const sctp_subtype_t type,
void *arg,
sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
const struct sctp_association *asoc,
struct sctp_transport *transport);
+static sctp_disposition_t sctp_sf_abort_violation(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ void *arg,
+ sctp_cmd_seq_t *commands,
+ const __u8 *payload,
+ const size_t paylen);
+
static sctp_disposition_t sctp_sf_violation_chunklen(
const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
void *arg,
sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_violation_paramlen(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+static sctp_disposition_t sctp_sf_violation_ctsn(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+static sctp_disposition_t sctp_sf_violation_chunk(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ struct sctp_chunk *chunk);
+
/* Small helper function that checks if the chunk length
* is of the appropriate length. The 'required_length' argument
* is set to be the size of a specific chunk we are testing.
struct sctp_chunk *chunk = arg;
struct sctp_ulpevent *ev;
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
/* RFC 2960 6.10 Bundling
*
* An endpoint MUST NOT bundle INIT, INIT ACK or
* SHUTDOWN COMPLETE with any other chunks.
*/
if (!chunk->singleton)
- return SCTP_DISPOSITION_VIOLATION;
+ return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
- if (!sctp_vtag_verify_either(chunk, asoc))
- return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
/* RFC 2960 10.2 SCTP-to-ULP
*
* notification is passed to the upper layer.
*/
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
- 0, 0, 0, GFP_ATOMIC);
+ 0, 0, 0, NULL, GFP_ATOMIC);
if (ev)
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
SCTP_ULPEVENT(ev));
struct sctp_chunk *err_chunk;
struct sctp_packet *packet;
sctp_unrecognized_param_t *unk_param;
- struct sock *sk;
int len;
/* 6.10 Bundling
if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
- sk = ep->base.sk;
- /* If the endpoint is not listening or if the number of associations
- * on the TCP-style socket exceed the max backlog, respond with an
- * ABORT.
- */
- if (!sctp_sstate(sk, LISTENING) ||
- (sctp_style(sk, TCP) &&
- sk_acceptq_is_full(sk)))
- return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
-
/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
* Tag.
*/
if (!sctp_vtag_verify(chunk, asoc))
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
- /* Make sure that the INIT-ACK chunk has a valid length */
- if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
- return sctp_sf_violation_chunklen(ep, asoc, type, arg,
- commands);
/* 6.10 Bundling
* An endpoint MUST NOT bundle INIT, INIT ACK or
* SHUTDOWN COMPLETE with any other chunks.
*/
if (!chunk->singleton)
- return SCTP_DISPOSITION_VIOLATION;
+ return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
+ /* Make sure that the INIT-ACK chunk has a valid length */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
/* Grab the INIT header. */
chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
(sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
&err_chunk)) {
- SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
-
/* This chunk contains fatal error. It is to be discarded.
* Send an ABORT, with causes if there is any.
*/
sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
error = SCTP_ERROR_INV_PARAM;
}
+
+ /* SCTP-AUTH, Section 6.3:
+ * It should be noted that if the receiver wants to tear
+ * down an association in an authenticated way only, the
+ * handling of malformed packets should not result in
+ * tearing down the association.
+ *
+ * This means that if we only want to abort associations
+ * in an authenticated way (i.e AUTH+ABORT), then we
+ * can't destory this association just becuase the packet
+ * was malformed.
+ */
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
asoc, chunk->transport);
}
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
+ /* SCTP-AUTH: genereate the assocition shared keys so that
+ * we can potentially signe the COOKIE-ECHO.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
+
/* 5.1 C) "A" shall then send the State Cookie received in the
* INIT ACK chunk in a COOKIE ECHO chunk, ...
*/
struct sctp_ulpevent *ev, *ai_ev = NULL;
int error = 0;
struct sctp_chunk *err_chk_p;
+ struct sock *sk;
/* If the packet is an OOTB packet which is temporarily on the
* control endpoint, respond with an ABORT.
*/
if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
- return sctp_sf_ootb(ep, asoc, type, arg, commands);
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
/* Make sure that the COOKIE_ECHO chunk has a valid length.
