diff options
Diffstat (limited to 'resolv/res_send.c')
| -rw-r--r-- | resolv/res_send.c | 323 |
1 files changed, 242 insertions, 81 deletions
diff --git a/resolv/res_send.c b/resolv/res_send.c index 23306a2fb4..b3dbd702a2 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -176,10 +176,14 @@ evNowTime(struct timespec *res) { /* Forward. */ static int send_vc(res_state, const u_char *, int, - u_char **, int *, int *, int, u_char **); + const u_char *, int, + u_char **, int *, int *, int, u_char **, + u_char **, int *, int *); static int send_dg(res_state, const u_char *, int, + const u_char *, int, u_char **, int *, int *, int, - int *, int *, u_char **); + int *, int *, u_char **, + u_char **, int *, int *); #ifdef DEBUG static void Aerror(const res_state, FILE *, const char *, int, const struct sockaddr *); @@ -334,33 +338,41 @@ libresolv_hidden_def (res_queriesmatch) int __libc_res_nsend(res_state statp, const u_char *buf, int buflen, - u_char *ans, int anssiz, u_char **ansp) + const u_char *buf2, int buflen2, + u_char *ans, int anssiz, u_char **ansp, u_char **ansp2, + int *nansp2) { - int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; + int gotsomewhere, terrno, try, v_circuit, resplen, resplen2, ns, n; if (statp->nscount == 0) { __set_errno (ESRCH); return (-1); } - if (anssiz < HFIXEDSZ) { + if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) { __set_errno (EINVAL); return (-1); } - if ((statp->qhook || statp->rhook) && anssiz < MAXPACKET && ansp) { - u_char *buf = malloc (MAXPACKET); - if (buf == NULL) - return (-1); - memcpy (buf, ans, HFIXEDSZ); - *ansp = buf; - ans = buf; - anssiz = MAXPACKET; +#ifdef USE_HOOKS + if (__builtin_expect (statp->qhook || statp->rhook, 0)) { + if (anssiz < MAXPACKET && ansp) { + u_char *buf = malloc (MAXPACKET); + if (buf == NULL) + return (-1); + memcpy (buf, ans, HFIXEDSZ); + *ansp = buf; + ans = buf; + anssiz = MAXPACKET; + } } +#endif DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY), (stdout, ";; res_send()\n"), buf, buflen); - v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ; + v_circuit = ((statp->options & RES_USEVC) + || buflen > PACKETSZ + || buflen2 > PACKETSZ); gotsomewhere = 0; terrno = ETIMEDOUT; @@ -442,7 +454,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, * Some resolvers want to even out the load on their nameservers. * Note that RES_BLAST overrides RES_ROTATE. */ - if ((statp->options & RES_ROTATE) != 0 && + if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) && (statp->options & RES_BLAST) == 0) { struct sockaddr_in6 *ina; unsigned int map; @@ -479,8 +491,9 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, if (nsap == NULL) goto next_ns; - same_ns: - if (statp->qhook) { + same_ns: +#ifdef USE_HOOKS + if (__builtin_expect (statp->qhook != NULL, 0)) { int done = 0, loops = 0; do { @@ -512,6 +525,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, } } while (!done); } +#endif #ifdef DEBUG char tmpbuf[40]; @@ -521,29 +535,34 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, ns + 1, inet_ntop(AF_INET6, &nsap->sin6_addr, tmpbuf, sizeof (tmpbuf)))); - if (v_circuit) { + if (__builtin_expect (v_circuit, 0)) { /* Use VC; at most one attempt per server. */ try = statp->retry; - n = send_vc(statp, buf, buflen, &ans, &anssiz, &terrno, - ns, ansp); + n = send_vc(statp, buf, buflen, buf2, buflen2, + &ans, &anssiz, &terrno, + ns, ansp, ansp2, nansp2, &resplen2); if (n < 0) return (-1); if (n == 0) goto next_ns; - resplen = n; } else { /* Use datagrams. */ - n = send_dg(statp, buf, buflen, &ans, &anssiz, &terrno, - ns, &v_circuit, &gotsomewhere, ansp); + n = send_dg(statp, buf, buflen, buf2, buflen2, + &ans, &anssiz, &terrno, + ns, &v_circuit, &gotsomewhere, ansp, + ansp2, nansp2, &resplen2); if (n < 0) return (-1); if (n == 0) goto next_ns; if (v_circuit) + // XXX Check whether both requests failed or + // XXX whether one have been answered successfully goto same_ns; - resplen = n; } + resplen = n; + Dprint((statp->options & RES_DEBUG) || ((statp->pfcode & RES_PRF_REPLY) && (statp->pfcode & RES_PRF_HEAD1)), @@ -553,6 +572,11 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, (statp->pfcode & RES_PRF_REPLY), (stdout, "%s", ""), ans, (resplen > anssiz) ? anssiz : resplen); + if (buf2 != NULL) + DprintQ((statp->options & RES_DEBUG) || + (statp->pfcode & RES_PRF_REPLY), + (stdout, "%s", ""), + *ansp2, (resplen2 > *nansp2) ? *nansp2 : resplen2); /* * If we have temporarily opened a virtual circuit, @@ -563,7 +587,8 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, (statp->options & RES_STAYOPEN) == 0) { __res_iclose(statp, false); } - if (statp->rhook) { +#ifdef USE_HOOKS + if (__builtin_expect (statp->rhook, 0)) { int done = 0, loops = 0; do { @@ -593,6 +618,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, } while (!done); } +#endif return (resplen); next_ns: ; } /*foreach ns*/ @@ -612,7 +638,8 @@ int res_nsend(res_state statp, const u_char *buf, int buflen, u_char *ans, int anssiz) { - return __libc_res_nsend(statp, buf, buflen, ans, anssiz, NULL); + return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz, + NULL, NULL, NULL); } libresolv_hidden_def (res_nsend) @@ -620,17 +647,23 @@ libresolv_hidden_def (res_nsend) static int send_vc(res_state statp, - const u_char *buf, int buflen, u_char **ansp, int *anssizp, - int *terrno, int ns, u_char **anscp) + const u_char *buf, int buflen, const u_char *buf2, int buflen2, + u_char **ansp, int *anssizp, + int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2, + int *resplen2) { const HEADER *hp = (HEADER *) buf; + const HEADER *hp2 = (HEADER *) buf2; u_char *ans = *ansp; - int anssiz = *anssizp; + int orig_anssizp = *anssizp; + // XXX REMOVE + // int anssiz = *anssizp; HEADER *anhp = (HEADER *) ans; struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns]; int truncating, connreset, resplen, n; - struct iovec iov[2]; + struct iovec iov[4]; u_short len; + u_short len2; u_char *cp; connreset = 0; @@ -677,11 +710,19 @@ send_vc(res_state statp, /* * Send length & message */ - ns_put16((u_short)buflen, (u_char*)&len); + len = htons ((u_short) buflen); evConsIovec(&len, INT16SZ, &iov[0]); evConsIovec((void*)buf, buflen, &iov[1]); - if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, 2)) - != (INT16SZ + buflen)) { + int niov = 2; + ssize_t explen = INT16SZ + buflen; + if (buf2 != NULL) { + len2 = htons ((u_short) buflen2); + evConsIovec(&len2, INT16SZ, &iov[2]); + evConsIovec((void*)buf2, buflen2, &iov[3]); + niov = 4; + explen += INT16SZ + buflen2; + } + if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, niov)) != explen) { *terrno = errno; Perror(statp, stderr, "write failed", errno); __res_iclose(statp, false); @@ -690,6 +731,8 @@ send_vc(res_state statp, /* * Receive length & response */ + int recvresp1 = 0; + int recvresp2 = buf2 == NULL; read_len: cp = ans; len = INT16SZ; @@ -718,30 +761,66 @@ send_vc(res_state statp, } return (0); } +#ifdef _STRING_ARCH_unaligned + resplen = ntohs (*(uint16_t *) ans); +#else resplen = ns_get16(ans); - if (resplen > anssiz) { +#endif + + int *thisanssizp; + u_char **thisansp; + int *thisresplenp; + if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { + thisanssizp = anssizp; + thisansp = anscp ?: ansp; + assert (anscp != NULL || ansp2 == NULL); + thisresplenp = &resplen; + } else { + if (*anssizp != MAXPACKET) { + /* No buffer allocated for the first + reply. We can try to use the rest + of the user-provided buffer. */ + *anssizp2 = orig_anssizp - resplen; + *ansp2 = *ansp + resplen; + } else { + /* The first reply did not fit into the + user-provided buffer. Maybe the second + answer will. */ + *anssizp2 = orig_anssizp; + *ansp2 = *ansp; + } + + thisanssizp = anssizp2; + thisansp = ansp2; + thisresplenp = resplen2; + } + anhp = (HEADER *) *thisansp; + + *thisresplenp = resplen; + if (resplen > *thisanssizp) { + /* Yes, we test ANSCP here. If we have two buffers + both will be allocatable. */ if (anscp) { - ans = malloc (MAXPACKET); - if (ans == NULL) { + u_char *newp = malloc (MAXPACKET); + if (newp == NULL) { *terrno = ENOMEM; __res_iclose(statp, false); return (0); } - anssiz = MAXPACKET; - *anssizp = MAXPACKET; - *ansp = ans; - *anscp = ans; - anhp = (HEADER *) ans; + *thisanssizp = MAXPACKET; + *thisansp = newp; + anhp = (HEADER *) newp; len = resplen; } else { Dprint(statp->options & RES_DEBUG, (stdout, ";; response truncated\n") ); truncating = 1; - len = anssiz; + len = *thisanssizp; } } else len = resplen; + if (len < HFIXEDSZ) { /* * Undersized message. @@ -752,7 +831,8 @@ send_vc(res_state statp, __res_iclose(statp, false); return (0); } - cp = ans; + + cp = *thisansp; while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){ cp += n; len -= n; @@ -768,7 +848,7 @@ send_vc(res_state statp, * Flush rest of answer so connection stays in synch. */ anhp->tc = 1; - len = resplen - anssiz; + len = resplen - *thisanssizp; while (len != 0) { char junk[PACKETSZ]; @@ -787,14 +867,25 @@ send_vc(res_state statp, * itself confused, then drop the packet and * wait for the correct one. */ - if (hp->id != anhp->id) { + if ((recvresp1 || hp->id != anhp->id) + && (recvresp2 || hp2->id != anhp->id)) { DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY), (stdout, ";; old answer (unexpected):\n"), - ans, (resplen > anssiz) ? anssiz: resplen); + *thisansp, + (resplen > *thisanssiz) ? *thisanssiz: resplen); goto read_len; } + /* Mark which reply we received. */ + if (recvresp1 == 0 && hp->id == anhp->id) + recvresp1 = 1; + else + recvresp2 = 1; + /* Repeat waiting if we have a second answer to arrive. */ + if ((recvresp1 & recvresp2) == 0) + goto read_len; + /* * All is well, or the error is fatal. Signal that the * next nameserver ought not be tried. @@ -804,19 +895,20 @@ send_vc(res_state statp, static int send_dg(res_state statp, - const u_char *buf, int buflen, u_char **ansp, int *anssizp, - int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp) + const u_char *buf, int buflen, const u_char *buf2, int buflen2, + u_char **ansp, int *anssizp, + int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp, + u_char **ansp2, int *anssizp2, int *resplen2) { const HEADER *hp = (HEADER *) buf; + const HEADER *hp2 = (HEADER *) buf2; u_char *ans = *ansp; - int anssiz = *anssizp; - HEADER *anhp = (HEADER *) ans; + int orig_anssizp = *anssizp; struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns]; struct timespec now, timeout, finish; struct pollfd pfd[1]; int ptimeout; struct sockaddr_in6 from; - socklen_t fromlen; int resplen, seconds, n; if (EXT(statp).nssocks[ns] == -1) { @@ -879,6 +971,8 @@ send_dg(res_state statp, evAddTime(&finish, &now, &timeout); int need_recompute = 0; int nwritten = 0; + int recvresp1 = 0; + int recvresp2 = buf2 == NULL; pfd[0].fd = EXT(statp).nssocks[ns]; pfd[0].events = POLLOUT; wait: @@ -918,35 +1012,73 @@ send_dg(res_state statp, } __set_errno (0); if (pfd[0].revents & POLLOUT) { - if (send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL) != buflen) { + ssize_t sr; + if (nwritten != 0) + sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL); + else + sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL); + + if (sr != buflen) { if (errno == EINTR || errno == EAGAIN) goto recompute_resend; Perror(statp, stderr, "send", errno); goto err_out; } - pfd[0].events = POLLIN; + if (nwritten != 0 || buf2 == NULL) + pfd[0].events = POLLIN; + else + pfd[0].events = POLLIN | POLLOUT; ++nwritten; goto wait; } else if (pfd[0].revents & POLLIN) { - fromlen = sizeof(struct sockaddr_in6); - if (anssiz < MAXPACKET + int *thisanssizp; + u_char **thisansp; + int *thisresplenp; + + if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { + thisanssizp = anssizp; + thisansp = anscp ?: ansp; + assert (anscp != NULL || ansp2 == NULL); + thisresplenp = &resplen; + } else { + if (*anssizp != MAXPACKET) { + /* No buffer allocated for the first + reply. We can try to use the rest + of the user-provided buffer. */ + *anssizp2 = orig_anssizp - resplen; + *ansp2 = *ansp + resplen; + } else { + /* The first reply did not fit into the + user-provided buffer. Maybe the second + answer will. */ + *anssizp2 = orig_anssizp; + *ansp2 = *ansp; + } + + thisanssizp = anssizp2; + thisansp = ansp2; + thisresplenp = resplen2; + } + + if (*thisanssizp < MAXPACKET + /* Yes, we test ANSCP here. If we have two buffers + both will be allocatable. */ && anscp - && (ioctl (pfd[0].fd, FIONREAD, &resplen) < 0 - || anssiz < resplen)) { - ans = malloc (MAXPACKET); - if (ans == NULL) - ans = *ansp; - else { - anssiz = MAXPACKET; + && (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0 + || *thisanssizp < *thisresplenp)) { + u_char *newp = malloc (MAXPACKET); + if (newp != NULL) { *anssizp = MAXPACKET; - *ansp = ans; - *anscp = ans; - anhp = (HEADER *) ans; + *thisansp = ans = newp; } } - resplen = recvfrom(pfd[0].fd, (char*)ans, anssiz,0, - (struct sockaddr *)&from, &fromlen); - if (resplen <= 0) { + HEADER *anhp = (HEADER *) *thisansp; + socklen_t fromlen = sizeof(struct sockaddr_in6); + assert (sizeof(from) <= fromlen); + *thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp, + *thisanssizp, 0, + (struct sockaddr *)&from, &fromlen); + if (*thisresplenp <= 0) { if (errno == EINTR || errno == EAGAIN) { need_recompute = 1; goto wait; @@ -955,17 +1087,18 @@ send_dg(res_state statp, goto err_out; } *gotsomewhere = 1; - if (resplen < HFIXEDSZ) { + if (*thisresplenp < HFIXEDSZ) { /* * Undersized message. */ Dprint(statp->options & RES_DEBUG, (stdout, ";; undersized: %d\n", - resplen)); + *thisresplen)); *terrno = EMSGSIZE; goto err_out; } - if (hp->id != anhp->id) { + if ((recvresp1 || hp->id != anhp->id) + && (recvresp2 || hp2->id != anhp->id)) { /* * response from old query, ignore it. * XXX - potential security hazard could @@ -974,7 +1107,9 @@ send_dg(res_state statp, DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY), (stdout, ";; old answer:\n"), - ans, (resplen > anssiz) ? anssiz : resplen); + thisansp, + (*thisresplen > *thisanssiz) + ? *thisanssiz : *thisresplen); goto wait; } if (!