--- net/sctp/sm_make_chunk.c
+++ net/sctp/sm_make_chunk.c
@@ -107,7 +107,7 @@ static const struct sctp_paramhdr prsctp
cpu_to_be16(sizeof(struct sctp_paramhdr)),
};
-/* A helper to initialize to initialize an op error inside a
+/* A helper to initialize an op error inside a
* provided chunk, as most cause codes will be embedded inside an
* abort chunk.
*/
@@ -124,6 +124,29 @@ void sctp_init_cause(struct sctp_chunk
chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
}
+/* A helper to initialize an op error inside a
+ * provided chunk, as most cause codes will be embedded inside an
+ * abort chunk. Differs from sctp_init_cause in that it won't oops
+ * if there isn't enough space in the op error chunk
+ */
+int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
+ size_t paylen)
+{
+ sctp_errhdr_t err;
+ __u16 len;
+
+ /* Cause code constants are now defined in network order. */
+ err.cause = cause_code;
+ len = sizeof(sctp_errhdr_t) + paylen;
+ err.length = htons(len);
+
+ if (skb_tailroom(chunk->skb) < len)
+ return -ENOSPC;
+ chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
+ sizeof(sctp_errhdr_t),
+ &err);
+ return 0;
+}
/* 3.3.2 Initiation (INIT) (1)
*
* This chunk is used to initiate a SCTP association between two
@@ -1125,6 +1148,24 @@ nodata:
return retval;
}
+/* Create an Operation Error chunk of a fixed size,
+ * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
+ * This is a helper function to allocate an error chunk for
+ * for those invalid parameter codes in which we may not want
+ * to report all the errors, if the incomming chunk is large
+ */
+static inline struct sctp_chunk *sctp_make_op_error_fixed(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ size_t size = asoc ? asoc->pathmtu : 0;
+
+ if (!size)
+ size = SCTP_DEFAULT_MAXSEGMENT;
+
+ return sctp_make_op_error_space(asoc, chunk, size);
+}
+
/* Create an Operation Error chunk. */
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
@@ -1365,6 +1406,18 @@ void *sctp_addto_chunk(struct sctp_chunk
return target;
}
+/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
+ * space in the chunk
+ */
+void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
+ int len, const void *data)
+{
+ if (skb_tailroom(chunk->skb) >= len)
+ return sctp_addto_chunk(chunk, len, data);
+ else
+ return NULL;
+}
+
/* Append bytes from user space to the end of a chunk. Will panic if
* chunk is not big enough.
* Returns a kernel err value.
@@ -1968,13 +2021,12 @@ static sctp_ierror_t sctp_process_unk_pa
* returning multiple unknown parameters.
*/
if (NULL == *errp)
- *errp = sctp_make_op_error_space(asoc, chunk,
- ntohs(chunk->chunk_hdr->length));
+ *errp = sctp_make_op_error_fixed(asoc, chunk);
if (*errp) {
- sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
+ sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
WORD_ROUND(ntohs(param.p->length)));
- sctp_addto_chunk(*errp,
+ sctp_addto_chunk_fixed(*errp,
WORD_ROUND(ntohs(param.p->length)),
param.v);
} else {
projects / ziggy471-frankenstein-kernel.git / blobdiff