diff --git a/ChangeLog b/ChangeLog index 609873854e..7f629acced 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2016-03-25 Florian Weimer + + [BZ #19791] + * resolv/res_send.c (close_and_return_error): New function. + (send_dg): Initialize *resplen2 after reopen failure. Call + close_and_return_error for error returns. On error paths without + __res_iclose, initialze *resplen2 explicitly. Update comment for + successful return. + 2016-03-25 Florian Weimer [BZ# 19860] diff --git a/resolv/res_send.c b/resolv/res_send.c index 25c19f12c3..b4efcb64a0 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -649,6 +649,18 @@ get_nsaddr (res_state statp, int n) return (struct sockaddr *) (void *) &statp->nsaddr_list[n]; } +/* Close the resolver structure, assign zero to *RESPLEN2 if RESPLEN2 + is not NULL, and return zero. */ +static int +__attribute__ ((warn_unused_result)) +close_and_return_error (res_state statp, int *resplen2) +{ + __res_iclose(statp, false); + if (resplen2 != NULL) + *resplen2 = 0; + return 0; +} + /* The send_vc function is responsible for sending a DNS query over TCP to the nameserver numbered NS from the res_state STATP i.e. EXT(statp).nssocks[ns]. The function supports sending both IPv4 and @@ -1114,7 +1126,11 @@ send_dg(res_state statp, retry_reopen: retval = reopen (statp, terrno, ns); if (retval <= 0) - return retval; + { + if (resplen2 != NULL) + *resplen2 = 0; + return retval; + } retry: evNowTime(&now); evConsTime(&timeout, seconds, 0); @@ -1127,8 +1143,6 @@ send_dg(res_state statp, int recvresp2 = buf2 == NULL; pfd[0].fd = EXT(statp).nssocks[ns]; pfd[0].events = POLLOUT; - if (resplen2 != NULL) - *resplen2 = 0; wait: if (need_recompute) { recompute_resend: @@ -1136,9 +1150,7 @@ send_dg(res_state statp, if (evCmpTime(finish, now) <= 0) { poll_err_out: Perror(statp, stderr, "poll", errno); - err_out: - __res_iclose(statp, false); - return (0); + return close_and_return_error (statp, resplen2); } evSubTime(&timeout, &finish, &now); need_recompute = 0; @@ -1185,7 +1197,9 @@ send_dg(res_state statp, } *gotsomewhere = 1; - return (0); + if (resplen2 != NULL) + *resplen2 = 0; + return 0; } if (n < 0) { if (errno == EINTR) @@ -1253,7 +1267,7 @@ send_dg(res_state statp, fail_sendmmsg: Perror(statp, stderr, "sendmmsg", errno); - goto err_out; + return close_and_return_error (statp, resplen2); } } else @@ -1271,7 +1285,7 @@ send_dg(res_state statp, if (errno == EINTR || errno == EAGAIN) goto recompute_resend; Perror(statp, stderr, "send", errno); - goto err_out; + return close_and_return_error (statp, resplen2); } just_one: if (nwritten != 0 || buf2 == NULL || single_request) @@ -1349,7 +1363,7 @@ send_dg(res_state statp, goto wait; } Perror(statp, stderr, "recvfrom", errno); - goto err_out; + return close_and_return_error (statp, resplen2); } *gotsomewhere = 1; if (__glibc_unlikely (*thisresplenp < HFIXEDSZ)) { @@ -1360,7 +1374,7 @@ send_dg(res_state statp, (stdout, ";; undersized: %d\n", *thisresplenp)); *terrno = EMSGSIZE; - goto err_out; + return close_and_return_error (statp, resplen2); } if ((recvresp1 || hp->id != anhp->id) && (recvresp2 || hp2->id != anhp->id)) { @@ -1409,7 +1423,7 @@ send_dg(res_state statp, ? *thisanssizp : *thisresplenp); /* record the error */ statp->_flags |= RES_F_EDNS0ERR; - goto err_out; + return close_and_return_error (statp, resplen2); } #endif if (!(statp->options & RES_INSECURE2) @@ -1461,10 +1475,10 @@ send_dg(res_state statp, goto wait; } - __res_iclose(statp, false); /* don't retry if called from dig */ if (!statp->pfcode) - return (0); + return close_and_return_error (statp, resplen2); + __res_iclose(statp, false); } if (anhp->rcode == NOERROR && anhp->ancount == 0 && anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) { @@ -1486,6 +1500,8 @@ send_dg(res_state statp, __res_iclose(statp, false); // XXX if we have received one reply we could // XXX use it and not repeat it over TCP... + if (resplen2 != NULL) + *resplen2 = 0; return (1); } /* Mark which reply we received. */ @@ -1501,21 +1517,22 @@ send_dg(res_state statp, __res_iclose (statp, false); retval = reopen (statp, terrno, ns); if (retval <= 0) - return retval; + { + if (resplen2 != NULL) + *resplen2 = 0; + return retval; + } pfd[0].fd = EXT(statp).nssocks[ns]; } } goto wait; } - /* - * All is well, or the error is fatal. Signal that the - * next nameserver ought not be tried. - */ + /* All is well. We have received both responses (if + two responses were requested). */ return (resplen); - } else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) { - /* Something went wrong. We can stop trying. */ - goto err_out; - } + } else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) + /* Something went wrong. We can stop trying. */ + return close_and_return_error (statp, resplen2); else { /* poll should not have returned > 0 in this case. */ abort ();