* In this case, we check that we have enough for at least a
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ /* If the endpoint is not listening or if the number of associations
+ * on the TCP-style socket exceed the max backlog, respond with an
+ * ABORT.
+ */
+ sk = ep->base.sk;
+ if (!sctp_sstate(sk, LISTENING) ||
+ (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
+
/* "Decode" the chunk. We have no optional parameters so we
* are in good shape.
*/
case -SCTP_IERROR_BAD_SIG:
default:
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
- };
+ }
}
peer_init, GFP_ATOMIC))
goto nomem_init;
+ /* SCTP-AUTH: Now that we've populate required fields in
+ * sctp_process_init, set up the assocaition shared keys as
+ * necessary so that we can potentially authenticate the ACK
+ */
+ error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
+ if (error)
+ goto nomem_init;
+
+ /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
+ * is supposed to be authenticated and we have to do delayed
+ * authentication. We've just recreated the association using
+ * the information in the cookie and now it's much easier to
+ * do the authentication.
+ */
+ if (chunk->auth_chunk) {
+ struct sctp_chunk auth;
+ sctp_ierror_t ret;
+
+ /* set-up our fake chunk so that we can process it */
+ auth.skb = chunk->auth_chunk;
+ auth.asoc = chunk->asoc;
+ auth.sctp_hdr = chunk->sctp_hdr;
+ auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
+ sizeof(sctp_chunkhdr_t));
+ skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
+ auth.transport = chunk->transport;
+
+ ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
+
+ /* We can now safely free the auth_chunk clone */
+ kfree_skb(chunk->auth_chunk);
+
+ if (ret != SCTP_IERROR_NO_ERROR) {
+ sctp_association_free(new_asoc);
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ }
+ }
+
repl = sctp_make_cookie_ack(new_asoc, chunk);
if (!repl)
goto nomem_init;
ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
new_asoc->c.sinit_num_ostreams,
new_asoc->c.sinit_max_instreams,
- GFP_ATOMIC);
+ NULL, GFP_ATOMIC);
if (!ev)
goto nomem_ev;
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
0, asoc->c.sinit_num_ostreams,
asoc->c.sinit_max_instreams,
- GFP_ATOMIC);
+ NULL, GFP_ATOMIC);
if (!ev)
goto nomem;
{
struct sctp_transport *transport = (struct sctp_transport *) arg;
- if (asoc->overall_error_count >= asoc->max_retrans) {
+ if (asoc->overall_error_count > asoc->max_retrans) {
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
SCTP_ERROR(ETIMEDOUT));
/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
/* This should never happen, but lets log it if so. */
if (unlikely(!link)) {
if (from_addr.sa.sa_family == AF_INET6) {
- printk(KERN_WARNING
- "%s association %p could not find address "
- NIP6_FMT "\n",
- __FUNCTION__,
- asoc,
- NIP6(from_addr.v6.sin6_addr));
+ if (net_ratelimit())
+ printk(KERN_WARNING
+ "%s association %p could not find address "
+ NIP6_FMT "\n",
+ __FUNCTION__,
+ asoc,
+ NIP6(from_addr.v6.sin6_addr));
} else {
- printk(KERN_WARNING
- "%s association %p could not find address "
- NIPQUAD_FMT "\n",
- __FUNCTION__,
- asoc,
- NIPQUAD(from_addr.v4.sin_addr.s_addr));
+ if (net_ratelimit())
+ printk(KERN_WARNING
+ "%s association %p could not find address "
+ NIPQUAD_FMT "\n",
+ __FUNCTION__,
+ asoc,
+ NIPQUAD(from_addr.v4.sin_addr.s_addr));
}
return SCTP_DISPOSITION_DISCARD;
}
/* Check if the timestamp looks valid. */
if (time_after(hbinfo->sent_at, jiffies) ||
time_after(jiffies, hbinfo->sent_at + max_interval)) {
- SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
+ SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
"received for transport: %p\n",
__FUNCTION__, link);
return SCTP_DISPOSITION_DISCARD;
new_asoc->c.my_ttag = asoc->c.my_vtag;
new_asoc->c.peer_ttag = asoc->c.peer_vtag;
break;
- };
+ }
/* Other parameters for the endpoint SHOULD be copied from the
* existing parameters of the association (e.g. number of
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
new_asoc->c.sinit_num_ostreams,
new_asoc->c.sinit_max_instreams,
- GFP_ATOMIC);
+ NULL, GFP_ATOMIC);
if (!ev)
goto nomem_ev;
struct sctp_association *new_asoc)
{
sctp_init_chunk_t *peer_init;
- struct sctp_ulpevent *ev;
struct sctp_chunk *repl;
/* new_asoc is a brand-new association, so these are not yet
* D) IMPLEMENTATION NOTE: An implementation may choose to
* send the Communication Up notification to the SCTP user
* upon reception of a valid COOKIE ECHO chunk.
