From b6f56073595800e1bd0b8deafe8259a9da73e07a Mon Sep 17 00:00:00 2001 From: Kevin Harwell Date: Fri, 13 Dec 2019 13:46:17 -0600 Subject: [PATCH] res_fax: wrap v21 detected Asterisk initiated negotiation with config option A previous patch: Gerrit Change-Id: I73bb24799bfe1a48adae9c034a2edbae54cc2a39 made it so a T.38 Gateway tries to negotiate with both sides by sending T.38 negotiation request to both endpoints supported T.38 versus the previous behavior of forwarding negotiation to the "other" channel once a preamble was detected. This had the unfortunate side effect of breaking some setups. Specifically ones that set the max datagram option on an endpoint configuration (configured max datagram was not propagated since Asterisk now initiates negotiations). This patch adds a configuration option, "negotiate_both", that when enabled makes it so Asterisk initiates the negotiation requests to both endpoints vs. the previous behavior of waiting, and forwarding the request. The default is disabled keeping with the old behavior. ASTERISK-28660 Change-Id: I5deb875f3485e20bc75119ec743090655d864a1a --- doc/CHANGES-staging/res_fax_negotiate_both | 7 ++++++ include/asterisk/res_fax.h | 3 +++ res/res_fax.c | 26 +++++++++++++++++++++- 3 files changed, 35 insertions(+), 1 deletion(-) create mode 100644 doc/CHANGES-staging/res_fax_negotiate_both diff --git a/doc/CHANGES-staging/res_fax_negotiate_both b/doc/CHANGES-staging/res_fax_negotiate_both new file mode 100644 index 0000000000..73be756028 --- /dev/null +++ b/doc/CHANGES-staging/res_fax_negotiate_both @@ -0,0 +1,7 @@ +Subject: res_fax + +Added configuration option "negotiate_both". This option is only used +when a gateway is enabled, and a v21 preamble is detected. If this option +is enabled, once a preamble is detected Asterisk will initiate negotiation +requests to both T.38 enabled endpoint versus waiting, and forwarding a +request from an initiating endpoint. Defaults to disabled. diff --git a/include/asterisk/res_fax.h b/include/asterisk/res_fax.h index c1dd37847c..dc455bbfd4 100644 --- a/include/asterisk/res_fax.h +++ b/include/asterisk/res_fax.h @@ -189,6 +189,9 @@ struct ast_fax_session_details { int faxdetect_flags; /*! Non-zero if T.38 is negotiated */ int is_t38_negotiated; + /*! Upon v21 detection the gateway sends negotiation requests to both + T.38 endpoints, and do not wait on the "other" side to initiate */ + int negotiate_both; }; struct ast_fax_tech; diff --git a/res/res_fax.c b/res/res_fax.c index 7d9cb4e8ca..ebb2b46266 100644 --- a/res/res_fax.c +++ b/res/res_fax.c @@ -226,6 +226,9 @@ R/W The timeout used for T.38 negotiation. + + R/W Upon v21 detection allow gateway to send negotiation requests to both T.38 endpoints, and do not wait on the "other" side to initiate (yes|no) + @@ -722,6 +725,7 @@ static struct ast_fax_session_details *session_details_new(void) d->gateway_id = -1; d->faxdetect_id = -1; d->gateway_timeout = 0; + d->negotiate_both = 0; return d; } @@ -3023,6 +3027,22 @@ static struct ast_frame *fax_gateway_detect_v21(struct fax_gateway *gateway, str enum ast_t38_state state_other; enum ast_t38_state state_active; struct ast_frame *fp; + struct ast_fax_session_details *details; + int negotiate_both = 0; + + /* + * The default behavior is to wait for the active endpoint to initiate negotiation. + * Find out if this has been overridden. If so, instead of waiting have Asterisk + * initiate the negotiation requests out to both endpoints. + */ + details = find_or_create_details(active); + if (details) { + negotiate_both = details->negotiate_both; + ao2_ref(details, -1); + } else { + ast_log(LOG_WARNING, "Detect v21 - no session details for channel '%s'\n", + ast_channel_name(chan)); + } destroy_v21_sessions(gateway); @@ -3039,7 +3059,7 @@ static struct ast_frame *fax_gateway_detect_v21(struct fax_gateway *gateway, str } /* May be called endpoint is improperly configured to rely on the calling endpoint * to initiate T.38 re-INVITEs, send T.38 negotiation request to called endpoint */ - if (state_active == T38_STATE_UNKNOWN) { + if (negotiate_both && state_active == T38_STATE_UNKNOWN) { ast_debug(1, "sending T.38 negotiation request to %s\n", ast_channel_name(active)); if (active == chan) { ast_channel_unlock(chan); @@ -4557,6 +4577,8 @@ static int acf_faxopt_read(struct ast_channel *chan, const char *cmd, char *data ast_fax_modem_to_str(details->modems, buf, len); } else if (!strcasecmp(data, "t38timeout")) { snprintf(buf, len, "%u", details->t38timeout); + } else if (!strcasecmp(data, "negotiate_both")) { + ast_copy_string(buf, details->negotiate_both != -1 ? "yes" : "no", len); } else { ast_log(LOG_WARNING, "channel '%s' can't read FAXOPT(%s) because it is unhandled!\n", ast_channel_name(chan), data); res = -1; @@ -4695,6 +4717,8 @@ static int acf_faxopt_write(struct ast_channel *chan, const char *cmd, char *dat } } else if ((!strcasecmp(data, "modem")) || (!strcasecmp(data, "modems"))) { update_modem_bits(&details->modems, value); + } else if (!strcasecmp(data, "negotiate_both")) { + details->negotiate_both = ast_true(ast_skip_blanks(value)); } else { ast_log(LOG_WARNING, "channel '%s' set FAXOPT(%s) to '%s' is unhandled!\n", ast_channel_name(chan), data, value); res = -1;