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-rw-r--r--src/network/gai_strerror.c2
-rw-r--r--src/network/getaddrinfo.c5
-rw-r--r--src/network/gethostbyaddr.c2
-rw-r--r--src/network/gethostbyaddr_r.c5
-rw-r--r--src/network/gethostbyname2.c2
-rw-r--r--src/network/gethostbyname2_r.c6
-rw-r--r--src/network/lookup_ipliteral.c4
-rw-r--r--src/network/lookup_name.c44
-rw-r--r--src/network/res_mkquery.c1
-rw-r--r--src/network/res_msend.c155
-rw-r--r--src/network/res_send.c10
11 files changed, 197 insertions, 39 deletions
diff --git a/src/network/gai_strerror.c b/src/network/gai_strerror.c
index 9596580e..56b71503 100644
--- a/src/network/gai_strerror.c
+++ b/src/network/gai_strerror.c
@@ -6,7 +6,7 @@ static const char msgs[] =
"Name does not resolve\0"
"Try again\0"
"Non-recoverable error\0"
- "Unknown error\0"
+ "Name has no usable address\0"
"Unrecognized address family or invalid length\0"
"Unrecognized socket type\0"
"Unrecognized service\0"
diff --git a/src/network/getaddrinfo.c b/src/network/getaddrinfo.c
index 9df045f6..64ad259a 100644
--- a/src/network/getaddrinfo.c
+++ b/src/network/getaddrinfo.c
@@ -16,6 +16,7 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru
char canon[256], *outcanon;
int nservs, naddrs, nais, canon_len, i, j, k;
int family = AF_UNSPEC, flags = 0, proto = 0, socktype = 0;
+ int no_family = 0;
struct aibuf *out;
if (!host && !serv) return EAI_NONAME;
@@ -82,7 +83,7 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru
default:
return EAI_SYSTEM;
}
- if (family == tf[i]) return EAI_NONAME;
+ if (family == tf[i]) no_family = 1;
family = tf[1-i];
}
}
@@ -93,6 +94,8 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru
naddrs = __lookup_name(addrs, canon, host, family, flags);
if (naddrs < 0) return naddrs;
+ if (no_family) return EAI_NODATA;
+
nais = nservs * naddrs;
canon_len = strlen(canon);
out = calloc(1, nais * sizeof(*out) + canon_len + 1);
diff --git a/src/network/gethostbyaddr.c b/src/network/gethostbyaddr.c
index 598e2241..c3cacaac 100644
--- a/src/network/gethostbyaddr.c
+++ b/src/network/gethostbyaddr.c
@@ -20,5 +20,5 @@ struct hostent *gethostbyaddr(const void *a, socklen_t l, int af)
err = gethostbyaddr_r(a, l, af, h,
(void *)(h+1), size-sizeof *h, &res, &h_errno);
} while (err == ERANGE);
- return err ? 0 : h;
+ return res;
}
diff --git a/src/network/gethostbyaddr_r.c b/src/network/gethostbyaddr_r.c
index 0f1e61aa..ceaf3935 100644
--- a/src/network/gethostbyaddr_r.c
+++ b/src/network/gethostbyaddr_r.c
@@ -54,10 +54,11 @@ int gethostbyaddr_r(const void *a, socklen_t l, int af,
case EAI_OVERFLOW:
return ERANGE;
default:
- case EAI_MEMORY:
- case EAI_SYSTEM:
case EAI_FAIL:
*err = NO_RECOVERY;
+ return EBADMSG;
+ case EAI_SYSTEM:
+ *err = NO_RECOVERY;
return errno;
case 0:
break;
diff --git a/src/network/gethostbyname2.c b/src/network/gethostbyname2.c
index dc9d6621..bd0da7f8 100644
--- a/src/network/gethostbyname2.c
+++ b/src/network/gethostbyname2.c
@@ -21,5 +21,5 @@ struct hostent *gethostbyname2(const char *name, int af)
err = gethostbyname2_r(name, af, h,
(void *)(h+1), size-sizeof *h, &res, &h_errno);
} while (err == ERANGE);
