Network stack locking question

[Bruce M. Simpson]

Ivo Vachkov wrote:
> My lookup code looks like the following:
>
> 	struct sockaddr_in6 *dst = NULL;
> 	struct route_in6 out_rt;
>
>         /* ... */
>
> 	dst = (struct sockaddr_in6 *)&out_rt.ro_dst;
> 	bzero(dst, sizeof(*dst));
> 	dst->sin6_len = sizeof(struct sockaddr_in6);
> 	dst->sin6_family = AF_INET6;
> 	dst->sin6_addr = ip6->ip6_dst;
>
> 	rtalloc((struct route *)&out_rt);
>   

You need to remember to drop the lock which rtalloc() acquires on your 
behalf using RTFREE() before leaving the function or possibly calling a 
function which needs exclusive/write access to the rtentry.

If your code needs this rtentry to remain in the system, a call to 
RT_ADDREF() with the lock held may be necessary, although you should 
remember to RT_REMREF() with the lock held when done with the rtentry.

See «net/route.h» for more info.

regards,
BMS