diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c index 2d5bee5f368e3e857dc7116d4b7f342694c084a5..e493a049e660f5f5394a849d5932bf24bebde669 100644 --- a/channels/chan_iax2.c +++ b/channels/chan_iax2.c @@ -141,7 +141,7 @@ static struct ast_codec_pref prefs; static const char tdesc[] = "Inter Asterisk eXchange Driver (Ver 2)"; -/*! \brief Maximum transimission unit for the UDP packet in the trunk not to be +/*! \brief Maximum transmission unit for the UDP packet in the trunk not to be fragmented. This is based on 1516 - ethernet - ip - udp - iax minus one g711 frame = 1240 */ #define MAX_TRUNK_MTU 1240 @@ -488,7 +488,7 @@ struct chan_iax2_pvt { /*! Next outgoing timestamp if everything is good */ unsigned int nextpred; /*! True if the last voice we transmitted was not silence/CNG */ - int notsilenttx; + unsigned int notsilenttx:1; /*! Ping time */ unsigned int pingtime; /*! Max time for initial response */ @@ -593,7 +593,7 @@ struct chan_iax2_pvt { enum iax_transfer_state transferring; /*! Transfer identifier */ int transferid; - /*! Who we are IAX transfering to */ + /*! Who we are IAX transferring to */ struct sockaddr_in transfer; /*! What's the new call number for the transfer */ unsigned short transfercallno; @@ -740,7 +740,7 @@ static void jb_error_output(const char *fmt, ...) char buf[1024]; va_start(args, fmt); - vsnprintf(buf, 1024, fmt, args); + vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); ast_log(LOG_ERROR, buf); @@ -752,7 +752,7 @@ static void jb_warning_output(const char *fmt, ...) char buf[1024]; va_start(args, fmt); - vsnprintf(buf, 1024, fmt, args); + vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); ast_log(LOG_WARNING, buf); @@ -764,15 +764,48 @@ static void jb_debug_output(const char *fmt, ...) char buf[1024]; va_start(args, fmt); - vsnprintf(buf, 1024, fmt, args); + vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); ast_verbose(buf); } -/* XXX We probably should use a mutex when working with this XXX */ +/*! + * \brief an array of iax2 pvt structures + * + * The container for active chan_iax2_pvt structures is implemented as an + * array for extremely quick direct access to the correct pvt structure + * based on the local call number. The local call number is used as the + * index into the array where the associated pvt structure is stored. + */ static struct chan_iax2_pvt *iaxs[IAX_MAX_CALLS]; +/*! + * \brief chan_iax2_pvt structure locks + * + * These locks are used when accessing a pvt structure in the iaxs array. + * The index used here is the same as used in the iaxs array. It is the + * local call number for the associated pvt struct. + */ static ast_mutex_t iaxsl[IAX_MAX_CALLS]; +/*! + * \brief The last time a call number was used + * + * It is important to know the last time that a call number was used locally so + * that it is not used again too soon. The reason for this is the same as the + * reason that the TCP protocol state machine requires a "TIME WAIT" state. + * + * For example, say that a call is up. Then, the remote side sends a HANGUP, + * which we respond to with an ACK. However, there is no way to know whether + * the ACK made it there successfully. If it were to get lost, the remote + * side may retransmit the HANGUP. If in the meantime, this call number has + * been reused locally, given the right set of circumstances, this retransmitted + * HANGUP could potentially improperly hang up the new session. So, to avoid + * this potential issue, we must wait a specified timeout period before reusing + * a local call number. + * + * The specified time that we must wait before reusing a local call number is + * defined as MIN_REUSE_TIME, with a default of 60 seconds. + */ static struct timeval lastused[IAX_MAX_CALLS]; static enum ast_bridge_result iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc, int timeoutms); @@ -1580,7 +1613,7 @@ static int __do_deliver(void *data) static int handle_error(void) { - /* XXX Ideally we should figure out why an error occured and then abort those + /* XXX Ideally we should figure out why an error occurred and then abort those rather than continuing to try. Unfortunately, the published interface does not seem to work XXX */ #if 0 @@ -3840,7 +3873,7 @@ static int iax2_send(struct chan_iax2_pvt *pvt, struct ast_frame *f, unsigned in /* Bail here if this is an "interp" frame; we don't want or need to send these placeholders out * (the endpoint should detect the lost packet itself). But, we want to do this here, so that we - * increment the "predicted timestamps" for voice, if we're predecting */ + * increment the "predicted timestamps" for voice, if we're predicting */ if(f->frametype == AST_FRAME_VOICE && f->datalen == 0) return 0;