svn commit: r287669 - head/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Fri Sep 11 13:54:33 2015
New Revision: 287669
URL: https://svnweb.freebsd.org/changeset/base/287669

Log:
  Ensure that ERROR chunks are always padded by implementing this
  in the routine, which queues an ERROR chunk, instead on relyinh
  on the callers to do so. Since one caller missed this, this actially
  fixes a bug.
  
  MFC after:	1 week

Modified:
  head/sys/netinet/sctp_constants.h
  head/sys/netinet/sctp_indata.c
  head/sys/netinet/sctp_input.c
  head/sys/netinet/sctp_output.c

Modified: head/sys/netinet/sctp_constants.h
==============================================================================
--- head/sys/netinet/sctp_constants.h	Fri Sep 11 13:32:55 2015	(r287668)
+++ head/sys/netinet/sctp_constants.h	Fri Sep 11 13:54:33 2015	(r287669)
@@ -66,6 +66,8 @@ __FBSDID("$FreeBSD$");
  */
 #define SCTP_LARGEST_INIT_ACCEPTED (65535 - 2048)
 
+/* Largest length of a chunk */
+#define SCTP_MAX_CHUNK_LENGTH 0xffff
 /* Number of addresses where we just skip the counting */
 #define SCTP_COUNT_LIMIT 40
 

Modified: head/sys/netinet/sctp_indata.c
==============================================================================
--- head/sys/netinet/sctp_indata.c	Fri Sep 11 13:32:55 2015	(r287668)
+++ head/sys/netinet/sctp_indata.c	Fri Sep 11 13:54:33 2015	(r287669)
@@ -2513,11 +2513,7 @@ sctp_process_data(struct mbuf **mm, int 
 						SCTP_BUF_LEN(merr) = sizeof(*phd);
 						SCTP_BUF_NEXT(merr) = SCTP_M_COPYM(m, *offset, chk_length, M_NOWAIT);
 						if (SCTP_BUF_NEXT(merr)) {
-							if (sctp_pad_lastmbuf(SCTP_BUF_NEXT(merr), SCTP_SIZE32(chk_length) - chk_length, NULL) == NULL) {
-								sctp_m_freem(merr);
-							} else {
-								sctp_queue_op_err(stcb, merr);
-							}
+							sctp_queue_op_err(stcb, merr);
 						} else {
 							sctp_m_freem(merr);
 						}

Modified: head/sys/netinet/sctp_input.c
==============================================================================
--- head/sys/netinet/sctp_input.c	Fri Sep 11 13:32:55 2015	(r287668)
+++ head/sys/netinet/sctp_input.c	Fri Sep 11 13:54:33 2015	(r287669)
@@ -5602,16 +5602,12 @@ process_control_chunks:
 					SCTP_BUF_LEN(mm) = sizeof(*phd);
 					SCTP_BUF_NEXT(mm) = SCTP_M_COPYM(m, *offset, len, M_NOWAIT);
 					if (SCTP_BUF_NEXT(mm)) {
-						if (sctp_pad_lastmbuf(SCTP_BUF_NEXT(mm), SCTP_SIZE32(len) - len, NULL) == NULL) {
-							sctp_m_freem(mm);
-						} else {
 #ifdef SCTP_MBUF_LOGGING
-							if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
-								sctp_log_mbc(SCTP_BUF_NEXT(mm), SCTP_MBUF_ICOPY);
-							}
-#endif
-							sctp_queue_op_err(stcb, mm);
+						if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
+							sctp_log_mbc(SCTP_BUF_NEXT(mm), SCTP_MBUF_ICOPY);
 						}
+#endif
+						sctp_queue_op_err(stcb, mm);
 					} else {
 						sctp_m_freem(mm);
 					}

Modified: head/sys/netinet/sctp_output.c
==============================================================================
--- head/sys/netinet/sctp_output.c	Fri Sep 11 13:32:55 2015	(r287668)
+++ head/sys/netinet/sctp_output.c	Fri Sep 11 13:54:33 2015	(r287669)
@@ -8850,9 +8850,37 @@ sctp_queue_op_err(struct sctp_tcb *stcb,
 	 */
 	struct sctp_chunkhdr *hdr;
 	struct sctp_tmit_chunk *chk;
-	struct mbuf *mat;
+	struct mbuf *mat, *last_mbuf;
+	uint32_t chunk_length;
+	uint16_t padding_length;
 
 	SCTP_TCB_LOCK_ASSERT(stcb);
+	SCTP_BUF_PREPEND(op_err, sizeof(struct sctp_chunkhdr), M_NOWAIT);
+	if (op_err == NULL) {
+		return;
+	}
+	last_mbuf = NULL;
+	chunk_length = 0;
+	for (mat = op_err; mat != NULL; mat = SCTP_BUF_NEXT(mat)) {
+		chunk_length += SCTP_BUF_LEN(mat);
+		if (SCTP_BUF_NEXT(mat) == NULL) {
+			last_mbuf = mat;
+		}
+	}
+	if (chunk_length > SCTP_MAX_CHUNK_LENGTH) {
+		sctp_m_freem(op_err);
+		return;
+	}
+	padding_length = chunk_length % 4;
+	if (padding_length != 0) {
+		padding_length = 4 - padding_length;
+	}
+	if (padding_length != 0) {
+		if (sctp_add_pad_tombuf(last_mbuf, padding_length) == NULL) {
+			sctp_m_freem(op_err);
+			return;
+		}
+	}
 	sctp_alloc_a_chunk(stcb, chk);
 	if (chk == NULL) {
 		/* no memory */
@@ -8860,15 +8888,7 @@ sctp_queue_op_err(struct sctp_tcb *stcb,
 		return;
 	}
 	chk->copy_by_ref = 0;
-	SCTP_BUF_PREPEND(op_err, sizeof(struct sctp_chunkhdr), M_NOWAIT);
-	if (op_err == NULL) {
-		sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
-		return;
-	}
-	chk->send_size = 0;
-	for (mat = op_err; mat != NULL; mat = SCTP_BUF_NEXT(mat)) {
-		chk->send_size += SCTP_BUF_LEN(mat);
-	}
+	chk->send_size = (uint16_t) chunk_length;
 	chk->sent = SCTP_DATAGRAM_UNSENT;
 	chk->snd_count = 0;
 	chk->asoc = &stcb->asoc;
@@ -8878,9 +8898,7 @@ sctp_queue_op_err(struct sctp_tcb *stcb,
 	hdr->chunk_type = SCTP_OPERATION_ERROR;
 	hdr->chunk_flags = 0;
 	hdr->chunk_length = htons(chk->send_size);
-	TAILQ_INSERT_TAIL(&chk->asoc->control_send_queue,
-	    chk,
-	    sctp_next);
+	TAILQ_INSERT_TAIL(&chk->asoc->control_send_queue, chk, sctp_next);
 	chk->asoc->ctrl_queue_cnt++;
 }