From 0420d8885a4889dca3b874c934fd5f42f2e99e5f Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Thu, 17 Oct 2002 21:51:21 +0000 Subject: Update. 2002-10-15 Jakub Jelinek * include/resolv.h (__libc_res_nquery, __libc_res_nsearch, __libc_res_nsend): New prototypes. * resolv/res_query.c (QUERYSIZE): Define. (__libc_res_nquery): Renamed from res_nquery. Added answerp argument. Allocate only QUERYSIZE bytes first, if res_nmkquery fails use MAXPACKET buffer. Call __libc_res_nsend instead of res_nsend, pass answerp. (res_nquery): Changed into wrapper around __libc_res_nquery. (__libc_res_nsearch): Renamed from res_nsearch. Added answerp argument. Call __libc_res_nquerydomain and __libc_res_nquery instead of the non-__libc_ variants, pass them answerp. (res_nsearch): Changed into wrapper around __libc_res_nsearch. (__libc_res_nquerydomain): Renamed from res_nquerydomain. Added answerp argument. Call __libc_res_nquery instead of res_nquery, pass answerp. (res_nquerydomain): Changed into wrapper around __libc_res_nquerydomain. * resolv/res_send.c: Include sys/ioctl.h. (MAXPACKET): Define. (send_vc): Change arguments. Reallocate answer buffer if it is too small. (send_dg): Likewise. (__libc_res_nsend): Renamed from res_nsend. Added ansp argument. Reallocate answer buffer if it is too small and hooks are in use. Adjust calls to send_vc and send_dg. (res_nsend): Changed into wrapper around __libc_res_nsend. * resolv/nss_dns/dns-host.c (_nss_dns_gethostbyname2_r): Allocate just 1K answer buffer on the stack, use __libc_res_nsearch instead of res_nsearch. (_nss_dns_gethostbyaddr_r): Similarly with __libc_res_nquery. * resolv/nss_dns/dns-network.c (_nss_dns_getnetbyaddr_r): Likewise. (_nss_dns_getnetbyname_r): Similarly with __libc_res_nsearch. * resolv/gethnamaddr.c (gethostbyname2): Likewise. (gethostbyaddr): Similarly with __libc_res_nquery. * resolv/Versions (libresolv): Export __libc_res_nquery and __libc_res_nsearch at GLIBC_PRIVATE. --- resolv/Versions | 1 + resolv/gethnamaddr.c | 46 +++++++---------- resolv/nss_dns/dns-host.c | 60 ++++++++-------------- resolv/nss_dns/dns-network.c | 50 +++++------------- resolv/res_query.c | 119 ++++++++++++++++++++++++++++++++----------- resolv/res_send.c | 96 +++++++++++++++++++++++++++------- 6 files changed, 219 insertions(+), 153 deletions(-) (limited to 'resolv') diff --git a/resolv/Versions b/resolv/Versions index ab6a386802..09dca6aa2a 100644 --- a/resolv/Versions +++ b/resolv/Versions @@ -72,6 +72,7 @@ libresolv { # Needed in libnss_dns. __ns_name_unpack; __ns_name_ntop; __ns_get16; __ns_samename; + __libc_res_nquery; __libc_res_nsearch; } } diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c index 797af94874..e941b5c1ac 100644 --- a/resolv/gethnamaddr.c +++ b/resolv/gethnamaddr.c @@ -510,10 +510,10 @@ gethostbyname2(name, af) const char *name; int af; { - querybuf *buf; + querybuf *buf, *origbuf; register const char *cp; char *bp; - int n, size, type, len, use_malloc = 0; + int n, size, type, len; struct hostent *ret; extern struct hostent *_gethtbyname2(); @@ -616,24 +616,19 @@ gethostbyname2(name, af) break; } - if (!__libc_use_alloca (MAXPACKET)) { - buf = (querybuf *) malloc (sizeof (*buf)); - if (buf == NULL) { - __set_h_errno (NETDB_INTERNAL); - return NULL; - } - use_malloc = 1; - } else - buf = (querybuf *) alloca (sizeof (*buf)); + buf = origbuf = (querybuf *) alloca (1024); - if ((n = res_nsearch(&_res, name, C_IN, type, buf->buf, sizeof(buf->buf))) < 0) { + if ((n = __libc_res_nsearch(&_res, name, C_IN, type, buf->buf, 1024, + (u_char **) &buf)) < 0) { + if (buf != origbuf) + free (buf); dprintf("res_nsearch failed (%d)\n", n); if (errno == ECONNREFUSED) return (_gethtbyname2(name, af)); return (NULL); } ret = getanswer(buf, n, name, type); - if (use_malloc) + if (buf != origbuf) free (buf); return ret; } @@ -647,9 +642,9 @@ gethostbyaddr(addr, len, af) const u_char *uaddr = (const u_char *)addr; static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; - int n, use_malloc = 0; + int n; socklen_t size; - querybuf *buf; + querybuf *buf, *orig_buf; register struct hostent *hp; char qbuf[MAXDNAME+1], *qp = NULL; #ifdef SUNSECURITY @@ -711,23 +706,18 @@ gethostbyaddr(addr, len, af) abort(); } - if (!