git.openwrt.org Git - openwrt/staging/981213.git/blob

   1 From 65f777e7f66b55239d935c1cf81bb5abc0f6c89f Mon Sep 17 00:00:00 2001
   2 From: Grinch <grinch79@users.sourceforge.net>
   3 Date: Sun, 16 Aug 2009 19:58:26 +0500
   4 Subject: [PATCH] Restrict igmp reports for downstream interfaces (wrt #2833339)
   5
   6 atm all igmp membership reports are forwarded to the upstream interface.
   7 Unfortunately some ISP Providers restrict some multicast groups (esp. those
   8 that are defined as local link groups and that are not supposed to be
   9 forwarded to the wan, i.e 224.0.0.0/24). Therefore there should be some
  10 kind of black oder whitelisting.
  11 As whitelisting can be accomplished quite easy I wrote a litte patch, which
  12 is attached to this request.
  13 ---
  14  doc/igmpproxy.conf.5.in |   19 +++++++++++++++++++
  15  src/config.c            |   23 ++++++++++++++++++++++-
  16  src/igmpproxy.h         |    1 +
  17  src/request.c           |   20 ++++++++++++++++----
  18  4 files changed, 58 insertions(+), 5 deletions(-)
  19
  20 diff --git a/doc/igmpproxy.conf.5.in b/doc/igmpproxy.conf.5.in
  21 index a4ea7d0..56efa22 100644
  22 --- a/doc/igmpproxy.conf.5.in
  23 +++ b/doc/igmpproxy.conf.5.in
  24 @@ -116,6 +116,25 @@ This is especially useful for the upstream interface, since the source for multi
  25  traffic is often from a remote location. Any number of altnet parameters can be specified.
  26  .RE
  27
  28 +.B whitelist
  29 +.I networkaddr
  30 +.RS
  31 +Defines a whitelist for multicast groups. The network address must be in the following
  32 +format 'a.b.c.d/n'. If you want to allow one single group use a network mask of /32,
  33 +i.e. 'a.b.c.d/32'.
  34 +
  35 +By default all multicast groups are allowed on any downstream interface. If at least one
  36 +whitelist entry is defined, all igmp membership reports for not explicitly whitelisted
  37 +multicast groups will be ignored and therefore not be served by igmpproxy. This is especially
  38 +useful, if your provider does only allow a predefined set of multicast groups. These whitelists
  39 +are only obeyed by igmpproxy itself, they won't prevent any other igmp client running on the
  40 +same machine as igmpproxy from requesting 'unallowed' multicast groups.
  41 +
  42 +You may specify as many whitelist entries as needed. Although you should keep it as simple as
  43 +possible, as this list is parsed for every membership report and therefore this increases igmp
  44 +response times. Often used or large groups should be defined first, as parsing ends as soon as
  45 +a group matches an entry.
  46 +.RE
  47
  48  .SH EXAMPLE
  49  ## Enable quickleave
  50 diff --git a/src/config.c b/src/config.c
  51 index 5a96ce0..d72619f 100644
  52 --- a/src/config.c
  53 +++ b/src/config.c
  54 @@ -46,6 +46,9 @@ struct vifconfig {
  55
  56      // Keep allowed nets for VIF.
  57      struct SubnetList*  allowednets;
  58 +
  59 +    // Allowed Groups
  60 +    struct SubnetList*  allowedgroups;
  61
  62      // Next config in list...
  63      struct vifconfig*   next;
  64 @@ -202,6 +205,8 @@ void configureVifs() {
  65                      // Insert the configured nets...
  66                      vifLast->next = confPtr->allowednets;
  67
  68 +                   Dp->allowedgroups = confPtr->allowedgroups;
  69 +
  70                      break;
  71                  }
  72              }
  73 @@ -215,7 +220,7 @@ void configureVifs() {
  74  */
  75  struct vifconfig *parsePhyintToken() {
  76      struct vifconfig  *tmpPtr;
  77 -    struct SubnetList **anetPtr;
  78 +    struct SubnetList **anetPtr, **agrpPtr;
  79      char *token;
  80      short parseError = 0;
  81
  82 @@ -239,6 +244,7 @@ struct vifconfig *parsePhyintToken() {
  83      tmpPtr->threshold = 1;
  84      tmpPtr->state = IF_STATE_DOWNSTREAM;
  85      tmpPtr->allowednets = NULL;
  86 +    tmpPtr->allowedgroups = NULL;
  87
  88      // Make a copy of the token to store the IF name
  89      tmpPtr->name = strdup( token );
  90 @@ -248,6 +254,7 @@ struct vifconfig *parsePhyintToken() {
  91
  92      // Set the altnet pointer to the allowednets pointer.
  93      anetPtr = &tmpPtr->allowednets;
  94 +    agrpPtr = &tmpPtr->allowedgroups;
  95
  96      // Parse the rest of the config..
  97      token = nextConfigToken();
  98 @@ -266,6 +273,20 @@ struct vifconfig *parsePhyintToken() {
  99                  anetPtr = &(*anetPtr)->next;
 100              }
 101          }
 102 +       else if(strcmp("whitelist", token)==0) {
 103 +           // Whitelist
 104 +           token = nextConfigToken();
 105 +           my_log(LOG_DEBUG, 0, "Config: IF: Got whitelist token %s.", token);
 106 +
 107 +           *agrpPtr = parseSubnetAddress(token);
 108 +           if(*agrpPtr == NULL) {
 109 +               parseError = 1;
 110 +               my_log(LOG_WARNING, 0, "Unable to parse subnet address.");
 111 +               break;
 112 +           } else {
 113 +               agrpPtr = &(*agrpPtr)->next;
 114 +           }
 115 +       }
 116          else if(strcmp("upstream", token)==0) {
 117              // Upstream
 118              my_log(LOG_DEBUG, 0, "Config: IF: Got upstream token.");
 119 diff --git a/src/igmpproxy.h b/src/igmpproxy.h
 120 index 4dabd1c..0de7791 100644
 121 --- a/src/igmpproxy.h
 122 +++ b/src/igmpproxy.h
 123 @@ -145,6 +145,7 @@ struct IfDesc {
 124      short               Flags;
 125      short               state;
 126      struct SubnetList*  allowednets;
 127 +    struct SubnetList*  allowedgroups;
 128      unsigned int        robustness;
 129      unsigned char       threshold;   /* ttl limit */
 130      unsigned int        ratelimit;
 131 diff --git a/src/request.c b/src/request.c
 132 index e3589f6..89b91de 100644
 133 --- a/src/request.c
 134 +++ b/src/request.c
 135 @@ -82,10 +82,22 @@ void acceptGroupReport(uint32_t src, uint32_t group, uint8_t type) {
 136          my_log(LOG_DEBUG, 0, "Should insert group %s (from: %s) to route table. Vif Ix : %d",
 137              inetFmt(group,s1), inetFmt(src,s2), sourceVif->index);
 138
 139 -        // The membership report was OK... Insert it into the route table..
 140 -        insertRoute(group, sourceVif->index);
 141 -
 142 -
 143 +       // If we don't have a whitelist we insertRoute and done
 144 +       if(sourceVif->allowedgroups == NULL)
 145 +       {
 146 +           insertRoute(group, sourceVif->index);
 147 +           return;
 148 +       }
 149 +       // Check if this Request is legit on this interface
 150 +       struct SubnetList *sn;
 151 +       for(sn = sourceVif->allowedgroups; sn != NULL; sn = sn->next)
 152 +           if((group & sn->subnet_mask) == sn->subnet_addr)
 153 +           {
 154 +               // The membership report was OK... Insert it into the route table..
 155 +               insertRoute(group, sourceVif->index);
 156 +               return;
 157 +           }
 158 +       my_log(LOG_INFO, 0, "The group address %s may not be requested from this interface. Ignoring.", inetFmt(group, s1));
 159      } else {
 160          // Log the state of the interface the report was recieved on.
 161          my_log(LOG_INFO, 0, "Mebership report was recieved on %s. Ignoring.",
 162 --
 163 1.7.2.5
 164