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When processing an ICMP packet containing an SCTP packet, it

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is required to check the verification tag. However, this
requires the verification tag to be not 0. Enforce this.
For packets with a verification tag of 0, we need to
check it it contains an INIT chunk and use the initiate
tag for the validation. This will be a separate commit,
since it touches also other code.

MFC after: 1 week
This commit is contained in:
Michael Tuexen 2016-04-12 11:48:54 +00:00
parent 003c82d713
commit cf4476eb39
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=297855
2 changed files with 31 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
sys/netinet/sctp_usrreq.c
View File

@ -147,26 +147,19 @@ static void
sctp_notify_mbuf(struct sctp_inpcb *inp,
struct sctp_tcb *stcb,
struct sctp_nets *net,
struct ip *ip,
struct sctphdr *sh)
struct ip *ip)
{
struct icmp *icmph;
int totsz, tmr_stopped = 0;
uint16_t nxtsz;
/* protection */
if ((inp == NULL) || (stcb == NULL) || (net == NULL) ||
(ip == NULL) || (sh == NULL)) {
if ((inp == NULL) || (stcb == NULL) || (net == NULL) || (ip == NULL)) {
if (stcb != NULL) {
SCTP_TCB_UNLOCK(stcb);
}
return;
}
/* First job is to verify the vtag matches what I would send */
if (ntohl(sh->v_tag) != (stcb->asoc.peer_vtag)) {
SCTP_TCB_UNLOCK(stcb);
return;
}
icmph = (struct icmp *)((caddr_t)ip - (sizeof(struct icmp) -
sizeof(struct ip)));
if (icmph->icmp_type != ICMP_UNREACH) {
@ -213,10 +206,9 @@ sctp_notify_mbuf(struct sctp_inpcb *inp,
SCTP_TCB_UNLOCK(stcb);
}
void
static void
sctp_notify(struct sctp_inpcb *inp,
struct ip *ip,
struct sctphdr *sh,
struct sockaddr *to,
struct sctp_tcb *stcb,
struct sctp_nets *net)
@ -228,17 +220,11 @@ sctp_notify(struct sctp_inpcb *inp,
struct icmp *icmph;
/* protection */
if ((inp == NULL) || (stcb == NULL) || (net == NULL) ||
(sh == NULL) || (to == NULL)) {
if ((inp == NULL) || (stcb == NULL) || (net == NULL) || (to == NULL)) {
if (stcb)
SCTP_TCB_UNLOCK(stcb);
return;
}
/* First job is to verify the vtag matches what I would send */
if (ntohl(sh->v_tag) != (stcb->asoc.peer_vtag)) {
SCTP_TCB_UNLOCK(stcb);
return;
}
icmph = (struct icmp *)((caddr_t)ip - (sizeof(struct icmp) -
sizeof(struct ip)));
if (icmph->icmp_type != ICMP_UNREACH) {
@ -304,10 +290,7 @@ sctp_notify(struct sctp_inpcb *inp,
#ifdef INET
void
sctp_ctlinput(cmd, sa, vip)
int cmd;
struct sockaddr *sa;
void *vip;
sctp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
{
struct ip *ip = vip;
struct sctphdr *sh;
@ -348,14 +331,37 @@ sctp_ctlinput(cmd, sa, vip)
stcb = sctp_findassociation_addr_sa((struct sockaddr *)&to,
(struct sockaddr *)&from,
&inp, &net, 1, vrf_id);
if (stcb != NULL && inp && (inp->sctp_socket != NULL)) {
if ((stcb != NULL) &&
(inp != NULL) &&
(inp->sctp_socket != NULL)) {
/* Check the verification tag */
if (ntohl(sh->v_tag) != 0) {
/*
* This must be the verification tag used
* for sending out packets. We don't
* consider packets reflecting the
* verification tag.
*/
if (ntohl(sh->v_tag) != (stcb->asoc.peer_vtag)) {
SCTP_TCB_UNLOCK(stcb);
return;
}
} else {
/*
* In this case we could check if we got an
* INIT chunk and if the initiate tag
* matches. But this is not there yet...
*/
SCTP_TCB_UNLOCK(stcb);
return;
}
if (cmd != PRC_MSGSIZE) {
sctp_notify(inp, ip, sh,
sctp_notify(inp, ip,
(struct sockaddr *)&to, stcb,
net);
} else {
/* handle possible ICMP size messages */
sctp_notify_mbuf(inp, stcb, net, ip, sh);
sctp_notify_mbuf(inp, stcb, net, ip);
}
} else {
if ((stcb == NULL) && (inp != NULL)) {

4
sys/netinet/sctp_var.h
View File

@ -344,10 +344,6 @@ void sctp_init(void);
void sctp_finish(void);
int sctp_flush(struct socket *, int);
int sctp_shutdown(struct socket *);
void
sctp_notify(struct sctp_inpcb *, struct ip *ip, struct sctphdr *,
struct sockaddr *, struct sctp_tcb *,
struct sctp_nets *);
int
sctp_bindx(struct socket *, int, struct sockaddr_storage *,
int, int, struct proc *);