diff options
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/net/getaddrinfo.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/libc/net/getaddrinfo.c b/lib/libc/net/getaddrinfo.c index d987a16..c5bfc5e 100644 --- a/lib/libc/net/getaddrinfo.c +++ b/lib/libc/net/getaddrinfo.c @@ -207,6 +207,7 @@ struct ai_order { struct policyqueue *aio_dstpolicy; struct addrinfo *aio_ai; int aio_matchlen; + int aio_initial_sequence; }; static const ns_src default_dns_files[] = { @@ -690,6 +691,7 @@ reorder(struct addrinfo *sentinel) aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, &policyhead); set_source(&aio[i], &policyhead); + aio[i].aio_initial_sequence = i; } /* perform sorting. */ @@ -1048,6 +1050,23 @@ comp_dst(const void *arg1, const void *arg2) } /* Rule 10: Otherwise, leave the order unchanged. */ + + /* + * Note that qsort is unstable; so, we can't return zero and + * expect the order to be unchanged. + * That also means we can't depend on the current position of + * dst2 being after dst1. We must enforce the initial order + * with an explicit compare on the original position. + * The qsort specification requires that "When the same objects + * (consisting of width bytes, irrespective of their current + * positions in the array) are passed more than once to the + * comparison function, the results shall be consistent with one + * another." + * In other words, If A < B, then we must also return B > A. + */ + if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) + return(1); + return(-1); } |