(statp->options & RES_INSECURE1) && @@ -987,14 +1122,16 @@ send_dg(res_state statp, DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY), (stdout, ";; not our server:\n"), - ans, (resplen > anssiz) ? anssiz : resplen); + thisansp, + (*thisresplen > *thisanssiz) + ? *thisanssiz : *thisresplen); goto wait; } #ifdef RES_USE_EDNS0 if (anhp->rcode == FORMERR && (statp->options & RES_USE_EDNS0) != 0U) { /* - * Do not retry if the server do not understand + * Do not retry if the server does not understand * EDNS0. The case has to be captured here, as * FORMERR packet do not carry query section, hence * res_queriesmatch() returns 0. @@ -1002,15 +1139,23 @@ send_dg(res_state statp, DprintQ(statp->options & RES_DEBUG, (stdout, "server rejected query with EDNS0:\n"), - ans, (resplen > anssiz) ? anssiz : resplen); + thisans, + (*thisresplen > *thisanssiz) + ? *thisanssiz : *thisresplen); /* record the error */ statp->_flags |= RES_F_EDNS0ERR; goto err_out; } #endif - if (!(statp->options & RES_INSECURE2) && - !res_queriesmatch(buf, buf + buflen, - ans, ans + anssiz)) { + if (!(statp->options & RES_INSECURE2) + && (recvresp1 || !res_queriesmatch(buf, buf + buflen, + *thisansp, + *thisansp + + *thisanssizp)) + && (recvresp2 || !res_queriesmatch(buf2, buf2 + buflen2, + *thisansp, + *thisansp + + *thisanssizp))) { /* * response contains wrong query? ignore it. * XXX - potential security hazard could @@ -1019,7 +1164,9 @@ send_dg(res_state statp, DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY), (stdout, ";; wrong query name:\n"), - ans, (resplen > anssiz) ? anssiz : resplen); + thisansp, + (*thisresplen > *thisanssiz) + ? *thisanssiz : *thisresplen); goto wait; } if (anhp->rcode == SERVFAIL || @@ -1027,7 +1174,9 @@ send_dg(res_state statp, anhp->rcode == REFUSED) { DprintQ(statp->options & RES_DEBUG, (stdout, "server rejected query:\n"), - ans, (resplen > anssiz) ? anssiz : resplen); + thisansp, + (*thisresplen > *thisanssiz) + ? *thisanssiz : *thisresplen); next_ns: __res_iclose(statp, false); /* don't retry if called from dig */ @@ -1038,7 +1187,9 @@ send_dg(res_state statp, && anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) { DprintQ(statp->options & RES_DEBUG, (stdout, "referred query:\n"), - ans, (resplen > anssiz) ? anssiz : resplen); + thisansp, + (*thisresplen > *thisanssiz) + ? *thisanssiz : *thisresplen); goto next_ns; } if (!(statp->options & RES_IGNTC) && anhp->tc) { @@ -1050,8 +1201,18 @@ send_dg(res_state statp, (stdout, ";; truncated answer\n")); *v_circuit = 1; __res_iclose(statp, false); + // XXX if we have received one reply we could + // XXX use it and not repeat it over TCP... return (1); } + /* Mark which reply we received. */ + if (recvresp1 == 0 && hp->id == anhp->id) + recvresp1 = 1; + else + recvresp2 = 1; + /* Repeat waiting if we have a second answer to arrive. */ + if ((recvresp1 & recvresp2) == 0) + goto wait; /* * All is well, or the error is fatal. Signal that the * next nameserver ought not be tried. |