- return err ? 0 : h;
+ return res;
}
diff --git a/src/network/gethostbyname2_r.c b/src/network/gethostbyname2_r.c
index fc894877..a5eb67fe 100644
--- a/src/network/gethostbyname2_r.c
+++ b/src/network/gethostbyname2_r.c
@@ -22,7 +22,10 @@ int gethostbyname2_r(const char *name, int af,
if (cnt<0) switch (cnt) {
case EAI_NONAME:
*err = HOST_NOT_FOUND;
- return ENOENT;
+ return 0;
+ case EAI_NODATA:
+ *err = NO_DATA;
+ return 0;
case EAI_AGAIN:
*err = TRY_AGAIN;
return EAGAIN;
@@ -30,7 +33,6 @@ int gethostbyname2_r(const char *name, int af,
case EAI_FAIL:
*err = NO_RECOVERY;
return EBADMSG;
- case EAI_MEMORY:
case EAI_SYSTEM:
*err = NO_RECOVERY;
return errno;
diff --git a/src/network/lookup_ipliteral.c b/src/network/lookup_ipliteral.c
index 2fddab73..1e766206 100644
--- a/src/network/lookup_ipliteral.c
+++ b/src/network/lookup_ipliteral.c
@@ -15,7 +15,7 @@ int __lookup_ipliteral(struct address buf[static 1], const char *name, int famil
struct in6_addr a6;
if (__inet_aton(name, &a4) > 0) {
if (family == AF_INET6) /* wrong family */
- return EAI_NONAME;
+ return EAI_NODATA;
memcpy(&buf[0].addr, &a4, sizeof a4);
buf[0].family = AF_INET;
buf[0].scopeid = 0;
@@ -34,7 +34,7 @@ int __lookup_ipliteral(struct address buf[static 1], const char *name, int famil
if (inet_pton(AF_INET6, name, &a6) <= 0)
return 0;
if (family == AF_INET) /* wrong family */
- return EAI_NONAME;
+ return EAI_NODATA;
memcpy(&buf[0].addr, &a6, sizeof a6);
buf[0].family = AF_INET6;
diff --git a/src/network/lookup_name.c b/src/network/lookup_name.c
index b5232ce8..5f6867cb 100644
--- a/src/network/lookup_name.c
+++ b/src/network/lookup_name.c
@@ -79,7 +79,7 @@ static int name_from_hosts(struct address buf[static MAXADDRS], char canon[stati
case 0:
continue;
default:
- badfam = EAI_NONAME;
+ badfam = EAI_NODATA;
break;
}
@@ -102,45 +102,50 @@ struct dpc_ctx {
struct address *addrs;
char *canon;
int cnt;
+ int rrtype;
};
#define RR_A 1
#define RR_CNAME 5
#define RR_AAAA 28
+#define ABUF_SIZE 768
+
static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet)
{
char tmp[256];
+ int family;
struct dpc_ctx *ctx = c;
- if (ctx->cnt >= MAXADDRS) return -1;
+ if (rr == RR_CNAME) {
+ if (__dn_expand(packet, (const unsigned char *)packet + ABUF_SIZE,
+ data, tmp, sizeof tmp) > 0 && is_valid_hostname(tmp))
+ strcpy(ctx->canon, tmp);
+ return 0;
+ }
+ if (ctx->cnt >= MAXADDRS) return 0;
+ if (rr != ctx->rrtype) return 0;
switch (rr) {
case RR_A:
if (len != 4) return -1;
- ctx->addrs[ctx->cnt].family = AF_INET;
- ctx->addrs[ctx->cnt].scopeid = 0;
- memcpy(ctx->addrs[ctx->cnt++].addr, data, 4);
+ family = AF_INET;
break;
case RR_AAAA:
if (len != 16) return -1;
- ctx->addrs[ctx->cnt].family = AF_INET6;
- ctx->addrs[ctx->cnt].scopeid = 0;
- memcpy(ctx->addrs[ctx->cnt++].addr, data, 16);
- break;
- case RR_CNAME:
- if (__dn_expand(packet, (const unsigned char *)packet + 512,
- data, tmp, sizeof tmp) > 0 && is_valid_hostname(tmp))
- strcpy(ctx->canon, tmp);
+ family = AF_INET6;
break;
}
+ ctx->addrs[ctx->cnt].family = family;
+ ctx->addrs[ctx->cnt].scopeid = 0;
+ memcpy(ctx->addrs[ctx->cnt++].addr, data, len);
return 0;
}
static int name_from_dns(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family, const struct resolvconf *conf)
{
- unsigned char qbuf[2][280], abuf[2][512];
+ unsigned char qbuf[2][280], abuf[2][ABUF_SIZE];
const unsigned char *qp[2] = { qbuf[0], qbuf[1] };
unsigned char *ap[2] = { abuf[0], abuf[1] };
- int qlens[2], alens[2];
+ int qlens[2], alens[2], qtypes[2];
int i, nq = 0;
struct dpc_ctx ctx = { .addrs = buf, .canon = canon };
static const struct { int af; int rr; } afrr[2] = {
@@ -153,7 +158,8 @@ static int name_from_dns(struct address buf[static MAXADDRS], char canon[static
qlens[nq] = __res_mkquery(0, name, 1, afrr[i].rr,
0, 0, 0, qbuf[nq], sizeof *qbuf);
if (qlens[nq] == -1)
- return EAI_NONAME;
+ return 0;
+ qtypes[nq] = afrr[i].rr;
qbuf[nq][3] = 0; /* don't need AD flag */
/* Ensure query IDs are distinct. */
if (nq && qbuf[nq][0] == qbuf[0][0])
@@ -171,11 +177,13 @@ static int name_from_dns(struct address buf[static MAXADDRS], char canon[static
if ((abuf[i][3] & 15) != 0) return EAI_FAIL;
}
- for (i=0; i<nq; i++)
+ for (i=nq-1; i>=0; i--) {
+ ctx.rrtype = qtypes[i];
__dns_parse(abuf[i], alens[i], dns_parse_callback, &ctx);
+ }
if (ctx.cnt) return ctx.cnt;
- return EAI_NONAME;
+ return EAI_NODATA;
}
static int name_from_dns_search(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family)
diff --git a/src/network/res_mkquery.c b/src/network/res_mkquery.c
index 33f50cb9..614bf786 100644
--- a/src/network/res_mkquery.c
+++ b/src/network/res_mkquery.c
@@ -13,6 +13,7 @@ int __res_mkquery(int op, const char *dname, int class, int type,
int n;
if (l && dname[l-1]=='.') l--;
+ if (l && dname[l-1]=='.') return -1;
n = 17+l+!!l;
if (l>253 || buflen<n || op>15u || class>255u || type>255u)
return -1;
diff --git a/src/network/res_msend.c b/src/network/res_msend.c
index 3e018009..11c6aa0e 100644
--- a/src/network/res_msend.c
+++ b/src/network/res_msend.c
@@ -1,5 +1,6 @@
#include <sys/socket.h>
#include <netinet/in.h>
+#include <netinet/tcp.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdint.h>
@@ -16,7 +17,9 @@
static void cleanup(void *p)
{
- __syscall(SYS_close, (intptr_t)p);
+ struct pollfd *pfd = p;
+ for (int i=0; pfd[i].fd >= -1; i++)
+ if (pfd[i].fd >= 0) __syscall(SYS_close, pfd[i].fd);
}
static unsigned long mtime()
@@ -27,6 +30,51 @@ static unsigned long mtime()
+ ts.tv_nsec / 1000000;
}
+static int start_tcp(struct pollfd *pfd, int family, const void *sa, socklen_t sl, const unsigned char *q, int ql)
+{
+ struct msghdr mh = {
+ .msg_name = (void *)sa,
+ .msg_namelen = sl,
+ .msg_iovlen = 2,
+ .msg_iov = (struct iovec [2]){
+ { .iov_base = (uint8_t[]){ ql>>8, ql }, .iov_len = 2 },
+ { .iov_base = (void *)q, .iov_len = ql } }
+ };
+ int r;
+ int fd = socket(family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ pfd->fd = fd;
+ pfd->events = POLLOUT;
+ if (!setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN_CONNECT,
+ &(int){1}, sizeof(int))) {
+ r = sendmsg(fd, &mh, MSG_FASTOPEN|MSG_NOSIGNAL);
+ if (r == ql+2) pfd->events = POLLIN;
+ if (r >= 0) return r;
+ if (errno == EINPROGRESS) return 0;
+ }
+ r = connect(fd, sa, sl);
