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SCTP: Make sctp_verify_param return multiple indications.
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SCTP-AUTH and future ADD-IP updates have a requirement to
do additional verification of parameters and an ability to
ABORT the association if verification fails.  So, introduce
additional return code so that we can clear signal a required
action.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
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Vlad Yasevich committed Nov 9, 2007
1 parent d970dbf commit 7ab9080
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Showing 2 changed files with 77 additions and 74 deletions.
2 changes: 2 additions & 0 deletions include/net/sctp/constants.h
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Original file line number Diff line number Diff line change
Expand Up @@ -186,6 +186,8 @@ typedef enum {
SCTP_IERROR_AUTH_BAD_HMAC,
SCTP_IERROR_AUTH_BAD_KEYID,
SCTP_IERROR_PROTO_VIOLATION,
SCTP_IERROR_ERROR,
SCTP_IERROR_ABORT,
} sctp_ierror_t;


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149 changes: 75 additions & 74 deletions net/sctp/sm_make_chunk.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1788,9 +1788,14 @@ static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
sizeof(sctp_paramhdr_t);


/* This is a fatal error. Any accumulated non-fatal errors are
* not reported.
*/
if (*errp)
sctp_chunk_free(*errp);

/* Create an error chunk and fill it in with our payload. */
if (!*errp)
*errp = sctp_make_op_error_space(asoc, chunk, payload_len);
*errp = sctp_make_op_error_space(asoc, chunk, payload_len);

if (*errp) {
sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION,
Expand All @@ -1813,9 +1818,15 @@ static int sctp_process_hn_param(const struct sctp_association *asoc,
{
__u16 len = ntohs(param.p->length);

/* Make an ERROR chunk. */
if (!*errp)
*errp = sctp_make_op_error_space(asoc, chunk, len);
/* Processing of the HOST_NAME parameter will generate an
* ABORT. If we've accumulated any non-fatal errors, they
* would be unrecognized parameters and we should not include
* them in the ABORT.
*/
if (*errp)
sctp_chunk_free(*errp);

*errp = sctp_make_op_error_space(asoc, chunk, len);

if (*errp) {
sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
Expand Down Expand Up @@ -1862,56 +1873,40 @@ static void sctp_process_ext_param(struct sctp_association *asoc,
* taken if the processing endpoint does not recognize the
* Parameter Type.
*
* 00 - Stop processing this SCTP chunk and discard it,
* do not process any further chunks within it.
* 00 - Stop processing this parameter; do not process any further
* parameters within this chunk
*
* 01 - Stop processing this SCTP chunk and discard it,
* do not process any further chunks within it, and report
* the unrecognized parameter in an 'Unrecognized
* Parameter Type' (in either an ERROR or in the INIT ACK).
* 01 - Stop processing this parameter, do not process any further
* parameters within this chunk, and report the unrecognized
* parameter in an 'Unrecognized Parameter' ERROR chunk.
*
* 10 - Skip this parameter and continue processing.
*
* 11 - Skip this parameter and continue processing but
* report the unrecognized parameter in an
* 'Unrecognized Parameter Type' (in either an ERROR or in
* the INIT ACK).
* 'Unrecognized Parameter' ERROR chunk.
*
* Return value:
* 0 - discard the chunk
* 1 - continue with the chunk
* SCTP_IERROR_NO_ERROR - continue with the chunk
* SCTP_IERROR_ERROR - stop and report an error.
* SCTP_IERROR_NOMEME - out of memory.
*/
static int sctp_process_unk_param(const struct sctp_association *asoc,
union sctp_params param,
struct sctp_chunk *chunk,
struct sctp_chunk **errp)
static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
union sctp_params param,
struct sctp_chunk *chunk,
struct sctp_chunk **errp)
{
int retval = 1;
int retval = SCTP_IERROR_NO_ERROR;

switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
case SCTP_PARAM_ACTION_DISCARD:
retval = 0;
break;
case SCTP_PARAM_ACTION_DISCARD_ERR:
retval = 0;
/* Make an ERROR chunk, preparing enough room for
* returning multiple unknown parameters.
*/
if (NULL == *errp)
*errp = sctp_make_op_error_space(asoc, chunk,
ntohs(chunk->chunk_hdr->length));

if (*errp) {
sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
WORD_ROUND(ntohs(param.p->length)));
sctp_addto_chunk(*errp,
WORD_ROUND(ntohs(param.p->length)),
param.v);
}

retval = SCTP_IERROR_ERROR;
break;
case SCTP_PARAM_ACTION_SKIP:
break;
case SCTP_PARAM_ACTION_DISCARD_ERR:
retval = SCTP_IERROR_ERROR;
/* Fall through */
case SCTP_PARAM_ACTION_SKIP_ERR:
/* Make an ERROR chunk, preparing enough room for
* returning multiple unknown parameters.
Expand All @@ -1932,9 +1927,8 @@ static int sctp_process_unk_param(const struct sctp_association *asoc,
* to the peer and the association won't be
* established.
*/
retval = 0;
retval = SCTP_IERROR_NOMEM;
}

break;
default:
break;
Expand All @@ -1943,18 +1937,20 @@ static int sctp_process_unk_param(const struct sctp_association *asoc,
return retval;
}

