Handle VLAN tags in cooked mode.

Use Jakub Zawadzki's changes for that, but put the VLAN tag offset into
the pcap structure and calculate it at activation time.

diff --git a/pcap-int.h b/pcap-int.h
index a34ee8e7d9b4ea2c103e9f263785dee97b939522..6616f176c059ac38891d9b1b2cfe56ae0dcc29cb 100644 (file)
--- a/pcap-int.h
+++ b/pcap-int.h
@@ -144,7 +144,7 @@ struct pcap_md {
        char    *mondevice;     /* mac80211 monitor device we created */
        u_char  *mmapbuf;       /* memory-mapped region pointer */
        size_t  mmapbuflen;     /* size of region */
-       int     add_vlan_tags;  /* 1 if we should insert VLAN tags */
+       int     vlan_offset;    /* offset at which to insert vlan tags; if -1, don't insert */
        u_int   tp_version;     /* version of tpacket_hdr for mmaped ring */
        u_int   tp_hdrlen;      /* hdrlen of tpacket_hdr for mmaped ring */
        u_char  *oneshot_buffer; /* buffer for copy of packet */

diff --git a/pcap-linux.c b/pcap-linux.c
index caf1a256342242e79380692a3d027a479044596f..70ad282d4571b3fdfdc5f25b8d68c1f179851cfb 100644 (file)
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -1618,7 +1618,7 @@ 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)
-       if (handle->md.add_vlan_tags) {
+       if (handle->md.vlan_offset != -1) {
                for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
                        struct tpacket_auxdata *aux;
                        unsigned int len;
@@ -1634,13 +1634,13 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
                                continue;
 
                        len = packet_len > iov.iov_len ? iov.iov_len : packet_len;
-                       if (len < 2 * ETH_ALEN)
+                       if (len < (unsigned int) handle->md.vlan_offset)
                                break;
 
                        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(aux->tp_vlan_tci);
 
@@ -3184,17 +3184,22 @@ activate_new(pcap_t *handle)
        handle->bufsize = handle->snapshot;
 
        /*
-        * Only enable the insertion of VLAN tags if the link-layer
-        * header type is Ethernet.  If it should be supported on
-        * any other link-layer type, the code that inserts them
-        * must be modified to insert them in the proper place, which
-        * differs from link-layer header type to link-layer header
-        * type.
+        * Set the offset at which to insert VLAN tags.
         */
-       if (handle->linktype == DLT_EN10MB)
-               handle->md.add_vlan_tags = 1;
-       else
-               handle->md.add_vlan_tags = 0;
+       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;
@@ -3283,14 +3288,6 @@ activate_mmap(pcap_t *handle, int *status)
        handle->getnonblock_op = pcap_getnonblock_mmap;
        handle->oneshot_callback = pcap_oneshot_mmap;
        handle->selectable_fd = handle->fd;
-
-       /*
-        * We only support inserting VLAN tags for tpacket V2;
-        * if we're using v1, disable it.
-        */
-       if (handle->md.tp_version == TPACKET_V1)
-               handle->md.add_vlan_tags = 0;
-
        return 1;
 }
 #else /* HAVE_PACKET_RING */
@@ -4043,14 +4040,15 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback,
                }
 
 #ifdef HAVE_TPACKET2
-               if (handle->md.add_vlan_tags && h.h2->tp_vlan_tci &&
-                   tp_snaplen >= 2 * ETH_ALEN) {
+               if (handle->md.tp_version == TPACKET_V2 && h.h2->tp_vlan_tci &&
+                   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);
 
@@ -5237,9 +5235,10 @@ activate_old(pcap_t *handle)
        handle->offset   = 0;
 
        /*
-        * No support for getting VLAN tags to insert.
+        * SOCK_PACKET sockets don't supply information from
+        * stripped VLAN tags.
         */
-       handle->md.add_vlan_tags = 0;
+       handle->md.vlan_offset = -1; /* unknown */
 
        return 1;
 }