+ if (!r || errno == EINPROGRESS) return 0;
+ close(fd);
+ pfd->fd = -1;
+ return -1;
+}
+
+static void step_mh(struct msghdr *mh, size_t n)
+{
+ /* Adjust iovec in msghdr to skip first n bytes. */
+ while (mh->msg_iovlen && n >= mh->msg_iov->iov_len) {
+ n -= mh->msg_iov->iov_len;
+ mh->msg_iov++;
+ mh->msg_iovlen--;
+ }
+ if (!mh->msg_iovlen) return;
+ mh->msg_iov->iov_base = (char *)mh->msg_iov->iov_base + n;
+ mh->msg_iov->iov_len -= n;
+}
+
+/* Internal contract for __res_msend[_rc]: asize must be >=512, nqueries
+ * must be sufficiently small to be safe as VLA size. In practice it's
+ * either 1 or 2, anyway. */
+
int __res_msend_rc(int nqueries, const unsigned char *const *queries,
const int *qlens, unsigned char *const *answers, int *alens, int asize,
const struct resolvconf *conf)
@@ -44,7 +92,10 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries,
int next;
int i, j;
int cs;
- struct pollfd pfd;
+ struct pollfd pfd[nqueries+2];
+ int qpos[nqueries], apos[nqueries];
+ unsigned char alen_buf[nqueries][2];
+ int r;
unsigned long t0, t1, t2;
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
@@ -68,14 +119,20 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries,
}
/* Get local address and open/bind a socket */
- sa.sin.sin_family = family;
fd = socket(family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
/* Handle case where system lacks IPv6 support */
if (fd < 0 && family == AF_INET6 && errno == EAFNOSUPPORT) {
+ for (i=0; i<nns && conf->ns[nns].family == AF_INET6; i++);
+ if (i==nns) {
+ pthread_setcancelstate(cs, 0);
+ return -1;
+ }
fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
family = AF_INET;
+ sl = sizeof sa.sin;
}
+ sa.sin.sin_family = family;
if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) {
if (fd >= 0) close(fd);
pthread_setcancelstate(cs, 0);
@@ -86,7 +143,12 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries,
* yield either no reply (indicated by zero length) or an answer
* packet which is up to the caller to interpret. */
- pthread_cleanup_push(cleanup, (void *)(intptr_t)fd);
+ for (i=0; i<nqueries; i++) pfd[i].fd = -1;
+ pfd[nqueries].fd = fd;
+ pfd[nqueries].events = POLLIN;
+ pfd[nqueries+1].fd = -2;
+
+ pthread_cleanup_push(cleanup, pfd);
pthread_setcancelstate(cs, 0);
/* Convert any IPv4 addresses in a mixed environment to v4-mapped */
@@ -106,14 +168,17 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries,
memset(alens, 0, sizeof *alens * nqueries);
- pfd.fd = fd;
- pfd.events = POLLIN;
retry_interval = timeout / attempts;
next = 0;
t0 = t2 = mtime();
t1 = t2 - retry_interval;
for (; t2-t0 < timeout; t2=mtime()) {
+ /* This is the loop exit condition: that all queries
+ * have an accepted answer. */
+ for (i=0; i<nqueries && alens[i]>0; i++);
+ if (i==nqueries) break;
+
if (t2-t1 >= retry_interval) {
/* Query all configured namservers in parallel */
for (i=0; i<nqueries; i++)
@@ -127,10 +192,20 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries,
}
/* Wait for a response, or until time to retry */
- if (poll(&pfd, 1, t1+retry_interval-t2) <= 0) continue;
+ if (poll(pfd, nqueries+1, t1+retry_interval-t2) <= 0) continue;