+ *
+ * Sadly, this needs to be implemented as a side-effect, because
+ * we are not guaranteed to have set the association id of the real
+ * association and so these notifications need to be delayed until
+ * the association id is allocated.
*/
- ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
- new_asoc->c.sinit_num_ostreams,
- new_asoc->c.sinit_max_instreams,
- GFP_ATOMIC);
- if (!ev)
- goto nomem_ev;
- sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
/* Sockets API Draft Section 5.3.1.6
* When a peer sends a Adaptation Layer Indication parameter , SCTP
* delivers this notification to inform the application that of the
* peers requested adaptation layer.
+ *
+ * This also needs to be done as a side effect for the same reason as
+ * above.
*/
- if (asoc->peer.adaptation_ind) {
- ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
- if (!ev)
- goto nomem_ev;
-
- sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
- SCTP_ULPEVENT(ev));
- }
+ if (asoc->peer.adaptation_ind)
+ sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
return SCTP_DISPOSITION_CONSUME;
-nomem_ev:
- sctp_chunk_free(repl);
nomem:
return SCTP_DISPOSITION_NOMEM;
}
SCTP_COMM_UP, 0,
asoc->c.sinit_num_ostreams,
asoc->c.sinit_max_instreams,
- GFP_ATOMIC);
+ NULL, GFP_ATOMIC);
if (!ev)
goto nomem;
case -SCTP_IERROR_BAD_SIG:
default:
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
- };
+ }
}
/* Compare the tie_tag in cookie with the verification tag of
default: /* Discard packet for all others. */
retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
break;
- };
+ }
/* Delete the tempory new association. */
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
/* If we've sent any data bundled with COOKIE-ECHO we will need to
* resend
*/
- sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
+ sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
SCTP_TRANSPORT(asoc->peer.primary_path));
/* Cast away the const modifier, as we want to just
struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
struct sctp_chunk *reply;
+ /* Make sure that the chunk has a valid length */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
/* Since we are not going to really process this INIT, there
* is no point in verifying chunk boundries. Just generate
* the SHUTDOWN ACK.
return SCTP_DISPOSITION_DISCARD;
}
+ /* If Cumulative TSN Ack beyond the max tsn currently
+ * send, terminating the association and respond to the
+ * sender with an ABORT.
+ */
+ if (!TSN_lt(ctsn, asoc->next_tsn))
+ return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
+
/* Return this SACK for further processing. */
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
*
* The return value is the disposition of the chunk.
*/
-sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
+static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
const sctp_subtype_t type,
void *arg,
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+ sctp_sf_pdiscard(ep, asoc, type, arg, commands);
return SCTP_DISPOSITION_CONSUME;
}
* notification is passed to the upper layer.
*/
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
- 0, 0, 0, GFP_ATOMIC);
+ 0, 0, 0, NULL, GFP_ATOMIC);
if (!ev)
goto nomem;
ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
do {
- /* Break out if chunk length is less then minimal. */
+ /* Report violation if the chunk is less then minimal */
if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
- break;
-
- ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
- if (ch_end > skb->tail)
- break;
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+ /* Now that we know we at least have a chunk header,
+ * do things that are type appropriate.
+ */
if (SCTP_CID_SHUTDOWN_ACK == ch->type)
ootb_shut_ack = 1;
if (SCTP_CID_ABORT == ch->type)
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ /* Report violation if chunk len overflows */
+ ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+ if (ch_end > skb_tail_pointer(skb))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
ch = (sctp_chunkhdr_t *) ch_end;
- } while (ch_end < skb->tail);
+ } while (ch_end < skb_tail_pointer(skb));
if (ootb_shut_ack)
- sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
+ return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
else
- sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
-
- return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
}
/*
if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
- return SCTP_DISPOSITION_CONSUME;
+ /* We need to discard the rest of the packet to prevent
+ * potential bomming attacks from additional bundled chunks.
+ * This is documented in SCTP Threats ID.
+ */
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
}
return SCTP_DISPOSITION_NOMEM;
void *arg,
sctp_cmd_seq_t *commands)
{
+ struct sctp_chunk *chunk = arg;
+
+ /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
/* Although we do have an association in this case, it corresponds
* to a restarted association. So the packet is treated as an OOTB
* packet and the state function that handles OOTB SHUTDOWN_ACK is
{
struct sctp_chunk *chunk = arg;
struct sctp_chunk *asconf_ack = NULL;
+ struct sctp_paramhdr *err_param = NULL;
sctp_addiphdr_t *hdr;
+ union sctp_addr_param *addr_param;
__u32 serial;
+ int length;
if (!sctp_vtag_verify(chunk, asoc)) {
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
hdr = (sctp_addiphdr_t *)chunk->skb->data;
serial = ntohl(hdr->serial);
+ addr_param = (union sctp_addr_param *)hdr->params;
+ length = ntohs(addr_param->p.length);
+ if (length < sizeof(sctp_paramhdr_t))
+ return sctp_sf_violation_paramlen(ep, asoc, type,
+ (void *)addr_param, commands);
+
+ /* Verify the ASCONF chunk before processing it. */
+ if (!sctp_verify_asconf(asoc,
+ (sctp_paramhdr_t *)((void *)addr_param + length),
+ (void *)chunk->chunk_end,
+ &err_param))
+ return sctp_sf_violation_paramlen(ep, asoc, type,
+ (void *)&err_param, commands);
+
/* ADDIP 4.2 C1) Compare the value of the serial number to the value
* the endpoint stored in a new association variable
* 'Peer-Serial-Number'.
struct sctp_chunk *asconf_ack = arg;
struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
struct sctp_chunk *abort;
+ struct sctp_paramhdr *err_param = NULL;
sctp_addiphdr_t *addip_hdr;
__u32 sent_serial, rcvd_serial;
addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
rcvd_serial = ntohl(addip_hdr->serial);
+ /* Verify the ASCONF-ACK chunk before processing it. */
+ if (!sctp_verify_asconf(asoc,
+ (sctp_paramhdr_t *)addip_hdr->params,
+ (void *)asconf_ack->chunk_end,
+ &err_param))
+ return sctp_sf_violation_paramlen(ep, asoc, type,
+ (void *)&err_param, commands);
+
if (last_asconf) {
addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
sent_serial = ntohl(addip_hdr->serial);
abort = sctp_make_abort(asoc, asconf_ack,
sizeof(sctp_errhdr_t));
if (abort) {
- sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
+ sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(abort));
}
abort = sctp_make_abort(asoc, asconf_ack,
sizeof(sctp_errhdr_t));
if (abort) {
- sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
+ sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(abort));
}
}
/*
+ * SCTP-AUTH Section 6.3 Receving authenticated chukns
+ *
+ * The receiver MUST use the HMAC algorithm indicated in the HMAC
+ * Identifier field. If this algorithm was not specified by the
+ * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
+ * during association setup, the AUTH chunk and all chunks after it MUST
+ * be discarded and an ERROR chunk SHOULD be sent with the error cause
+ * defined in Section 4.1.
+ *
+ * If an endpoint with no shared key receives a Shared Key Identifier
+ * other than 0, it MUST silently discard all authenticated chunks. If
+ * the endpoint has at least one endpoint pair shared key for the peer,
+ * it MUST use the key specified by the Shared Key Identifier if a
+ * key has been configured for that Shared Key Identifier. If no
+ * endpoint pair shared key has been configured for that Shared Key
+ * Identifier, all authenticated chunks MUST be silently discarded.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * The return value is the disposition of the chunk.
+ */
+static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ struct sctp_chunk *chunk)
+{
+ struct sctp_authhdr *auth_hdr;
+ struct sctp_hmac *hmac;
+ unsigned int sig_len;
+ __u16 key_id;
+ __u8 *save_digest;
+ __u8 *digest;
+
+ /* Pull in the auth header, so we can do some more verification */
+ auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
+ chunk->subh.auth_hdr = auth_hdr;
+ skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
+
+ /* Make sure that we suport the HMAC algorithm from the auth
+ * chunk.
+ */
+ if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
+ return SCTP_IERROR_AUTH_BAD_HMAC;
+
+ /* Make sure that the provided shared key identifier has been
+ * configured
+ */
+ key_id = ntohs(auth_hdr->shkey_id);
+ if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
+ return SCTP_IERROR_AUTH_BAD_KEYID;
+
+
+ /* Make sure that the length of the signature matches what
+ * we expect.
+ */
+ sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
+ hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
+ if (sig_len != hmac->hmac_len)
+ return SCTP_IERROR_PROTO_VIOLATION;
+
+ /* Now that we've done validation checks, we can compute and
+ * verify the hmac. The steps involved are:
+ * 1. Save the digest from the chunk.
+ * 2. Zero out the digest in the chunk.
+ * 3. Compute the new digest
+ * 4. Compare saved and new digests.
+ */
+ digest = auth_hdr->hmac;
+ skb_pull(chunk->skb, sig_len);
+
+ save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
+ if (!save_digest)
+ goto nomem;
+
+ memset(digest, 0, sig_len);
+
+ sctp_auth_calculate_hmac(asoc, chunk->skb,
+ (struct sctp_auth_chunk *)chunk->chunk_hdr,
+ GFP_ATOMIC);
+
+ /* Discard the packet if the digests do not match */
+ if (memcmp(save_digest, digest, sig_len)) {
+ kfree(save_digest);
+ return SCTP_IERROR_BAD_SIG;
+ }
+
+ kfree(save_digest);
+ chunk->auth = 1;
+
+ return SCTP_IERROR_NO_ERROR;
+nomem:
+ return SCTP_IERROR_NOMEM;
+}
+
+sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_authhdr *auth_hdr;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *err_chunk;
+ sctp_ierror_t error;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ }
+
+ /* Make sure that the AUTH chunk has valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
+ auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
+ error = sctp_sf_authenticate(ep, asoc, type, chunk);
+ switch (error) {
+ case SCTP_IERROR_AUTH_BAD_HMAC:
+ /* Generate the ERROR chunk and discard the rest
+ * of the packet
+ */
+ err_chunk = sctp_make_op_error(asoc, chunk,
+ SCTP_ERROR_UNSUP_HMAC,
+ &auth_hdr->hmac_id,
+ sizeof(__u16));
+ if (err_chunk) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err_chunk));
+ }
+ /* Fall Through */
+ case SCTP_IERROR_AUTH_BAD_KEYID:
+ case SCTP_IERROR_BAD_SIG:
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ break;
+ case SCTP_IERROR_PROTO_VIOLATION:
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+ break;
+ case SCTP_IERROR_NOMEM:
+ return SCTP_DISPOSITION_NOMEM;
+ default:
+ break;
+ }
+
+ if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
+ struct sctp_ulpevent *ev;
+
+ ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
+ SCTP_AUTH_NEWKEY, GFP_ATOMIC);
+
+ if (!ev)
+ return -ENOMEM;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
* Process an unknown chunk.
*
* Section: 3.2. Also, 2.1 in the implementor's guide.
void *arg,
sctp_cmd_seq_t *commands)
{
+ struct sctp_chunk *chunk = arg;
+
+ /* Make sure that the chunk has a valid length.
+ * Since we don't know the chunk type, we use a general
+ * chunkhdr structure to make a comparison.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
return SCTP_DISPOSITION_DISCARD;
}
void *arg,
sctp_cmd_seq_t *commands)
{
+ struct sctp_chunk *chunk = arg;
+
+ /* Make sure that the chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
return SCTP_DISPOSITION_VIOLATION;
}
+/*
+ * Common function to handle a protocol violation.
+ */
+static sctp_disposition_t sctp_sf_abort_violation(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ void *arg,
+ sctp_cmd_seq_t *commands,
+ const __u8 *payload,
+ const size_t paylen)
+{
+ struct sctp_packet *packet = NULL;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *abort = NULL;
+
+ /* SCTP-AUTH, Section 6.3:
+ * It should be noted that if the receiver wants to tear
+ * down an association in an authenticated way only, the
+ * handling of malformed packets should not result in
+ * tearing down the association.
+ *
+ * This means that if we only want to abort associations
+ * in an authenticated way (i.e AUTH+ABORT), then we
+ * can't destory this association just becuase the packet
+ * was malformed.
+ */
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ goto discard;
+
+ /* Make the abort chunk. */
+ abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
+ if (!abort)
+ goto nomem;
+
+ if (asoc) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+ SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+
+ if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNREFUSED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+ SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
+ }
+ } else {
+ packet = sctp_ootb_pkt_new(asoc, chunk);
+
+ if (!packet)
+ goto nomem_pkt;
+
+ if (sctp_test_T_bit(abort))
+ packet->vtag = ntohl(chunk->sctp_hdr->vtag);
+
+ abort->skb->sk = ep->base.sk;
+
+ sctp_packet_append_chunk(packet, abort);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+
+ SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+ }
+
+discard:
+ sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
+
+ SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
+
+ return SCTP_DISPOSITION_ABORT;
+
+nomem_pkt:
+ sctp_chunk_free(abort);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
/*
* Handle a protocol violation when the chunk length is invalid.
void *arg,
sctp_cmd_seq_t *commands)
{
- struct sctp_chunk *chunk = arg;
- struct sctp_chunk *abort = NULL;
- char err_str[]="The following chunk had invalid length:";
+ char err_str[]="The following chunk had invalid length:";
- /* Make the abort chunk. */
- abort = sctp_make_abort_violation(asoc, chunk, err_str,
- sizeof(err_str));
- if (!abort)
- goto nomem;
+ return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
- sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
- SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+/*
+ * Handle a protocol violation when the parameter length is invalid.
+ * "Invalid" length is identified as smaller then the minimal length a
+ * given parameter can be.
+ */
+static sctp_disposition_t sctp_sf_violation_paramlen(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands) {
+ char err_str[] = "The following parameter had invalid length:";
- if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
- sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
- SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
- sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
- SCTP_ERROR(ECONNREFUSED));
- sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
- SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
- } else {
- sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
- SCTP_ERROR(ECONNABORTED));
- sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
- SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
- SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
- }
+ return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
- sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+/* Handle a protocol violation when the peer trying to advance the
+ * cumulative tsn ack to a point beyond the max tsn currently sent.
+ *
+ * We inform the other end by sending an ABORT with a Protocol Violation
+ * error code.
+ */
+static sctp_disposition_t sctp_sf_violation_ctsn(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
- SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
+ return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
- return SCTP_DISPOSITION_ABORT;
+/* Handle protocol violation of an invalid chunk bundling. For example,
+ * when we have an association and we recieve bundled INIT-ACK, or
+ * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
+ * statement from the specs. Additinally, there might be an attacker
+ * on the path and we may not want to continue this communication.
+ */
+static sctp_disposition_t sctp_sf_violation_chunk(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ char err_str[]="The following chunk violates protocol:";
-nomem:
- return SCTP_DISPOSITION_NOMEM;
-}
+ if (!asoc)
+ return sctp_sf_violation(ep, asoc, type, arg, commands);
+ return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
/***************************************************************************
* These are the state functions for handling primitive (Section 10) events.
