libpcap-any/20-fix-any-intf.diff

   1 commit 8fa17a5a554aaeb85d3ec4118b45a31f1efd6808
   2 Author: guy <guy>
   3 Date:   Wed Nov 19 08:20:39 2008 +0000
   4
   5     Fix the handling of the "any" device, including making it reject
   6     attempts to open it in monitor mode.
   7 ---
   8  pcap-linux.c |   68 ++++++++++++++++++++++++++++++++++++-----------------------
   9  1 file changed, 42 insertions(+), 26 deletions(-)
  10
  11 --- a/pcap-linux.c
  12 +++ b/pcap-linux.c
  13 @@ -297,6 +297,12 @@
  14  {
  15         pcap_t *handle;
  16
  17 +       /*
  18 +        * A null device name is equivalent to the "any" device.
  19 +        */
  20 +       if (device == NULL)
  21 +               device = "any";
  22 +
  23  #ifdef HAVE_DAG_API
  24         if (strstr(device, "dag")) {
  25                 return dag_create(device, ebuf);
  26 @@ -338,10 +344,9 @@
  27         struct iwreq ireq;
  28  #endif
  29
  30 -       if (p->opt.source == NULL) {
  31 +       if (strcmp(p->opt.source, "any") == 0) {
  32                 /*
  33 -                * This is equivalent to the "any" device, and we don't
  34 -                * support monitor mode on it.
  35 +                * Monitor mode makes no sense on the "any" device.
  36                  */
  37                 return 0;
  38         }
  39 @@ -518,12 +523,11 @@
  40         handle->stats_op = pcap_stats_linux;
  41
  42         /*
  43 -        * NULL and "any" are special devices which give us the hint to
  44 -        * monitor all devices.
  45 +        * The "any" device is a special device which causes us not
  46 +        * to bind to a particular device and thus to look at all
  47 +        * devices.
  48          */
  49 -       if (!device || strcmp(device, "any") == 0) {
  50 -               device                  = NULL;
  51 -               handle->md.device       = strdup("any");
  52 +       if (strcmp(device, "any") == 0) {
  53                 if (handle->opt.promisc) {
  54                         handle->opt.promisc = 0;
  55                         /* Just a warning. */
  56 @@ -531,10 +535,9 @@
  57                             "Promiscuous mode not supported on the \"any\" device");
  58                         status = PCAP_WARNING_PROMISC_NOTSUP;
  59                 }
  60 +       }
  61
  62 -       } else
  63 -               handle->md.device       = strdup(device);
  64 -
  65 +       handle->md.device       = strdup(device);
  66         if (handle->md.device == NULL) {
  67                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s",
  68                          pcap_strerror(errno) );
  69 @@ -1657,19 +1660,21 @@
  70  activate_new(pcap_t *handle)
  71  {
  72  #ifdef HAVE_PF_PACKET_SOCKETS
  73 +       const char              *device = handle->opt.source;
  74 +       int                     is_any_device = (strcmp(device, "any") == 0);
  75         int                     sock_fd = -1, arptype, val;
  76         int                     err = 0;
  77         struct packet_mreq      mr;
  78 -       const char* device = handle->opt.source;
  79
  80         /*
  81 -        * Open a socket with protocol family packet. If a device is
  82 -        * given we try to open it in raw mode otherwise we use
  83 -        * the cooked interface.
  84 -        */
  85 -       sock_fd = device ?
  86 -               socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL))
  87 -             : socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL));
  88 +        * Open a socket with protocol family packet. If the
  89 +        * "any" device was specified, we open a SOCK_DGRAM
  90 +        * socket for the cooked interface, otherwise we first
  91 +        * try a SOCK_RAW socket for the raw interface.
  92 +        */
  93 +       sock_fd = is_any_device ?
  94 +               socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL)) :
  95 +               socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
  96
  97         if (sock_fd == -1) {
  98                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
  99 @@ -1704,7 +1709,7 @@
 100          * to cooked mode if we have an unknown interface type
 101          * or a type we know doesn't work well in raw mode.
 102          */
 103 -       if (device) {
 104 +       if (!is_any_device) {
 105                 /* Assume for now we don't need cooked mode. */
 106                 handle->md.cooked = 0;
 107
 108 @@ -1819,15 +1824,23 @@
 109                 }
 110         } else {
 111                 /*
 112 -                * This is cooked mode.
 113 +                * The "any" device.
 114 +                */
 115 +               if (handle->opt.rfmon) {
 116 +                       /*
 117 +                        * It doesn't support monitor mode.
 118 +                        */
 119 +                       return PCAP_ERROR_RFMON_NOTSUP;
 120 +               }
 121 +
 122 +               /*
 123 +                * It uses cooked mode.
 124                  */
 125                 handle->md.cooked = 1;
 126                 handle->linktype = DLT_LINUX_SLL;
 127
 128                 /*
 129                  * We're not bound to a device.
 130 -                * XXX - true?  Or true only if we're using
 131 -                * the "any" device?
 132                  * For now, we're using this as an indication
 133                  * that we can't transmit; stop doing that only
 134                  * if we figure out how to transmit in cooked
 135 @@ -1852,10 +1865,13 @@
 136
 137         /*
 138          * Hmm, how can we set promiscuous mode on all interfaces?
 139 -        * I am not sure if that is possible at all.
 140 +        * I am not sure if that is possible at all.  For now, we
 141 +        * silently ignore attempts to turn promiscuous mode on
 142 +        * for the "any" device (so you don't have to explicitly
 143 +        * disable it in programs such as tcpdump).
 144          */
 145
 146 -       if (device && handle->opt.promisc) {
 147 +       if (!is_any_device && handle->opt.promisc) {
 148                 memset(&mr, 0, sizeof(mr));
 149                 mr.mr_ifindex = handle->md.ifindex;
 150                 mr.mr_type    = PACKET_MR_PROMISC;
 151 @@ -3118,7 +3134,7 @@
 152
 153         /* Bind to the given device */
 154
 155 -       if (!device) {
 156 +       if (strcmp(device, "any") == 0) {
 157                 strncpy(handle->errbuf, "pcap_activate: The \"any\" device isn't supported on 2.0[.x]-kernel systems",
 158                         PCAP_ERRBUF_SIZE);
 159                 return PCAP_ERROR;