__libc_use_alloca (MAXPACKET)) { - buf = (querybuf *) malloc (sizeof (*buf)); - if (buf == NULL) { - __set_h_errno (NETDB_INTERNAL); - return NULL; - } - use_malloc = 1; - } else - buf = (querybuf *) alloca (sizeof (*buf)); + buf = orig_buf = (querybuf *) alloca (1024); - n = res_nquery(&_res, qbuf, C_IN, T_PTR, buf->buf, sizeof buf->buf); + n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf->buf, 1024, + (u_char **) &buf); if (n < 0 && af == AF_INET6) { strcpy(qp, "ip6.int"); - n = res_nquery(&_res, qbuf, C_IN, T_PTR, buf->buf, sizeof buf->buf); + n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf->buf, + buf != orig_buf ? MAXPACKET : 1024, + (u_char **) &buf); } if (n < 0) { - if (use_malloc) + if (buf != orig_buf) free (buf); dprintf("res_nquery failed (%d)\n", n); if (errno == ECONNREFUSED) @@ -735,7 +725,7 @@ gethostbyaddr(addr, len, af) return (NULL); } hp = getanswer(buf, n, qbuf, T_PTR); - if (use_malloc) + if (buf != orig_buf) free (buf); if (!hp) return (NULL); /* h_errno was set by getanswer() */ diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c index 39eccabbdf..b01dc54993 100644 --- a/resolv/nss_dns/dns-host.c +++ b/resolv/nss_dns/dns-host.c @@ -132,11 +132,11 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop) { - querybuf *host_buffer; + querybuf *host_buffer, *orig_host_buffer; char tmp[NS_MAXDNAME]; int size, type, n; const char *cp; - int map = 0, use_malloc = 0; + int map = 0; int olderr = errno; enum nss_status status; @@ -170,21 +170,10 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result, && (cp = res_hostalias (&_res, name, tmp, sizeof (tmp))) != NULL) name = cp; - if (!__libc_use_alloca (MAXPACKET)) - { - host_buffer = (querybuf *) malloc (sizeof (querybuf)); - if (host_buffer == NULL) - { - *errnop = ENOMEM; - return NSS_STATUS_UNAVAIL; - } - use_malloc = 1; - } - else - host_buffer = (querybuf *) alloca (sizeof (querybuf)); + host_buffer = orig_host_buffer = (querybuf *) alloca (1024); - n = res_nsearch (&_res, name, C_IN, type, host_buffer->buf, - sizeof (host_buffer->buf)); + n = __libc_res_nsearch (&_res, name, C_IN, type, host_buffer->buf, + 1024, (u_char **) &host_buffer); if (n < 0) { enum nss_status status = (errno == ECONNREFUSED @@ -199,12 +188,13 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result, by having the RES_USE_INET6 bit in _res.options set, we try another lookup. */ if (af == AF_INET6 && (_res.options & RES_USE_INET6)) - n = res_nsearch (&_res, name, C_IN, T_A, host_buffer->buf, - sizeof (host_buffer->buf)); + n = __libc_res_nsearch (&_res, name, C_IN, T_A, host_buffer->buf, + host_buffer != orig_host_buffer + ? MAXPACKET : 1024, (u_char **) &host_buffer); if (n < 0) { - if (use_malloc) + if (host_buffer != orig_host_buffer) free (host_buffer); return status; } @@ -217,7 +207,7 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result, status = getanswer_r (host_buffer, n, name, type, result, buffer, buflen, errnop, h_errnop, map); - if (use_malloc) + if (host_buffer != orig_host_buffer) free (host_buffer); return status; } @@ -257,10 +247,10 @@ _nss_dns_gethostbyaddr_r (const void *addr, socklen_t len, int af, char *h_addr_ptrs[MAX_NR_ADDRS + 1]; char linebuffer[0]; } *host_data = (struct host_data *) buffer; - querybuf *host_buffer; + querybuf *host_buffer, *orig_host_buffer; char qbuf[MAXDNAME+1], *qp = NULL; size_t size; - int n, status, use_malloc = 0; + int n, status; int olderr = errno; if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1) @@ -315,39 +305,29 @@ _nss_dns_gethostbyaddr_r (const void *addr, socklen_t len, int af, break; } - if (!__libc_use_alloca (MAXPACKET)) - { - host_buffer = (querybuf *) malloc (sizeof (querybuf)); - if (host_buffer == NULL) - { - *errnop = ENOMEM; - return NSS_STATUS_UNAVAIL; - } - use_malloc = 1; - } - else - host_buffer = (querybuf *) alloca (sizeof (querybuf)); + host_buffer = orig_host_buffer = (querybuf *) alloca (1024); - n = res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer->buf, - sizeof (host_buffer->buf)); + n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer->buf, + 1024, (u_char **) &host_buffer); if (n < 0 && af == AF_INET6) { strcpy (qp, "ip6.int"); - n = res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer->buf, - sizeof (host_buffer->buf)); + n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer->buf, + host_buffer != orig_host_buffer + ? MAXPACKET : 1024, (u_char **) &host_buffer); } if (n < 0) { *h_errnop = h_errno; __set_errno (olderr); - if (use_malloc) + if (host_buffer != orig_host_buffer) free (host_buffer); return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND; } status = getanswer_r (host_buffer, n, qbuf, T_PTR, result, buffer, buflen, errnop, h_errnop, 0 /* XXX */); - if (use_malloc) + if (host_buffer != orig_host_buffer) free (host_buffer); if (status != NSS_STATUS_SUCCESS) { diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c index 9a366aca65..5956c84382 100644 --- a/resolv/nss_dns/dns-network.c +++ b/resolv/nss_dns/dns-network.c @@ -110,8 +110,8 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result, int *herrnop) { /* Return entry for network with NAME. */ - querybuf *net_buffer; - int anslen, use_malloc = 0; + querybuf *net_buffer, *orig_net_buffer; + int anslen; char *qbuf; enum nss_status status; @@ -120,26 +120,15 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result, qbuf = strdupa (name); - if (!__libc_use_alloca (MAXPACKET)) - { - net_buffer = (querybuf *) malloc (sizeof (querybuf)); - if (net_buffer == NULL) - { - *errnop = ENOMEM; - return NSS_STATUS_UNAVAIL; - } - use_malloc = 1; - } - else - net_buffer = (querybuf *) alloca (sizeof (querybuf)); + net_buffer = orig_net_buffer = (querybuf *) alloca (1024); - anslen = res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer->buf, - sizeof (net_buffer->buf)); + anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer->buf, + 1024, (u_char **) &net_buffer); if (anslen < 0) { /* Nothing found. */ *errnop = errno; - if (use_malloc) + if (net_buffer != orig_net_buffer) free (net_buffer); return (errno == ECONNREFUSED || errno == EPFNOSUPPORT @@ -148,7 +137,7 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result, } status = getanswer_r (net_buffer, anslen, result, buffer, buflen, BYNAME); - if (use_malloc) + if (net_buffer != orig_net_buffer) free (net_buffer); return status; } @@ -161,10 +150,10 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result, { /* Return entry for network with NAME. */ enum nss_status status; - querybuf *net_buffer; + querybuf *net_buffer, *orig_net_buffer; unsigned int net_bytes[4]; char qbuf[MAXDNAME]; - int cnt, anslen, use_malloc = 0; + int cnt, anslen; u_int32_t net2; int olderr = errno; @@ -201,27 +190,16 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result, break; } - if (!