***************************************************************************/
default:
BUG();
break;
- };
+ }
if (!reply)
goto nomem;
* association exists, otherwise, use the peer's vtag.
*/
if (asoc) {
- vtag = asoc->peer.i.init_tag;
+ /* Special case the INIT-ACK as there is no peer's vtag
+ * yet.
+ */
+ switch(chunk->chunk_hdr->type) {
+ case SCTP_CID_INIT_ACK:
+ {
+ sctp_initack_chunk_t *initack;
+
+ initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
+ vtag = ntohl(initack->init_hdr.init_tag);
+ break;
+ }
+ default:
+ vtag = asoc->peer.i.init_tag;
+ break;
+ }
} else {
/* Special case the INIT and stale COOKIE_ECHO as there is no
* vtag yet.
sctp_verb_t deliver;
int tmp;
__u32 tsn;
- int account_value;
struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
struct sock *sk = asoc->base.sk;
- int rcvbuf_over = 0;
data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
/* ASSERT: Now skb->data is really the user data. */
- /*
- * If we are established, and we have used up our receive buffer
- * memory, think about droping the frame.
- * Note that we have an opportunity to improve performance here.
- * If we accept one chunk from an skbuff, we have to keep all the
- * memory of that skbuff around until the chunk is read into user
- * space. Therefore, once we accept 1 chunk we may as well accept all
- * remaining chunks in the skbuff. The data_accepted flag helps us do
- * that.
- */
- if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
- /*
- * If the receive buffer policy is 1, then each
- * association can allocate up to sk_rcvbuf bytes
- * otherwise, all the associations in aggregate
- * may allocate up to sk_rcvbuf bytes
- */
- if (asoc->ep->rcvbuf_policy)
- account_value = atomic_read(&asoc->rmem_alloc);
- else
- account_value = atomic_read(&sk->sk_rmem_alloc);
- if (account_value > sk->sk_rcvbuf) {
- /*
- * We need to make forward progress, even when we are
- * under memory pressure, so we always allow the
- * next tsn after the ctsn ack point to be accepted.
- * This lets us avoid deadlocks in which we have to
- * drop frames that would otherwise let us drain the
- * receive queue.
- */
- if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
- return SCTP_IERROR_IGNORE_TSN;
-
- /*
- * We're going to accept the frame but we should renege
- * to make space for it. This will send us down that
- * path later in this function.
- */
- rcvbuf_over = 1;
- }
- }
-
/* Process ECN based congestion.
*
* Since the chunk structure is reused for all chunks within
* seems a bit troublesome in that frag_point varies based on
* PMTU. In cases, such as loopback, this might be a rather
* large spill over.
- * NOTE: If we have a full receive buffer here, we only renege if
- * our receiver can still make progress without the tsn being
- * received. We do this because in the event that the associations
- * receive queue is empty we are filling a leading gap, and since
- * reneging moves the gap to the end of the tsn stream, we are likely
- * to stall again very shortly. Avoiding the renege when we fill a
- * leading gap is a good heuristic for avoiding such steady state
- * stalls.
- */
- if (!asoc->rwnd || asoc->rwnd_over ||
- (datalen > asoc->rwnd + asoc->frag_point) ||
- (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
+ */
+ if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
+ (datalen > asoc->rwnd + asoc->frag_point))) {
/* If this is the next TSN, consider reneging to make
* room. Note: Playing nice with a confused sender. A
}
/*
+ * Also try to renege to limit our memory usage in the event that
+ * we are under memory pressure
+ * If we can't renege, don't worry about it, the sk_stream_rmem_schedule
+ * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
+ * memory usage too much
+ */
+ if (*sk->sk_prot_creator->memory_pressure) {
+ if (sctp_tsnmap_has_gap(map) &&
+ (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
+ SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
+ deliver = SCTP_CMD_RENEGE;
+ }
+ }
+
+ /*
* Section 3.3.10.9 No User Data (9)
*
* Cause of error
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff