[sr-dev] git:master: modules_k/presence: Improved handling of retransmitted SUBSCRIBE requests
Peter Dunkley
peter.dunkley at crocodile-rcs.com
Mon Jan 30 18:19:55 CET 2012
Hello,
I believe that this bug also affects the 3.2 branch, but the change is
quite big and with the next release of 3.2 due tomorrow I thought it
best to hold off "cherry-pick"ing it until after the release. That is,
unless anyone else thinks it should go in there?
Regards,
Peter
On Mon, 2012-01-30 at 18:16 +0100, Peter Dunkley wrote:
> Module: sip-router
> Branch: master
> Commit: e6a50c5c0957a5ad3e08e57ede5be775a41ac24f
> URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=e6a50c5c0957a5ad3e08e57ede5be775a41ac24f
>
> Author: pd <peter.dunkley at crocodile-rcs.com>
> Committer: pd <peter.dunkley at crocodile-rcs.com>
> Date: Mon Jan 30 17:06:42 2012 +0000
>
> modules_k/presence: Improved handling of retransmitted SUBSCRIBE requests
>
> - handle_subscribe() doesn't handle retransmitted SUBSCRIBEs properly. This was
> noticed with back-end SUBSCRIBEs from RLS under heavy load (also tried TCP
> here but under-load this caused a different set of problems with buffer
> sizes and buffers taking too long to process).
> - Although this was originally observed with RLS back-end SUBSCRIBEs it
> appears to be a general issue when UDP is used.
> - There were two main problems:
> 1) On an un-SUBSCRIBE the record in the hash-table or DB will be removed. If
> the un-SUBSCRIBE is retransmitted there is no record to be found and
> handle_subscribe() fails.
> 2) After fixing 1, and on re-SUBSCRIBE, remote CSeq's with lower than
> expected values cause failures. This can also happen when there are
> retransmissions.
> - The fix was to catch both these cases and treat them as a special class of
> error. In these two cases and when the protocol is UDP, a correct-looking
> 2XX response is sent, but no further processing (database updates, sending
> NOTIFY, and so on) is performed on the SUBSCRIBE request.
> - Also modified the query in get_database_info() to just use Call-ID, To-tag,
> and From-tag for dialog matching (so it duplicates the query from
> get_stored_info()) as the query that was there looked a little aggressive.
>
> ---
>
> modules_k/presence/subscribe.c | 247 +++++++++++++++++++++------------------
> 1 files changed, 133 insertions(+), 114 deletions(-)
>
> diff --git a/modules_k/presence/subscribe.c b/modules_k/presence/subscribe.c
> index d11287c..8add119 100644
> --- a/modules_k/presence/subscribe.c
> +++ b/modules_k/presence/subscribe.c
> @@ -762,7 +762,10 @@ int handle_subscribe(struct sip_msg* msg, char* str1, char* str2)
> {
> if(get_stored_info(msg, &subs, &reply_code, &reply_str )< 0)
> {
> - LM_ERR("getting stored info\n");
> + if (msg->rcv.proto == PROTO_UDP)
> + LM_INFO("problem getting stored info - possible retransmission\n");
> + else
> + LM_ERR("getting stored info\n");
> goto error;
> }
> reason= subs.reason;
> @@ -885,9 +888,26 @@ error:
>
> if(sent_reply== 0)
> {
> - if(send_error_reply(msg, reply_code, reply_str)< 0)
> + if (reply_code == 200)
> {
> - LM_ERR("failed to send reply on error case\n");
> + if(subs.event->type & PUBL_TYPE)
> + {
> + if(send_2XX_reply(msg, 202, subs.expires,
> + &subs.local_contact) <0)
> + LM_ERR("failed to send reply on error case\n");
> + }
> + else
> + {
> + /* For presence.winfo */
> + if(send_2XX_reply(msg, 200, subs.expires,
> + &subs.local_contact) <0)
> + LM_ERR("failed to send reply on error case\n");
> + }
> + }
> + else
> + {
> + if(send_error_reply(msg, reply_code, reply_str)< 0)
> + LM_ERR("failed to send reply on error case\n");
> }
> }
>
> @@ -1082,21 +1102,21 @@ int extract_sdialog_info(subs_t* subs,struct sip_msg* msg, int mexp,
> subs->contact.s, subs->contact.len);
>
> if (EVENT_DIALOG_SLA(subs->event->evp))
> - {
> - /* user_contact at from_domain */
> - if(parse_uri(subs->contact.s, subs->contact.len, &uri)< 0)
> - {
> - LM_ERR("failed to parse contact uri\n");
> - goto error;
> - }
> - if(uandd_to_uri(uri.user, subs->from_domain, &subs->pres_uri)< 0)
> - {
> - LM_ERR("failed to construct uri\n");
> - goto error;
> - }
> - LM_DBG("&&&&&&&&&&&&&&& dialog pres_uri= %.*s\n",subs->pres_uri.len, subs->pres_uri.s);
> - }
> -
> + {
> + /* user_contact at from_domain */
> + if(parse_uri(subs->contact.s, subs->contact.len, &uri)< 0)
> + {
> + LM_ERR("failed to parse contact uri\n");
> + goto error;
> + }
> + if(uandd_to_uri(uri.user, subs->from_domain, &subs->pres_uri)< 0)
> + {
> + LM_ERR("failed to construct uri\n");
> + goto error;
> + }
> + LM_DBG("&&&&&&&&&&&&&&& dialog pres_uri= %.*s\n",
> + subs->pres_uri.len, subs->pres_uri.s);
> + }
>
> /*process record route and add it to a string*/
> if(*to_tag_gen && msg->record_route!=NULL)
> @@ -1152,18 +1172,17 @@ int get_stored_info(struct sip_msg* msg, subs_t* subs, int* reply_code,
> unsigned int hash_code;
>
> /* first try to_user== pres_user and to_domain== pres_domain */
> -
> - if(subs->pres_uri.s == NULL)
> - {
> - uandd_to_uri(subs->to_user, subs->to_domain, &pres_uri);
> - if(pres_uri.s== NULL)
> - {
> - LM_ERR("creating uri from user and domain\n");
> - return -1;
> - }
> - }
> - else
> - pres_uri = subs->pres_uri;
> + if(subs->pres_uri.s == NULL)
> + {
> + uandd_to_uri(subs->to_user, subs->to_domain, &pres_uri);
> + if(pres_uri.s== NULL)
> + {
> + LM_ERR("creating uri from user and domain\n");
> + return -1;
> + }
> + }
> + else
> + pres_uri = subs->pres_uri;
>
> hash_code= core_hash(&pres_uri, &subs->event->name, shtable_size);
> lock_get(&subs_htable[hash_code].lock);
> @@ -1176,14 +1195,13 @@ int get_stored_info(struct sip_msg* msg, subs_t* subs, int* reply_code,
> }
> lock_release(&subs_htable[hash_code].lock);
>
> - if(subs->pres_uri.s)
> - goto not_found;
> + if(subs->pres_uri.s)
> + goto not_found;
>
> - pkg_free(pres_uri.s);
> + pkg_free(pres_uri.s);
> pres_uri.s= NULL;
> -
>
> - LM_DBG("record not found using R-URI search iteratively\n");
> + LM_DBG("record not found using R-URI search iteratively\n");
> /* take one row at a time */
> for(i= 0; i< shtable_size; i++)
> {
> @@ -1207,26 +1225,35 @@ int get_stored_info(struct sip_msg* msg, subs_t* subs, int* reply_code,
> lock_release(&subs_htable[i].lock);
> }
>
> +not_found:
> if(dbmode != DB_MEMORY_ONLY)
> {
> - return get_database_info(msg, subs, reply_code, reply_str);
> + return get_database_info(msg, subs, reply_code, reply_str);
> }
>
> -not_found:
> -
> - LM_ERR("record not found in hash_table\n");
> - *reply_code= 481;
> - *reply_str= pu_481_rpl;
> + if (msg->rcv.proto == PROTO_UDP && subs->expires == 0)
> + {
> + /* Assume it's a retransmission of an un-SUBSCRIBE */
> + LM_INFO("No matching subscription dialog found in database - possible retransmission of un-SUBSCRIBE?\n");
> + *reply_code= 200;
> + *reply_str= su_200_rpl;
> + }
> + else
> + {
> + /* It's definitely an error */
> + LM_ERR("record not found in hash_table\n");
> + *reply_code= 481;
> + *reply_str= pu_481_rpl;
> + }
>
> return -1;
>
> found_rec:
> -
> LM_DBG("Record found in hash_table\n");
> -
> +
> if(!EVENT_DIALOG_SLA(s->event->evp))
> subs->pres_uri= pres_uri;
> -
> +
> subs->version = s->version;
> subs->status= s->status;
> if(s->reason.s && s->reason.len)
> @@ -1257,14 +1284,25 @@ found_rec:
>
> if(subs->remote_cseq<= s->remote_cseq)
> {
> - LM_ERR("wrong sequence number;received: %d - stored: %d\n",
> - subs->remote_cseq, s->remote_cseq);
> -
> - *reply_code= 400;
> - *reply_str= pu_400_rpl;
>
> lock_release(&subs_htable[i].lock);
> - goto error;
> + if (msg->rcv.proto == PROTO_UDP)
> + {
> + /* Assume it's a retransmission of a SUBSCRIBE */
> + LM_INFO("Possible retransmission of SUBSCRIBE?\n");
> + *reply_code= 200;
> + *reply_str= su_200_rpl;
> + return -1;
> + }
> + else
> + {
> + /* It's definitely an error */
> + LM_ERR("wrong sequence number received: %d - stored: %d\n",
> + subs->remote_cseq, s->remote_cseq);
> + *reply_code= 400;
> + *reply_str= pu_400_rpl;
> + goto error;
> + }
> }
> lock_release(&subs_htable[i].lock);
>
> @@ -1282,64 +1320,20 @@ error:
>
> int get_database_info(struct sip_msg* msg, subs_t* subs, int* reply_code, str* reply_str)
> {
> - db_key_t query_cols[10];
> - db_val_t query_vals[10];
> - db_key_t result_cols[9];
> + db_key_t query_cols[3];
> + db_val_t query_vals[3];
> + db_key_t result_cols[7];
> db1_res_t *result= NULL;
> db_row_t *row ;
> db_val_t *row_vals ;
> int n_query_cols = 0;
> int n_result_cols = 0;
> int remote_cseq_col= 0, local_cseq_col= 0, status_col, reason_col;
> - int record_route_col, version_col;
> - int pres_uri_col;
> + int record_route_col, version_col, pres_uri_col;
> unsigned int remote_cseq;
> str pres_uri, record_route;
> str reason;
>
> - query_cols[n_query_cols] = &str_to_user_col;
> - query_vals[n_query_cols].type = DB1_STR;
> - query_vals[n_query_cols].nul = 0;
> - query_vals[n_query_cols].val.str_val = subs->to_user;
> - n_query_cols++;
> -
> - query_cols[n_query_cols] = &str_to_domain_col;
> - query_vals[n_query_cols].type = DB1_STR;
> - query_vals[n_query_cols].nul = 0;
> - query_vals[n_query_cols].val.str_val = subs->to_domain;
> - n_query_cols++;
> -
> - query_cols[n_query_cols] = &str_watcher_username_col;
> - query_vals[n_query_cols].type = DB1_STR;
> - query_vals[n_query_cols].nul = 0;
> - query_vals[n_query_cols].val.str_val = subs->from_user;
> - n_query_cols++;
> -
> - query_cols[n_query_cols] = &str_watcher_domain_col;
> - query_vals[n_query_cols].type = DB1_STR;
> - query_vals[n_query_cols].nul = 0;
> - query_vals[n_query_cols].val.str_val = subs->from_domain;