__libc_use_alloca (MAXPACKET)) - { - net_buffer = (querybuf *) malloc (sizeof (querybuf)); - if (net_buffer == NULL) - { - *errnop = ENOMEM; - return NSS_STATUS_UNAVAIL; - } - use_malloc = 1; - } - else - net_buffer = (querybuf *) alloca (sizeof (querybuf)); + net_buffer = orig_net_buffer = (querybuf *) alloca (1024); - anslen = res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer->buf, - sizeof (net_buffer->buf)); + anslen = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer->buf, + 1024, (u_char **) &net_buffer); if (anslen < 0) { /* Nothing found. */ int err = errno; __set_errno (olderr); - if (use_malloc) + if (net_buffer != orig_net_buffer) free (net_buffer); return (err == ECONNREFUSED || err == EPFNOSUPPORT @@ -230,7 +208,7 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result, } status = getanswer_r (net_buffer, anslen, result, buffer, buflen, BYADDR); - if (use_malloc) + if (net_buffer != orig_net_buffer) free (net_buffer); if (status == NSS_STATUS_SUCCESS) { diff --git a/resolv/res_query.c b/resolv/res_query.c index 968ba8b4e8..ab4e02a559 100644 --- a/resolv/res_query.c +++ b/resolv/res_query.c @@ -91,6 +91,13 @@ static const char rcsid[] = "$BINDId: res_query.c,v 8.20 2000/02/29 05:39:12 vix #define MAXPACKET 65536 #endif +#define QUERYSIZE (HFIXEDSZ + QFIXEDSZ + MAXCDNAME + 1) + +static int +__libc_res_nquerydomain(res_state statp, const char *name, const char *domain, + int class, int type, u_char *answer, int anslen, + u_char **answerp); + /* * Formulate a normal query, send, and await answer. * Returned answer is placed in supplied buffer "answer". @@ -102,11 +109,12 @@ static const char rcsid[] = "$BINDId: res_query.c,v 8.20 2000/02/29 05:39:12 vix * Caller must parse answer and determine whether it answers the question. */ int -res_nquery(res_state statp, - const char *name, /* domain name */ - int class, int type, /* class and type of query */ - u_char *answer, /* buffer to put answer */ - int anslen) /* size of answer buffer */ +__libc_res_nquery(res_state statp, + const char *name, /* domain name */ + int class, int type, /* class and type of query */ + u_char *answer, /* buffer to put answer */ + int anslen, /* size of answer buffer */ + u_char **answerp) /* if buffer needs to be enlarged */ { u_char *buf; HEADER *hp = (HEADER *) answer; @@ -114,15 +122,7 @@ res_nquery(res_state statp, hp->rcode = NOERROR; /* default */ - if (!__libc_use_alloca (MAXPACKET)) { - buf = malloc (MAXPACKET); - if (buf == NULL) { - __set_h_errno (NETDB_INTERNAL); - return -1; - } - use_malloc = 1; - } else - buf = alloca (MAXPACKET); + buf = alloca (QUERYSIZE); #ifdef DEBUG if (statp->options & RES_DEBUG) @@ -130,8 +130,18 @@ res_nquery(res_state statp, #endif n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL, - buf, MAXPACKET); - if (n <= 0) { + buf, QUERYSIZE); + if (__builtin_expect (n <= 0, 0)) { + /* Retry just in case res_nmkquery failed because of too + short buffer. Shouldn't happen. */ + buf = malloc (MAXPACKET); + if (buf != NULL) { + use_malloc = 1; + n = res_nmkquery(statp, QUERY, name, class, type, NULL, + 0, NULL, buf, MAXPACKET); + } + } + if (__builtin_expect (n <= 0, 0)) { #ifdef DEBUG if (statp->options & RES_DEBUG) printf(";; res_query: mkquery failed\n"); @@ -141,7 +151,7 @@ res_nquery(res_state statp, free (buf); return (n); } - n = res_nsend(statp, buf, n, answer, anslen); + n = __libc_res_nsend(statp, buf, n, answer, anslen, answerp); if (use_malloc) free (buf); if (n < 0) { @@ -181,6 +191,17 @@ res_nquery(res_state statp, return (n); } +int +res_nquery(res_state statp, + const char *name, /* domain name */ + int class, int type, /* class and type of query */ + u_char *answer, /* buffer to put answer */ + int anslen) /* size of answer buffer */ +{ + return __libc_res_nquery(statp, name, class, type, answer, anslen, + NULL); +} + /* * Formulate a normal query, send, and retrieve answer in supplied buffer. * Return the size of the response on success, -1 on error. @@ -188,11 +209,12 @@ res_nquery(res_state statp, * is detected. Error code, if any, is left in H_ERRNO. */ int -res_nsearch(res_state statp, +__libc_res_nsearch(res_state statp, const char *name, /* domain name */ int class, int type, /* class and type of query */ u_char *answer, /* buffer to put answer */ - int anslen) /* size of answer */ + int anslen, /* size of answer */ + u_char **answerp) { const char *cp, * const *domain; HEADER *hp = (HEADER *) answer; @@ -214,7 +236,8 @@ res_nsearch(res_state statp, /* If there aren't any dots, it could be a user-level alias. */ if (!dots && (cp = res_hostalias(statp, name, tmp, sizeof tmp))!