diff options
Diffstat (limited to 'net/sctp/sm_make_chunk.c')
| -rw-r--r-- | net/sctp/sm_make_chunk.c | 86 |
1 files changed, 66 insertions, 20 deletions
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 0fd5b4c88358..bd2a50b482ac 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -108,7 +108,7 @@ static const struct sctp_paramhdr prsctp_param = { 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. */ @@ -125,6 +125,29 @@ void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 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 @@ -422,10 +445,17 @@ struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, if (!retval) goto nomem_chunk; - /* Per the advice in RFC 2960 6.4, send this reply to - * the source of the INIT packet. + /* RFC 2960 6.4 Multi-homed SCTP Endpoints + * + * An endpoint SHOULD transmit reply chunks (e.g., SACK, + * HEARTBEAT ACK, * etc.) to the same destination transport + * address from which it received the DATA or control chunk + * to which it is replying. + * + * [INIT ACK back to where the INIT came from.] */ retval->transport = chunk->transport; + retval->subh.init_hdr = sctp_addto_chunk(retval, sizeof(initack), &initack); retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); @@ -464,18 +494,6 @@ struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, /* We need to remove the const qualifier at this point. */ retval->asoc = (struct sctp_association *) asoc; - /* RFC 2960 6.4 Multi-homed SCTP Endpoints - * - * An endpoint SHOULD transmit reply chunks (e.g., SACK, - * HEARTBEAT ACK, * etc.) to the same destination transport - * address from which it received the DATA or control chunk - * to which it is replying. - * - * [INIT ACK back to where the INIT came from.] - */ - if (chunk) - retval->transport = chunk->transport; - nomem_chunk: kfree(cookie); nomem_cookie: @@ -1132,6 +1150,24 @@ 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, @@ -1213,7 +1249,6 @@ struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, INIT_LIST_HEAD(&retval->list); retval->skb = skb; retval->asoc = (struct sctp_association *)asoc; - retval->resent = 0; retval->has_tsn = 0; retval->has_ssn = 0; retval->rtt_in_progress = 0; @@ -1374,6 +1409,18 @@ void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 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. @@ -1977,13 +2024,12 @@ static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, * 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 { |