When sending in ICMP response to an SCTP packet,

* include the SCTP common header, if possible
* include the first 8 bytes of the INIT chunk, if possible
This provides the necesary information for the receiver of the ICMP
packet to process it.

MFC after:	1 week
This commit is contained in:
Michael Tuexen 2016-05-25 22:16:11 +00:00
parent d38447b51d
commit f88d0cfe7a

View File

@ -61,6 +61,7 @@ __FBSDID("$FreeBSD$");
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <netinet/ip_options.h>
#include <netinet/sctp.h>
#include <netinet/tcp.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
@ -249,6 +250,34 @@ icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu)
goto freeit;
icmpelen = max(tcphlen, min(V_icmp_quotelen,
ntohs(oip->ip_len) - oiphlen));
} else if (oip->ip_p == IPPROTO_SCTP) {
struct sctphdr *sh;
struct sctp_chunkhdr *ch;
if (ntohs(oip->ip_len) < oiphlen + sizeof(struct sctphdr))
goto stdreply;
if (oiphlen + sizeof(struct sctphdr) > n->m_len &&
n->m_next == NULL)
goto stdreply;
if (n->m_len < oiphlen + sizeof(struct sctphdr) &&
(n = m_pullup(n, oiphlen + sizeof(struct sctphdr))) == NULL)
goto freeit;
icmpelen = max(sizeof(struct sctphdr),
min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen));
sh = (struct sctphdr *)((caddr_t)oip + oiphlen);
if (ntohl(sh->v_tag) == 0 &&
ntohs(oip->ip_len) >= oiphlen + sizeof(struct sctphdr) + 8 &&
(n->m_len >= oiphlen + sizeof(struct sctphdr) + 8 ||
n->m_next != NULL)) {
if (n->m_len < oiphlen + sizeof(struct sctphdr) + 8 &&
(n = m_pullup(n, oiphlen + sizeof(struct sctphdr) + 8)) == NULL)
goto freeit;
ch = (struct sctp_chunkhdr *)(sh + 1);
if (ch->chunk_type == SCTP_INITIATION) {
icmpelen = max(sizeof(struct sctphdr) + 8,
min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen));
}
}
} else
stdreply: icmpelen = max(8, min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen));