1; /* unknown */
+
        return 1;
 }
 
@@ -5392,13 +5563,19 @@ fix_offset(struct bpf_insn *p)
                 * header.
                 */
                p->k -= SLL_HDR_LEN;
+       } else if (p->k == 0) {
+               /*
+                * It's the packet type field; map it to the special magic
+                * kernel offset for that field.
+                */
+               p->k = SKF_AD_OFF + SKF_AD_PKTTYPE;
        } else if (p->k == 14) {
                /*
                 * It's the protocol field; map it to the special magic
                 * kernel offset for that field.
                 */
                p->k = SKF_AD_OFF + SKF_AD_PROTOCOL;
-       } else {
+       } else if ((bpf_int32)(p->k) > 0) {
                /*
                 * It's within the header, but it's not one of those
                 * fields; we can't do that in the kernel, so punt