[SR-Dev] Patch: convert utils module to use sr msg_send

[Andrei Pelinescu-Onciul]

On Mar 18, 2009 at 16:57, Henning Westerholt <henning.westerholt at 1und1.de> wrote:
> Hi,
> 
> attached patch converts the utils module to use the sr msg_send functionality. 
> Please review if the API is used correct.

Look ok.

> 
> In kamailio we use this "while( get_next_su( proxy, to, 0) == 0 );" construct 
> to loop over all destinations (e.g. for failover), how this is handled in sr?

    int err;
    struct dns_srv_handle dns_srv_h;


    dns_srv_handle_init(&dns_srv_h);
    err=dns_sip_resolve2su(&dns_srv_h, &send_info->to, dst, port,
                            &proto, dns_flags);
    if (err!=0){ /* ERROR */ }

    do{
        /* ... get_send_socket a.s.o */
        if (msg_send(send_info, buf, len)<0) continue;
    }while( dns_srv_handle_next(&dns_srv_h, err) && 
            ((err=dns_sip_resolve2su(&dns_srv_h, &send_info->to, dst, port,
                                      &proto, dns_flags)) == 0) );
    dns_srv_handle_put(&dns_srv_h); /* very important, don't forget or the
                                       the corresp. dns cache entry won't ever
                                       be freed */

(lots of stuff omitted, like error checks, blacklist check/add, 
 dns failover on/off checks, #ifdefs for USE_DNS_FAILOVER a.s.o.)

Basically dns_srv_handle_next() selects the next ip and also tells if there are
no more ips availale. It needs a struct dns_srv_handle which was used before in
a call to dns_sip_resolve*() and the return value (err) of the last
dns_sip_resolve*() call. You could use 0 instead of err, if you check
dns_sip_resolve*() return in some other place and stop the loop on error.


For a more complete example, see forward_request() in forward.c.

You might be able to use forward_request() directly and get rid of all the send
and failover code (I haven't checked if it's possible or utils_forward() needs
 something more special). forward_request() will also use the blacklist (if
configured).


Andrei


> diff --git a/modules/utils/utils.c b/modules/utils/utils.c
> index 0042f87..cc5dd3b 100644
> --- a/modules/utils/utils.c
> +++ b/modules/utils/utils.c
> @@ -275,14 +275,10 @@ static int fixup_free_http_query(void** param, int param_no)
>  int utils_forward(struct sip_msg *msg, int id, int proto)
>  {
>  	int ret = -1;
> -	union sockaddr_union* to = NULL;
> -	struct socket_info *send_sock = NULL;
> +	struct dest_info dst;
>  
> -	to = (union sockaddr_union*)pkg_malloc(sizeof(union sockaddr_union));
> -	if (to == NULL) {
> -		PKG_MEM_ERROR;
> -		return -1;
> -	}
> +	init_dest_info(&dst);
> +	dst.proto = proto;
>  
>  	// critical section start:
>  	// avoids dirty reads when updating configuration.
> @@ -291,29 +287,23 @@ int utils_forward(struct sip_msg *msg, int id, int proto)
>  	struct proxy_l *proxy = conf_needs_forward(msg, id);
>  
>  	if (proxy != NULL) {
> -		hostent2su(to, &proxy->host, proxy->addr_idx, (proxy->port)?proxy->port:SIP_PORT);
> -		do {
> -			send_sock=get_send_socket(msg, to, proto);
> -
> -			if (send_sock==0) {
> -				LM_ERR("cannot forward to af %d, "
> -					"proto %d no corresponding listening socket\n", to->s.sa_family, proto);
> -				continue;
> -			}
> -			LM_DBG("Sending:\n%.*s.\n", (int)msg->len,msg->buf);
> -
> -			if (msg_send(send_sock, proto, to, 0, msg->buf,msg->len)<0){
> -				LM_ERR("Error sending message!\n");
> -				continue;
> -			}
> -			ret = 0;
> -        		break;
> -		} while( get_next_su( proxy, to, 0) == 0 );
> +		proxy2su(&dst.to, proxy);
> +
> +		dst.send_sock = get_send_socket(msg, &dst.to, dst.proto);
> +		if (dst.send_sock==0) {
> +			LM_ERR("cannot forward to af %d, proto %d no corresponding"
> +					"listening socket\n", dst.to.s.sa_family, proto);
> +		}
> +		LM_DBG("Sending:\n%.*s.\n", (int)msg->len,msg->buf);
> +
> +		if (msg_send(&dst, msg->buf, msg->len)<0){
> +			LM_ERR("Error sending message!\n");
> +		}
> +		ret = 0;
>  	}
>  
>  	// critical section end
>  	lock_release(conf_lock);
> -	pkg_free(to);
>  
>  	return ret;
>  }

> _______________________________________________
> sr-dev mailing list
> sr-dev at lists.sip-router.org
> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev