pimd: Add check for pim join, hello and assert to drop pkts without all-pim-routers...

This is as per RFC. This is identified when conformance suite catched join.

RCA:
Packets were processed without checking allowed dest IP for that packet.

Fix:
Added check for dest IP
Converted this check to a function

Signed-off-by: Saravanan K <saravanank@vmware.com>

diff --git a/pimd/pim_pim.c b/pimd/pim_pim.c
index 8d7a921cf4db8ff6336f248d908c2325bf46ca24..a76fbed20338ad17919f96b61a1200b733fdf9c2 100644 (file)
--- a/pimd/pim_pim.c
+++ b/pimd/pim_pim.c
@@ -137,6 +137,18 @@ void pim_sock_delete(struct interface *ifp, const char *delete_message)
        sock_close(ifp);
 }
 
+/* For now check dst address for hello, assrt and join/prune is all pim rtr */
+static bool pim_pkt_dst_addr_ok(enum pim_msg_type type, in_addr_t addr)
+{
+       if ((type == PIM_MSG_TYPE_HELLO) || (type == PIM_MSG_TYPE_ASSERT)
+           || (type == PIM_MSG_TYPE_JOIN_PRUNE)) {
+               if (addr != qpim_all_pim_routers_addr.s_addr)
+                       return false;
+       }
+
+       return true;
+}
+
 int pim_pim_packet(struct interface *ifp, uint8_t *buf, size_t len)
 {
        struct ip *ip_hdr;
@@ -237,6 +249,21 @@ int pim_pim_packet(struct interface *ifp, uint8_t *buf, size_t len)
                }
        }
 
+       if (!pim_pkt_dst_addr_ok(header->type, ip_hdr->ip_dst.s_addr)) {
+               char dst_str[INET_ADDRSTRLEN];
+               char src_str[INET_ADDRSTRLEN];
+
+               pim_inet4_dump("<dst?>", ip_hdr->ip_dst, dst_str,
+                              sizeof(dst_str));
+               pim_inet4_dump("<src?>", ip_hdr->ip_src, src_str,
+                              sizeof(src_str));
+               zlog_warn(
+                       "%s: Ignoring Pkt. Unexpected IP destination %s for %s (Expected: all_pim_routers_addr) from %s",
+                       __func__, dst_str, pim_pim_msgtype2str(header->type),
+                       src_str);
+               return -1;
+       }
+
        switch (header->type) {
        case PIM_MSG_TYPE_HELLO:
                return pim_hello_recv(ifp, ip_hdr->ip_src,