Merge pull request #9074 from mobash-rasool/pim-fixes

pimd: IGMPv3 conformance fixes for invalid TTL and invalid TOS
This commit is contained in:
Donald Sharp 2021-07-20 12:29:53 -04:00 committed by GitHub
commit b57d3daeea
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 52 additions and 17 deletions

View File

@ -469,6 +469,45 @@ static int igmp_v1_recv_report(struct igmp_sock *igmp, struct in_addr from,
return 0;
}
bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, int igmp_msg_len,
int msg_type)
{
if (len < sizeof(*ip_hdr)) {
zlog_warn("IGMP packet size=%zu shorter than minimum=%zu", len,
sizeof(*ip_hdr));
return false;
}
if (igmp_msg_len < PIM_IGMP_MIN_LEN) {
zlog_warn("IGMP message size=%d shorter than minimum=%d",
igmp_msg_len, PIM_IGMP_MIN_LEN);
return false;
}
if ((msg_type != PIM_IGMP_MTRACE_RESPONSE)
&& (msg_type != PIM_IGMP_MTRACE_QUERY_REQUEST)) {
if (ip_hdr->ip_ttl != 1) {
zlog_warn(
"Recv IGMP packet with invalid ttl=%u, discarding the packet",
ip_hdr->ip_ttl);
return -1;
}
}
if ((msg_type == PIM_IGMP_V3_MEMBERSHIP_REPORT)
|| ((msg_type == PIM_IGMP_MEMBERSHIP_QUERY)
&& (igmp_msg_len >= IGMP_V3_SOURCES_OFFSET))) {
/* All IGMPv3 messages must be received with TOS set to 0xC0*/
if (ip_hdr->ip_tos != IPTOS_PREC_INTERNETCONTROL) {
zlog_warn("Received IGMP Packet with invalid TOS %u",
ip_hdr->ip_tos);
return -1;
}
}
return true;
}
int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
{
struct ip *ip_hdr;
@ -479,17 +518,8 @@ int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
char from_str[INET_ADDRSTRLEN];
char to_str[INET_ADDRSTRLEN];
if (len < sizeof(*ip_hdr)) {
zlog_warn("IGMP packet size=%zu shorter than minimum=%zu", len,
sizeof(*ip_hdr));
return -1;
}
ip_hdr = (struct ip *)buf;
pim_inet4_dump("<src?>", ip_hdr->ip_src, from_str, sizeof(from_str));
pim_inet4_dump("<dst?>", ip_hdr->ip_dst, to_str, sizeof(to_str));
ip_hlen = ip_hdr->ip_hl << 2; /* ip_hl gives length in 4-byte words */
if (ip_hlen > len) {
@ -501,15 +531,11 @@ int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
igmp_msg = buf + ip_hlen;
igmp_msg_len = len - ip_hlen;
if (igmp_msg_len < PIM_IGMP_MIN_LEN) {
zlog_warn("IGMP message size=%d shorter than minimum=%d",
igmp_msg_len, PIM_IGMP_MIN_LEN);
return -1;
}
msg_type = *igmp_msg;
pim_inet4_dump("<src?>", ip_hdr->ip_src, from_str, sizeof(from_str));
pim_inet4_dump("<dst?>", ip_hdr->ip_dst, to_str, sizeof(to_str));
if (PIM_DEBUG_IGMP_PACKETS) {
zlog_debug(
"Recv IGMP packet from %s to %s on %s: size=%zu ttl=%d msg_type=%d msg_size=%d",
@ -517,6 +543,14 @@ int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
msg_type, igmp_msg_len);
}
if (!pim_igmp_verify_header(ip_hdr, len, igmp_msg_len, msg_type)) {
zlog_warn(
"Recv IGMP packet from %s to %s on %s: size=%zu ttl=%u msg_type=%d msg_size=%d",
from_str, to_str, igmp->interface->name, len,
ip_hdr->ip_ttl, msg_type, igmp_msg_len);
return -1;
}
switch (msg_type) {
case PIM_IGMP_MEMBERSHIP_QUERY: {
int max_resp_code = igmp_msg[1];

View File

@ -116,7 +116,8 @@ void igmp_sock_delete(struct igmp_sock *igmp);
void igmp_sock_free(struct igmp_sock *igmp);
void igmp_sock_delete_all(struct interface *ifp);
int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len);
bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, int igmp_msg_len,
int msg_type);
void pim_igmp_general_query_on(struct igmp_sock *igmp);
void pim_igmp_general_query_off(struct igmp_sock *igmp);
void pim_igmp_other_querier_timer_on(struct igmp_sock *igmp);