pimd: add support for IGMPv2

Signed-off-by: Daniel Walton <dwalton@cumulusnetworks.com>

Ticket: CM-7962

1 files changed, 190 insertions, 0 deletions

diff --git a/pimd/pim_igmpv2.c b/pimd/pim_igmpv2.c
new file mode 100644
index 000000000..cc78f18d7
--- /dev/null
+++ b/pimd/pim_igmpv2.c
@@ -0,0 +1,190 @@
+/*
+ * PIM for Quagga
+ * Copyright (C) 2016 Cumulus Networks, Inc.
+ * Daniel Walton
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include "pimd.h"
+#include "pim_igmp.h"
+#include "pim_igmpv2.h"
+#include "pim_igmpv3.h"
+#include "pim_str.h"
+#include "pim_time.h"
+#include "pim_util.h"
+
+
+static void
+on_trace (const char *label,
+          struct interface *ifp, struct in_addr from)
+{
+  if (PIM_DEBUG_IGMP_TRACE) {
+    char from_str[100];
+    pim_inet4_dump("<from?>", from, from_str, sizeof(from_str));
+    zlog_debug("%s: from %s on %s",
+               label, from_str, ifp->name);
+  }
+}
+
+void
+igmp_v2_send_query (struct igmp_group *group,
+                    int fd,
+                    const char *ifname,
+                    char *query_buf,
+                    struct in_addr dst_addr,
+                    struct in_addr group_addr,
+                    int query_max_response_time_dsec)
+{
+  ssize_t             msg_size = 8;
+  uint8_t             max_resp_code;
+  ssize_t             sent;
+  struct sockaddr_in  to;
+  socklen_t           tolen;
+  uint16_t            checksum;
+
+  /* max_resp_code must be non-zero else this will look like an IGMP v1 query */
+  max_resp_code = igmp_msg_encode16to8(query_max_response_time_dsec);
+  zassert(max_resp_code > 0);
+
+  query_buf[0] = PIM_IGMP_MEMBERSHIP_QUERY;
+  query_buf[1] = max_resp_code;
+  *(uint16_t *)(query_buf + IGMP_CHECKSUM_OFFSET)   = 0; /* for computing checksum */
+  memcpy(query_buf+4, &group_addr, sizeof(struct in_addr));
+
+  checksum = in_cksum(query_buf, msg_size);
+  *(uint16_t *)(query_buf + IGMP_CHECKSUM_OFFSET) = checksum;
+
+  if (PIM_DEBUG_IGMP_PACKETS) {
+    char dst_str[100];
+    char group_str[100];
+    pim_inet4_dump("<dst?>", dst_addr, dst_str, sizeof(dst_str));
+    pim_inet4_dump("<group?>", group_addr, group_str, sizeof(group_str));
+    zlog_debug("Send IGMPv2 QUERY to %s on %s for group %s",
+	       dst_str, ifname, group_str);
+  }
+
+  memset(&to, 0, sizeof(to));
+  to.sin_family = AF_INET;
+  to.sin_addr = dst_addr;
+  tolen = sizeof(to);
+
+  sent = sendto(fd, query_buf, msg_size, MSG_DONTWAIT,
+                (struct sockaddr *)&to, tolen);
+  if (sent != (ssize_t) msg_size) {
+    char dst_str[100];
+    char group_str[100];
+    pim_inet4_dump("<dst?>", dst_addr, dst_str, sizeof(dst_str));
+    pim_inet4_dump("<group?>", group_addr, group_str, sizeof(group_str));
+    if (sent < 0) {
+      zlog_warn("Send IGMPv2 QUERY failed due to %s on %s: group=%s msg_size=%zd: errno=%d: %s",
+		dst_str, ifname, group_str, msg_size, errno, safe_strerror(errno));
+    }
+    else {
+      zlog_warn("Send IGMPv2 QUERY failed due to %s on %s: group=%s msg_size=%zd: sent=%zd",
+		dst_str, ifname, group_str, msg_size, sent);
+    }
+    return;
+  }
+}
+
+int
+igmp_v2_recv_report (struct igmp_sock *igmp,
+                     struct in_addr from, const char *from_str,
+                     char *igmp_msg, int igmp_msg_len)
+{
+  struct interface *ifp = igmp->interface;
+  struct in_addr group_addr;
+  char group_str[100];
+
+  on_trace(__PRETTY_FUNCTION__, igmp->interface, from);
+
+  if (igmp_msg_len != IGMP_V12_MSG_SIZE) {
+    zlog_warn("Recv IGMPv2 REPORT from %s on %s: size=%d other than correct=%d",
+              from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE);
+    return -1;
+  }
+
+  memcpy(&group_addr, igmp_msg + 4, sizeof(struct in_addr));
+
+  if (PIM_DEBUG_IGMP_PACKETS) {
+    pim_inet4_dump("<dst?>", group_addr, group_str, sizeof(group_str));
+    zlog_debug("Recv IGMPv2 REPORT from %s on %s for %s",
+               from_str, ifp->name, group_str);
+  }
+
+  /*
+   * RFC 3376
+   * 7.3.2. In the Presence of Older Version Group Members
+   *
+   * When Group Compatibility Mode is IGMPv2, a router internally
+   * translates the following IGMPv2 messages for that group to their
+   * IGMPv3 equivalents:
+   *
+   * IGMPv2 Message                IGMPv3 Equivalent
+   * --------------                -----------------
+   * Report                        IS_EX( {} )
+   * Leave                         TO_IN( {} )
+   */
+  igmpv3_report_isex (igmp, from, group_addr, 0, NULL, 1);
+
+  return 0;
+}
+
+int
+igmp_v2_recv_leave (struct igmp_sock *igmp,
+                    struct in_addr from, const char *from_str,
+                    char *igmp_msg, int igmp_msg_len)
+{
+  struct interface *ifp = igmp->interface;
+  struct in_addr group_addr;
+  char group_str[100];
+
+  on_trace(__PRETTY_FUNCTION__, igmp->interface, from);
+
+  if (igmp_msg_len != IGMP_V12_MSG_SIZE) {
+    zlog_warn("Recv IGMPv2 LEAVE from %s on %s: size=%d other than correct=%d",
+              from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE);
+    return -1;
+  }
+
+  memcpy(&group_addr, igmp_msg + 4, sizeof(struct in_addr));
+
+  if (PIM_DEBUG_IGMP_PACKETS) {
+    pim_inet4_dump("<dst?>", group_addr, group_str, sizeof(group_str));
+    zlog_debug("Recv IGMPv2 LEAVE from %s on %s for %s",
+               from_str, ifp->name, group_str);
+  }
+
+  memcpy(&group_addr, igmp_msg + 4, sizeof(struct in_addr));
+
+  /*
+   * RFC 3376
+   * 7.3.2. In the Presence of Older Version Group Members
+   *
+   * When Group Compatibility Mode is IGMPv2, a router internally
+   * translates the following IGMPv2 messages for that group to their
+   * IGMPv3 equivalents:
+   *
+   * IGMPv2 Message                IGMPv3 Equivalent
+   * --------------                -----------------
+   * Report                        IS_EX( {} )
+   * Leave                         TO_IN( {} )
+   */
+  igmpv3_report_toin (igmp, from, group_addr, 0, NULL);
+
+  return 0;
+}