= NULL) - return (res_nquery(statp, cp, class, type, answer, anslen)); + return (__libc_res_nquery(statp, cp, class, type, answer, + anslen, answerp)); /* * If there are enough dots in the name, let's just give it a @@ -223,12 +246,16 @@ res_nsearch(res_state statp, */ saved_herrno = -1; if (dots >= statp->ndots || trailing_dot) { - ret = res_nquerydomain(statp, name, NULL, class, type, - answer, anslen); + ret = __libc_res_nquerydomain(statp, name, NULL, class, type, + answer, anslen, answerp); if (ret > 0 || trailing_dot) return (ret); saved_herrno = h_errno; tried_as_is++; + if (answerp && *answerp != answer) { + answer = *answerp; + anslen = MAXPACKET; + } } /* @@ -249,12 +276,17 @@ res_nsearch(res_state statp, (domain[0][0] == '.' && domain[0][1] == '\0')) root_on_list++; - ret = res_nquerydomain(statp, name, *domain, - class, type, - answer, anslen); + ret = __libc_res_nquerydomain(statp, name, *domain, + class, type, + answer, anslen, answerp); if (ret > 0) return (ret); + if (answerp && *answerp != answer) { + answer = *answerp; + anslen = MAXPACKET; + } + /* * If no server present, give up. * If name isn't found in this domain, @@ -306,8 +338,8 @@ res_nsearch(res_state statp, * query now. */ if (statp->ndots && !(tried_as_is || root_on_list)) { - ret = res_nquerydomain(statp, name, NULL, class, type, - answer, anslen); + ret = __libc_res_nquerydomain(statp, name, NULL, class, type, + answer, anslen, answerp); if (ret > 0) return (ret); } @@ -328,17 +360,29 @@ res_nsearch(res_state statp, return (-1); } +int +res_nsearch(res_state statp, + const char *name, /* domain name */ + int class, int type, /* class and type of query */ + u_char *answer, /* buffer to put answer */ + int anslen) /* size of answer */ +{ + return __libc_res_nsearch(statp, name, class, type, answer, + anslen, NULL); +} + /* * Perform a call on res_query on the concatenation of name and domain, * removing a trailing dot from name if domain is NULL. */ -int -res_nquerydomain(res_state statp, +static int +__libc_res_nquerydomain(res_state statp, const char *name, const char *domain, int class, int type, /* class and type of query */ u_char *answer, /* buffer to put answer */ - int anslen) /* size of answer */ + int anslen, /* size of answer */ + u_char **answerp) { char nbuf[MAXDNAME]; const char *longname = nbuf; @@ -374,7 +418,20 @@ res_nquerydomain(res_state statp, } sprintf(nbuf, "%s.%s", name, domain); } - return (res_nquery(statp, longname, class, type, answer, anslen)); + return (__libc_res_nquery(statp, longname, class, type, answer, + anslen, answerp)); +} + +int +res_nquerydomain(res_state statp, + const char *name, + const char *domain, + int class, int type, /* class and type of query */ + u_char *answer, /* buffer to put answer */ + int anslen) /* size of answer */ +{ + return __libc_res_nquerydomain(statp, name, domain, class, type, + answer, anslen, NULL); } const char * diff --git a/resolv/res_send.c b/resolv/res_send.c index a163d06a0a..d237c9a537 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -85,6 +85,7 @@ static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixi #include #include #include +#include #include #include @@ -95,6 +96,12 @@ static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixi #include #include +#if PACKETSZ > 65536 +#define MAXPACKET PACKETSZ +#else +#define MAXPACKET 65536 +#endif + #ifndef _LIBC #include #else @@ -193,10 +200,10 @@ static const int highestFD = FD_SETSIZE - 1; /* Forward. */ static int send_vc(res_state, const u_char *, int, - u_char *, int, int *, int); + u_char **, int *, int *, int, u_char **); static int send_dg(res_state, const u_char *, int, - u_char *, int, int *, int, - int *, int *); + u_char **, int *, int *, int, + int *, int *, u_char **); #ifdef DEBUG static void Aerror(const res_state, FILE *, const char *, int, struct sockaddr_in); @@ -371,8 +378,8 @@ res_queriesmatch(const u_char *buf1, const u_char *eom1, } int -res_nsend(res_state statp, - const u_char *buf, int buflen, u_char *ans, int anssiz) +__libc_res_nsend(res_state statp, const u_char *buf, int buflen, + u_char *ans, int anssiz, u_char **ansp) { int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; @@ -380,10 +387,22 @@ res_nsend(res_state statp, __set_errno (ESRCH); return (-1); } + if (anssiz < 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; + } + DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY), (stdout, ";; res_send()\n"), buf, buflen); v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ; @@ -578,8 +597,8 @@ res_nsend(res_state statp, if (v_circuit) { /* Use VC; at most one attempt per server. */ try = statp->retry; - n = send_vc(statp, buf, buflen, ans, anssiz, &terrno, - ns); + n = send_vc(statp, buf, buflen, &ans, &anssiz, &terrno, + ns, ansp); if (n < 0) return (-1); if (n == 0) @@ -587,8 +606,8 @@ res_nsend(res_state statp, resplen = n; } else { /* Use datagrams. */ - n = send_dg(statp, buf, buflen, ans, anssiz, &terrno, - ns, &v_circuit, &gotsomewhere); + n = send_dg(statp, buf, buflen, &ans, &anssiz, &terrno, + ns, &v_circuit, &gotsomewhere, ansp); if (n < 0) return (-1); if (n == 0) @@ -667,14 +686,23 @@ res_nsend(res_state statp, return (-1); } +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); +} + /* Private */ static int send_vc(res_state statp, - const u_char *buf, int buflen, u_char *ans, int anssiz, - int *terrno, int ns) + const u_char *buf, int buflen, u_char **ansp, int *anssizp, + int *terrno, int ns, u_char **anscp) { const HEADER *hp = (HEADER *) buf; + u_char *ans = *ansp; + int anssiz = *anssizp; HEADER *anhp = (HEADER *) ans; #ifdef _LIBC struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns]; @@ -782,11 +810,26 @@ send_vc(res_state statp, } resplen = ns_get16(ans); if (resplen > anssiz) { - Dprint(statp->options & RES_DEBUG, - (stdout, ";; response truncated\n") - ); - truncating = 1; - len = anssiz; + if (anscp) { + ans = malloc (MAXPACKET); + if (ans == NULL) { + *terrno = ENOMEM; + res_nclose(statp); + return (0); + } + anssiz = MAXPACKET; + *anssizp = MAXPACKET; + *ansp = ans; + *anscp = ans; + anhp = (HEADER *) ans; + len = resplen; + } else { + Dprint(statp->options & RES_DEBUG, + (stdout, ";; response truncated\n") + ); + truncating = 1; + len = anssiz; + } } else len = resplen; if (len < HFIXEDSZ) { @@ -851,10 +894,12 @@ send_vc(res_state statp, static int send_dg(res_state statp, - const u_char *buf, int buflen, u_char *ans, int anssiz, - int *terrno, int ns, int *v_circuit, int *gotsomewhere) + const u_char *buf, int buflen, u_char **ansp, int *anssizp, + int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp) { const HEADER *hp = (HEADER *) buf; + u_char *ans = *ansp; + int anssiz = *anssizp; HEADER *anhp = (HEADER *) ans; #ifdef _LIBC struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns]; @@ -992,6 +1037,21 @@ send_dg(res_state statp, #else fromlen = sizeof(struct sockaddr_in); #endif + if (anssiz < MAXPACKET + && anscp + && (ioctl (s, FIONREAD, &resplen) < 0 + || anssiz < resplen)) { + ans = malloc (MAXPACKET); + if (ans == NULL) + ans = *ansp; + else { + anssiz = MAXPACKET; + *anssizp = MAXPACKET; + *ansp = ans; + *anscp = ans; + anhp = (HEADER *) ans; + } + } resplen = recvfrom(s, (char*)ans, anssiz,0, (struct sockaddr *)&from, &fromlen); if (resplen <= 0) { -- cgit 1.4.1