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Diffstat (limited to 'resolv/res_send.c')
-rw-r--r--resolv/res_send.c323
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.
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-27 05:24:37 +0000