diff options
Diffstat (limited to 'resolv/res_query.c')
| -rw-r--r-- | resolv/res_query.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/resolv/res_query.c b/resolv/res_query.c index 85bad97d2d..4371af5b05 100644 --- a/resolv/res_query.c +++ b/resolv/res_query.c @@ -120,10 +120,13 @@ __libc_res_nquery(res_state statp, u_char *buf; HEADER *hp = (HEADER *) answer; int n, use_malloc = 0; + u_int oflags = statp->_flags; - hp->rcode = NOERROR; /* default */ + size_t bufsize = QUERYSIZE; + buf = alloca (bufsize); - buf = alloca (QUERYSIZE); + again: + hp->rcode = NOERROR; /* default */ #ifdef DEBUG if (statp->options & RES_DEBUG) @@ -131,18 +134,30 @@ __libc_res_nquery(res_state statp, #endif n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL, - buf, QUERYSIZE); - if (__builtin_expect (n <= 0, 0)) { + buf, bufsize); + if (n > 0 + && (oflags & RES_F_EDNS0ERR) == 0 + && (statp->options & RES_USE_EDNS0) != 0) + n = __res_nopt(statp, n, buf, bufsize, anslen); + if (__builtin_expect (n <= 0, 0) && !use_malloc) { /* Retry just in case res_nmkquery failed because of too short buffer. Shouldn't happen. */ - buf = malloc (MAXPACKET); + bufsize = MAXPACKET; + buf = malloc (bufsize); if (buf != NULL) { use_malloc = 1; - n = res_nmkquery(statp, QUERY, name, class, type, NULL, - 0, NULL, buf, MAXPACKET); + goto again; } } if (__builtin_expect (n <= 0, 0)) { + /* If the query choked with EDNS0, retry without EDNS0. */ + if ((statp->options & RES_USE_EDNS0) != 0 + && ((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) { + statp->_flags |= RES_F_EDNS0ERR; + if (statp->options & RES_DEBUG) + printf(";; res_nquery: retry without EDNS0\n"); + goto again; + } #ifdef DEBUG if (statp->options & RES_DEBUG) printf(";; res_query: mkquery failed\n"); |