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-rw-r--r--src/network/res_init.c2
-rw-r--r--src/network/res_mkquery.c41
-rw-r--r--src/network/res_msend.c184
-rw-r--r--src/network/res_query.c28
-rw-r--r--src/network/res_querydomain.c14
-rw-r--r--src/network/res_send.c12
6 files changed, 263 insertions, 18 deletions
diff --git a/src/network/res_init.c b/src/network/res_init.c
index cbd5b155..5dba9dfc 100644
--- a/src/network/res_init.c
+++ b/src/network/res_init.c
@@ -1,3 +1,5 @@
+#include <resolv.h>
+
int res_init()
{
return 0;
diff --git a/src/network/res_mkquery.c b/src/network/res_mkquery.c
new file mode 100644
index 00000000..f7e4e9c6
--- /dev/null
+++ b/src/network/res_mkquery.c
@@ -0,0 +1,41 @@
+#include <resolv.h>
+#include <string.h>
+#include <time.h>
+#include "libc.h"
+
+int __res_mkquery(int op, const char *dname, int class, int type,
+ const unsigned char *data, int datalen,
+ const unsigned char *newrr, unsigned char *buf, int buflen)
+{
+ int id, i, j;
+ unsigned char q[280];
+ struct timespec ts;
+ size_t l = strnlen(dname, 256);
+
+ if (l-1>=254 || buflen<18+l || op>15u || class>255u || type>255u)
+ return -1;
+
+ /* Construct query template - ID will be filled later */
+ memset(q, 0, 18+l);
+ q[2] = op*8 + 1;
+ q[5] = 1;
+ memcpy((char *)q+13, dname, l);
+ for (i=13; q[i]; i=j+1) {
+ for (j=i; q[j] && q[j] != '.'; j++);
+ if (j-i-1u > 62u) return -1;
+ q[i-1] = j-i;
+ }
+ q[i+1] = type;
+ q[i+3] = class;
+
+ /* Make a reasonably unpredictable id */
+ clock_gettime(CLOCK_REALTIME, &ts);
+ id = ts.tv_nsec + ts.tv_nsec/65536UL & 0xffff;
+ q[0] = id/256;
+ q[1] = id;
+
+ memcpy(buf, q, 18+l);
+ return 18+l;
+}
+
+weak_alias(__res_mkquery, res_mkquery);
diff --git a/src/network/res_msend.c b/src/network/res_msend.c
new file mode 100644
index 00000000..cded5353
--- /dev/null
+++ b/src/network/res_msend.c
@@ -0,0 +1,184 @@
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <stdint.h>
+#include <string.h>
+#include <poll.h>
+#include <time.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+#include "stdio_impl.h"
+#include "syscall.h"
+
+static void cleanup(void *p)
+{
+ __syscall(SYS_close, (intptr_t)p);
+}
+
+static unsigned long mtime()
+{
+ struct timespec ts;
+ clock_gettime(CLOCK_REALTIME, &ts);
+ return (unsigned long)ts.tv_sec * 1000
+ + ts.tv_nsec / 1000000;
+}
+
+int __res_msend(int nqueries, const unsigned char *const *queries,
+ const int *qlens, unsigned char *const *answers, int *alens, int asize)
+{
+ int fd;
+ FILE *f, _f;
+ unsigned char _buf[256];
+ char line[64], *s, *z;
+ int timeout = 5000, attempts = 2, retry_interval;
+ union {
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+ } sa = {0}, ns[3] = {{0}};
+ socklen_t sl = sizeof sa.sin;
+ int nns = 0;
+ int family = AF_INET;
+ int rlen;
+ int next;
+ int i, j;
+ int cs;
+ struct pollfd pfd;
+ unsigned long t0, t1, t2;
+
+ pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
+ /* Get nameservers from resolv.conf, fallback to localhost */
+ f = __fopen_rb_ca("/etc/resolv.conf", &_f, _buf, sizeof _buf);
+ if (f) for (nns=0; nns<3 && fgets(line, sizeof line, f); ) {
+ if (!strncmp(line, "options", 7) && isspace(line[7])) {
+ unsigned long x;
+ char *p, *z;
+ p = strstr(line, "timeout:");
+ if (p && isdigit(p[8])) {
+ p += 8;
+ x = strtoul(p, &z, 10);
+ if (z != p) timeout = x < 30 ? x*1000 : 30000;
+ }
+ p = strstr(line, "attempts:");
+ if (p && isdigit(p[9])) {
+ p += 9;
+ x = strtoul(p, &z, 10);
+ if (z != p) attempts = x < 10 ? x : 10;
+ if (!attempts) attempts = 1;
+ }
+ }
+ if (strncmp(line, "nameserver", 10) || !isspace(line[10]))
+ continue;
+ for (s=line+11; isspace(*s); s++);
+ for (z=s; *z && !isspace(*z); z++);
+ *z=0;
+
+ if (inet_pton(AF_INET, s, &ns[nns].sin.sin_addr)>0) {