> - n_query_cols++;
> -
> - query_cols[n_query_cols] = &str_event_col;
> - query_vals[n_query_cols].type = DB1_STR;
> - query_vals[n_query_cols].nul = 0;
> - query_vals[n_query_cols].val.str_val = subs->event->name;
> - n_query_cols++;
> -
> - query_cols[n_query_cols] = &str_event_id_col;
> - query_vals[n_query_cols].type = DB1_STR;
> - query_vals[n_query_cols].nul = 0;
> - if( subs->event_id.s != NULL)
> - {
> - query_vals[n_query_cols].val.str_val.s = subs->event_id.s;
> - query_vals[n_query_cols].val.str_val.len = subs->event_id.len;
> - } else {
> - query_vals[n_query_cols].val.str_val.s = "";
> - query_vals[n_query_cols].val.str_val.len = 0;
> - }
> - n_query_cols++;
> -
> query_cols[n_query_cols] = &str_callid_col;
> query_vals[n_query_cols].type = DB1_STR;
> query_vals[n_query_cols].nul = 0;
> @@ -1385,29 +1379,29 @@ int get_database_info(struct sip_msg* msg, subs_t* subs, int* reply_code, str* r
>
> if(result && result->n <=0)
> {
> - LM_ERR("No matching subscription dialog found in database\n");
> -
> pa_dbf.free_result(pa_db, result);
> - *reply_code= 481;
> - *reply_str= pu_481_rpl;
> +
> + if (msg->rcv.proto == PROTO_UDP && subs->expires == 0)
> + {
> + /* Assume it's a retransmission of an un-SUBSCRIBE */
> + LM_INFO("No matching subscription dialog found in database - possible retransmission of un-SUBSCRIBE?\n");
> + *reply_code= 200;
> + *reply_str= su_200_rpl;
> + }
> + else
> + {
> + /* It's definitely an error */
> + LM_ERR("No matching subscription dialog found in database\n");
> + *reply_code= 481;
> + *reply_str= pu_481_rpl;
> + }
>
> return -1;
> }
>
> row = &result->rows[0];
> row_vals = ROW_VALUES(row);
> - remote_cseq= row_vals[remote_cseq_col].val.int_val;
> -
> - if(subs->remote_cseq<= remote_cseq)
> - {
> - LM_ERR("wrong sequence number received: %d - stored: %d\n",
> - subs->remote_cseq, remote_cseq);
> - *reply_code= 400;
> - *reply_str= pu_400_rpl;
> - pa_dbf.free_result(pa_db, result);
> - return -1;
> - }
> -
> +
> subs->status= row_vals[status_col].val.int_val;
> reason.s= (char*)row_vals[reason_col].val.string_val;
> if(reason.s)
> @@ -1453,6 +1447,31 @@ int get_database_info(struct sip_msg* msg, subs_t* subs, int* reply_code, str* r
> subs->record_route.len= record_route.len;
> }
>
> + remote_cseq= row_vals[remote_cseq_col].val.int_val;
> + if(subs->remote_cseq<= remote_cseq)
> + {
> + pa_dbf.free_result(pa_db, result);
> +
> + if (msg->rcv.proto == PROTO_UDP)
> + {
> + /* Assume it's a retransmission of a SUBSCRIBE */
> + LM_INFO("Possible retransmission of SUBSCRIBE?\n");
> + *reply_code= 200;
> + *reply_str= su_200_rpl;
> + }
> + else
> + {
> + /* It's definitely an error */
> + LM_ERR("wrong sequence number received: %d - stored: %d\n",
> + subs->remote_cseq, remote_cseq);
> + *reply_code= 400;
> + *reply_str= pu_400_rpl;
> + }
> +
> + return -1;
> + }
> +
> +
> pa_dbf.free_result(pa_db, result);
> result= NULL;
>
>
>
> _______________________________________________
> sr-dev mailing list
> sr-dev at lists.sip-router.org
> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
--
Peter Dunkley
Technical Director
Crocodile RCS Ltd
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