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sctp: improve consistency in handling chunks with wrong size

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Just skip the chunk, if no other handling is required by the
specification.
This commit is contained in:
Michael Tuexen 2021-04-28 18:09:11 +02:00
parent 420d30f5bd
commit 9de7354bb8
1 changed files with 77 additions and 79 deletions
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156
sys/netinet/sctp_input.c
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@ -4294,6 +4294,7 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
int ret;
int abort_no_unlock = 0;
int ecne_seen = 0;
int abort_flag;
/*
* How big should this be, and should it be alloc'd? Lets try the
@ -4773,8 +4774,7 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_HEARTBEAT_ACK\n");
if ((stcb == NULL) || (chk_length != sizeof(struct sctp_heartbeat_chunk))) {
/* Its not ours */
*offset = length;
return (stcb);
break;
}
SCTP_STAT_INCR(sctps_recvheartbeatack);
if ((netp != NULL) && (*netp != NULL)) {
@ -4800,12 +4800,10 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_SHUTDOWN, stcb %p\n",
(void *)stcb);
if ((stcb == NULL) || (chk_length != sizeof(struct sctp_shutdown_chunk))) {
*offset = length;
return (stcb);
break;
}
if ((netp != NULL) && (*netp != NULL)) {
int abort_flag = 0;
abort_flag = 0;
sctp_handle_shutdown((struct sctp_shutdown_chunk *)ch,
stcb, *netp, &abort_flag);
if (abort_flag) {
@ -4956,7 +4954,7 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
case SCTP_COOKIE_ACK:
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_COOKIE_ACK, stcb %p\n", (void *)stcb);
if ((stcb == NULL) || chk_length != sizeof(struct sctp_cookie_ack_chunk)) {
return (stcb);
break;
}
if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
/* We are not interested anymore */
@ -4975,26 +4973,29 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
break;
case SCTP_ECN_ECHO:
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ECN_ECHO\n");
if ((stcb == NULL) || (chk_length != sizeof(struct sctp_ecne_chunk))) {
/* Its not ours */
*offset = length;
return (stcb);
if (stcb == NULL) {
break;
}
if (stcb->asoc.ecn_supported == 0) {
goto unknown_chunk;
}
if (chk_length != sizeof(struct sctp_ecne_chunk)) {
break;
}
sctp_handle_ecn_echo((struct sctp_ecne_chunk *)ch, stcb);
ecne_seen = 1;
break;
case SCTP_ECN_CWR:
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ECN_CWR\n");
if ((stcb == NULL) || (chk_length != sizeof(struct sctp_cwr_chunk))) {
*offset = length;
return (stcb);
if (stcb == NULL) {
break;
}
if (stcb->asoc.ecn_supported == 0) {
goto unknown_chunk;
}
if (chk_length != sizeof(struct sctp_cwr_chunk)) {
break;
}
sctp_handle_ecn_cwr((struct sctp_cwr_chunk *)ch, stcb, *netp);
break;
case SCTP_SHUTDOWN_COMPLETE:
@ -5025,15 +5026,16 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
break;
case SCTP_ASCONF_ACK:
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ASCONF_ACK\n");
if (chk_length < sizeof(struct sctp_asconf_ack_chunk)) {
/* Its not ours */
*offset = length;
return (stcb);
if (stcb == NULL) {
break;
}
if ((stcb != NULL) && (netp != NULL) && (*netp != NULL)) {
if (stcb->asoc.asconf_supported == 0) {
goto unknown_chunk;
}
if (stcb->asoc.asconf_supported == 0) {
goto unknown_chunk;
}
if (chk_length < sizeof(struct sctp_asconf_ack_chunk)) {
break;
}
if ((netp != NULL) && (*netp != NULL)) {
/* He's alive so give him credit */
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
@ -5053,61 +5055,58 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
case SCTP_IFORWARD_CUM_TSN:
SCTPDBG(SCTP_DEBUG_INPUT3, "%s\n",
ch->chunk_type == SCTP_FORWARD_CUM_TSN ? "FORWARD_TSN" : "I_FORWARD_TSN");
if (chk_length < sizeof(struct sctp_forward_tsn_chunk)) {
/* Its not ours */
*offset = length;
return (stcb);
if (stcb == NULL) {
break;
}
if (stcb != NULL) {
int abort_flag = 0;
if (stcb->asoc.prsctp_supported == 0) {
goto unknown_chunk;
}
if (((stcb->asoc.idata_supported == 1) && (ch->chunk_type == SCTP_FORWARD_CUM_TSN)) ||
((stcb->asoc.idata_supported == 0) && (ch->chunk_type == SCTP_IFORWARD_CUM_TSN))) {
if (ch->chunk_type == SCTP_FORWARD_CUM_TSN) {
SCTP_SNPRINTF(msg, sizeof(msg), "%s", "FORWARD-TSN chunk received when I-FORWARD-TSN was negotiated");
} else {
SCTP_SNPRINTF(msg, sizeof(msg), "%s", "I-FORWARD-TSN chunk received when FORWARD-TSN was negotiated");
}
op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
sctp_abort_an_association(inp, stcb, op_err, SCTP_SO_NOT_LOCKED);
*offset = length;
return (NULL);
}
*fwd_tsn_seen = 1;
if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
/* We are not interested anymore */
(void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
SCTP_FROM_SCTP_INPUT + SCTP_LOC_31);
*offset = length;
return (NULL);
}
/*
* For sending a SACK this looks like DATA
* chunks.
*/
stcb->asoc.last_data_chunk_from = stcb->asoc.last_control_chunk_from;
sctp_handle_forward_tsn(stcb,
(struct sctp_forward_tsn_chunk *)ch, &abort_flag, m, *offset);
if (abort_flag) {
*offset = length;
return (NULL);
if (stcb->asoc.prsctp_supported == 0) {
goto unknown_chunk;
}
if (chk_length < sizeof(struct sctp_forward_tsn_chunk)) {
break;
}
if (((stcb->asoc.idata_supported == 1) && (ch->chunk_type == SCTP_FORWARD_CUM_TSN)) ||
((stcb->asoc.idata_supported == 0) && (ch->chunk_type == SCTP_IFORWARD_CUM_TSN))) {
if (ch->chunk_type == SCTP_FORWARD_CUM_TSN) {
SCTP_SNPRINTF(msg, sizeof(msg), "%s", "FORWARD-TSN chunk received when I-FORWARD-TSN was negotiated");
} else {
SCTP_SNPRINTF(msg, sizeof(msg), "%s", "I-FORWARD-TSN chunk received when FORWARD-TSN was negotiated");
}
op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
sctp_abort_an_association(inp, stcb, op_err, SCTP_SO_NOT_LOCKED);
*offset = length;
return (NULL);
}
*fwd_tsn_seen = 1;
if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
/* We are not interested anymore */
(void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
SCTP_FROM_SCTP_INPUT + SCTP_LOC_31);
*offset = length;
return (NULL);
}
/*
* For sending a SACK this looks like DATA chunks.
*/
stcb->asoc.last_data_chunk_from = stcb->asoc.last_control_chunk_from;
abort_flag = 0;
sctp_handle_forward_tsn(stcb,
(struct sctp_forward_tsn_chunk *)ch, &abort_flag, m, *offset);
if (abort_flag) {
*offset = length;
return (NULL);
}
break;
case SCTP_STREAM_RESET:
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_STREAM_RESET\n");
if ((stcb == NULL) || (chk_length < sizeof(struct sctp_stream_reset_tsn_req))) {
/* Its not ours */
*offset = length;
return (stcb);
if (stcb == NULL) {
break;
}
if (stcb->asoc.reconfig_supported == 0) {
goto unknown_chunk;
}
if (chk_length < sizeof(struct sctp_stream_reset_tsn_req)) {
break;
}
if (sctp_handle_stream_reset(stcb, m, *offset, ch)) {
/* stop processing */
*offset = length;
@ -5116,17 +5115,16 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
break;
case SCTP_PACKET_DROPPED:
SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_PACKET_DROPPED\n");
/* re-get it all please */
if (chk_length < sizeof(struct sctp_pktdrop_chunk)) {
/* Its not ours */
*offset = length;
return (stcb);
if (stcb == NULL) {
break;
}
if ((stcb != NULL) && (netp != NULL) && (*netp != NULL)) {
if (stcb->asoc.pktdrop_supported == 0) {
goto unknown_chunk;
}
if (stcb->asoc.pktdrop_supported == 0) {
goto unknown_chunk;
}
if (chk_length < sizeof(struct sctp_pktdrop_chunk)) {
break;
}
if ((netp != NULL) && (*netp != NULL)) {
sctp_handle_packet_dropped((struct sctp_pktdrop_chunk *)ch,
stcb, *netp,
min(chk_length, contiguous));
@ -5142,7 +5140,7 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
auth_skipped = 1;
}
/* skip this chunk (temporarily) */
goto next_chunk;
break;
}
if (stcb->asoc.auth_supported == 0) {
goto unknown_chunk;
@ -5156,7 +5154,7 @@ sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
}
if (got_auth == 1) {
/* skip this chunk... it's already auth'd */
goto next_chunk;
break;
}
got_auth = 1;
if (sctp_handle_auth(stcb, (struct sctp_auth_chunk *)ch, m, *offset)) {