/* Find unrecognized parameters in the chunk.
/* Verify variable length parameters
* Return values:
* 0 - discard the chunk
* 1 - continue with the chunk
* SCTP_IERROR_ABORT - trigger an ABORT
* SCTP_IERROR_NOMEM - out of memory (abort)
* SCTP_IERROR_ERROR - stop processing, trigger an ERROR
* SCTP_IERROR_NO_ERROR - continue with the chunk
*/
static int sctp_verify_param(const struct sctp_association *asoc,
union sctp_params param,
sctp_cid_t cid,
struct sctp_chunk *chunk,
struct sctp_chunk **err_chunk)
static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
union sctp_params param,
sctp_cid_t cid,
struct sctp_chunk *chunk,
struct sctp_chunk **err_chunk)
{
int retval = 1;
int retval = SCTP_IERROR_NO_ERROR;

/* FIXME - This routine is not looking at each parameter per the
* chunk type, i.e., unrecognized parameters should be further
Expand All @@ -1976,7 +1972,9 @@ static int sctp_verify_param(const struct sctp_association *asoc,

case SCTP_PARAM_HOST_NAME_ADDRESS:
/* Tell the peer, we won't support this param. */
return sctp_process_hn_param(asoc, param, chunk, err_chunk);
sctp_process_hn_param(asoc, param, chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
break;

case SCTP_PARAM_FWD_TSN_SUPPORT:
if (sctp_prsctp_enable)
Expand All @@ -1993,9 +1991,11 @@ static int sctp_verify_param(const struct sctp_association *asoc,
* cause 'Protocol Violation'.
*/
if (SCTP_AUTH_RANDOM_LENGTH !=
ntohs(param.p->length) - sizeof(sctp_paramhdr_t))
return sctp_process_inv_paramlength(asoc, param.p,
ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
sctp_process_inv_paramlength(asoc, param.p,
chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
}
break;

case SCTP_PARAM_CHUNKS:
Expand All @@ -2007,9 +2007,11 @@ static int sctp_verify_param(const struct sctp_association *asoc,
* INIT-ACK chunk if the sender wants to receive authenticated
* chunks. Its maximum length is 260 bytes.
*/
if (260 < ntohs(param.p->length))
return sctp_process_inv_paramlength(asoc, param.p,
chunk, err_chunk);
if (260 < ntohs(param.p->length)) {
sctp_process_inv_paramlength(asoc, param.p,
chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
}
break;

case SCTP_PARAM_HMAC_ALGO:
Expand All @@ -2020,8 +2022,7 @@ static int sctp_verify_param(const struct sctp_association *asoc,
default:
SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
ntohs(param.p->type), cid);
return sctp_process_unk_param(asoc, param, chunk, err_chunk);

retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
break;
}
return retval;
Expand All @@ -2036,15 +2037,15 @@ int sctp_verify_init(const struct sctp_association *asoc,
{
union sctp_params param;
int has_cookie = 0;
int result;

/* Verify stream values are non-zero. */
if ((0 == peer_init->init_hdr.num_outbound_streams) ||
(0 == peer_init->init_hdr.num_inbound_streams) ||
(0 == peer_init->init_hdr.init_tag) ||
(SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {

sctp_process_inv_mandatory(asoc, chunk, errp);
return 0;
return sctp_process_inv_mandatory(asoc, chunk, errp);
}

/* Check for missing mandatory parameters. */
Expand All @@ -2062,29 +2063,29 @@ int sctp_verify_init(const struct sctp_association *asoc,
* VIOLATION error. We build the ERROR chunk here and let the normal
* error handling code build and send the packet.
*/
if (param.v != (void*)chunk->chunk_end) {
sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
return 0;
}
if (param.v != (void*)chunk->chunk_end)
return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);

/* The only missing mandatory param possible today is
* the state cookie for an INIT-ACK chunk.
*/
if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) {
sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
chunk, errp);
return 0;
}

/* Find unrecognized parameters. */
if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
chunk, errp);

/* Verify all the variable length parameters */
sctp_walk_params(param, peer_init, init_hdr.params) {

if (!sctp_verify_param(asoc, param, cid, chunk, errp)) {
if (SCTP_PARAM_HOST_NAME_ADDRESS == param.p->type)
result = sctp_verify_param(asoc, param, cid, chunk, errp);
switch (result) {
case SCTP_IERROR_ABORT:
case SCTP_IERROR_NOMEM:
return 0;
else
case SCTP_IERROR_ERROR:
return 1;
case SCTP_IERROR_NO_ERROR:
default:
break;
}

} /* for (loop through all parameters) */
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