- while ((rlen = recvfrom(fd, answers[next], asize, 0,
- (void *)&sa, (socklen_t[1]){sl})) >= 0) {
+ while (next < nqueries) {
+ struct msghdr mh = {
+ .msg_name = (void *)&sa,
+ .msg_namelen = sl,
+ .msg_iovlen = 1,
+ .msg_iov = (struct iovec []){
+ { .iov_base = (void *)answers[next],
+ .iov_len = asize }
+ }
+ };
+ rlen = recvmsg(fd, &mh, 0);
+ if (rlen < 0) break;
/* Ignore non-identifiable packets */
if (rlen < 4) continue;
@@ -170,12 +245,72 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries,
else
memcpy(answers[i], answers[next], rlen);
- if (next == nqueries) goto out;
+ /* Ignore further UDP if all slots full or TCP-mode */
+ if (next == nqueries) pfd[nqueries].events = 0;
+
+ /* If answer is truncated (TC bit), fallback to TCP */
+ if ((answers[i][2] & 2) || (mh.msg_flags & MSG_TRUNC)) {
+ alens[i] = -1;
+ pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0);
+ r = start_tcp(pfd+i, family, ns+j, sl, queries[i], qlens[i]);
+ pthread_setcancelstate(cs, 0);
+ if (r >= 0) {
+ qpos[i] = r;
+ apos[i] = 0;
+ }
+ continue;
+ }
+ }
+
+ for (i=0; i<nqueries; i++) if (pfd[i].revents & POLLOUT) {
+ struct msghdr mh = {
+ .msg_iovlen = 2,
+ .msg_iov = (struct iovec [2]){
+ { .iov_base = (uint8_t[]){ qlens[i]>>8, qlens[i] }, .iov_len = 2 },
+ { .iov_base = (void *)queries[i], .iov_len = qlens[i] } }
+ };
+ step_mh(&mh, qpos[i]);
+ r = sendmsg(pfd[i].fd, &mh, MSG_NOSIGNAL);
+ if (r < 0) goto out;
+ qpos[i] += r;
+ if (qpos[i] == qlens[i]+2)
+ pfd[i].events = POLLIN;
+ }
+
+ for (i=0; i<nqueries; i++) if (pfd[i].revents & POLLIN) {
+ struct msghdr mh = {
+ .msg_iovlen = 2,
+ .msg_iov = (struct iovec [2]){
+ { .iov_base = alen_buf[i], .iov_len = 2 },
+ { .iov_base = answers[i], .iov_len = asize } }
+ };
+ step_mh(&mh, apos[i]);
+ r = recvmsg(pfd[i].fd, &mh, 0);
+ if (r < 0) goto out;
+ apos[i] += r;
+ if (apos[i] < 2) continue;
+ int alen = alen_buf[i][0]*256 + alen_buf[i][1];
+ if (alen < 13) goto out;
+ if (apos[i] < alen+2 && apos[i] < asize+2)
+ continue;
+ int rcode = answers[i][3] & 15;
+ if (rcode != 0 && rcode != 3)
+ goto out;
+
+ /* Storing the length here commits the accepted answer.
+ * Immediately close TCP socket so as not to consume
+ * resources we no longer need. */
+ alens[i] = alen;
+ __syscall(SYS_close, pfd[i].fd);
+ pfd[i].fd = -1;
}
}
out:
pthread_cleanup_pop(1);
+ /* Disregard any incomplete TCP results */
+ for (i=0; i<nqueries; i++) if (alens[i]<0) alens[i] = 0;
+
return 0;
}
diff --git a/src/network/res_send.c b/src/network/res_send.c
index ee4abf1f..9593164d 100644
--- a/src/network/res_send.c
+++ b/src/network/res_send.c
@@ -1,8 +1,16 @@
#include <resolv.h>
+#include <string.h>
int __res_send(const unsigned char *msg, int msglen, unsigned char *answer, int anslen)
{
- int r = __res_msend(1, &msg, &msglen, &answer, &anslen, anslen);
+ int r;
+ if (anslen < 512) {
+ unsigned char buf[512];
+ r = __res_send(msg, msglen, buf, sizeof buf);
+ if (r >= 0) memcpy(answer, buf, r < anslen ? r : anslen);
+ return r;
+ }
+ r = __res_msend(1, &msg, &msglen, &answer, &anslen, anslen);
return r<0 || !anslen ? -1 : anslen;
}