+ ns[nns].sin.sin_port = htons(53);
+ ns[nns++].sin.sin_family = AF_INET;
+ } else if (inet_pton(AF_INET6, s, &ns[nns].sin6.sin6_addr)>0) {
+ sl = sizeof sa.sin6;
+ ns[nns].sin6.sin6_port = htons(53);
+ ns[nns++].sin6.sin6_family = family = AF_INET6;
+ }
+ }
+ if (f) __fclose_ca(f);
+ if (!nns) {
+ ns[0].sin.sin_family = AF_INET;
+ ns[0].sin.sin_port = htons(53);
+ ns[0].sin.sin_addr.s_addr = htonl(0x7f000001);
+ nns=1;
+ }
+
+ /* 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) {
+ fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ family = AF_INET;
+ }
+ if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) return -1;
+
+ /* Past this point, there are no errors. Each individual query will
+ * 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);
+ pthread_setcancelstate(cs, 0);
+
+ /* Convert any IPv4 addresses in a mixed environment to v4-mapped */
+ if (family == AF_INET6) {
+ setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &(int){0}, sizeof 0);
+ for (i=0; i<nns; i++) {
+ if (ns[i].sin.sin_family != AF_INET) continue;
+ memcpy(ns[i].sin6.sin6_addr.s6_addr+12,
+ &ns[i].sin.sin_addr, 4);
+ memcpy(ns[i].sin6.sin6_addr.s6_addr,
+ "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
+ ns[i].sin6.sin6_family = AF_INET6;
+ ns[i].sin6.sin6_flowinfo = 0;
+ ns[i].sin6.sin6_scope_id = 0;
+ }
+ }
+
+ memset(alens, 0, sizeof *alens * nqueries);
+
+ pfd.fd = fd;
+ pfd.events = POLLIN;
+ retry_interval = timeout / attempts;
+ t0 = t2 = mtime();
+ t1 = t2 - retry_interval;
+
+ for (; t2-t0 < timeout; t2=mtime()) {
+ if (t2-t1 >= retry_interval) {
+ /* Query all configured namservers in parallel */
+ for (i=0; i<nqueries; i++)
+ if (!alens[i])
+ for (j=0; j<nns; j++)
+ sendto(fd, queries[i],
+ qlens[i], MSG_NOSIGNAL,
+ (void *)&ns[j], sl);
+ t1 = t2;
+ }
+
+ /* Wait for a response, or until time to retry */
+ if (poll(&pfd, 1, t1+retry_interval-t2) <= 0) continue;
+
+ while ((rlen = recvfrom(fd, answers[next], asize, 0,
+ (void *)&sa, (socklen_t[1]){sl})) >= 0) {
+
+ /* Ignore non-identifiable packets (no query id) */
+ if (rlen < 2) continue;
+
+ /* Ignore replies from addresses we didn't send to */
+ for (i=0; i<nns && memcmp(ns+i, &sa, sl); i++);
+ if (i==nns) continue;
+
+ /* Find which query this answer goes with, if any */
+ for (i=next; i<nqueries && (
+ answers[next][0] != queries[i][0] ||
+ answers[next][1] != queries[i][1] ); i++);
+ if (i==nqueries) continue;
+ if (alens[i]) continue;
+
+ /* Store answer in the right slot, or update next
+ * available temp slot if it's already in place. */
+ alens[i] = rlen;
+ if (i == next)
+ for (; next<nqueries && alens[next]; next++);
+ else
+ memcpy(answers[i], answers[next], rlen);
+
+ if (next == nqueries) goto out;
+ }
+ }
+out:
+ pthread_cleanup_pop(1);
+
+ return 0;
+}
diff --git a/src/network/res_query.c b/src/network/res_query.c
index 3847da37..2b4e4bb1 100644
--- a/src/network/res_query.c
+++ b/src/network/res_query.c
@@ -1,25 +1,17 @@
-#define _GNU_SOURCE
#include <resolv.h>
#include <netdb.h>
-#include "__dns.h"
#include "libc.h"
-int res_query(const char *name, int class, int type, unsigned char *dest, int len)
+int __res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
+int __res_send(const unsigned char *, int, unsigned char *, int);
+
+int __res_query(const char *name, int class, int type, unsigned char *dest, int len)
{
- if (class != 1 || len < 512)
- return -1;
- switch(__dns_doqueries(dest, name, &type, 1)) {
- case EAI_NONAME:
- h_errno = HOST_NOT_FOUND;
- return -1;
- case EAI_AGAIN:
- h_errno = TRY_AGAIN;
- return -1;
- case EAI_FAIL:
- h_errno = NO_RECOVERY;
- return -1;
- }
- return 512;
+ unsigned char q[280];
+ int ql = __res_mkquery(0, name, class, type, 0, 0, 0, q, sizeof q);
+ if (ql < 0) return ql;
+ return __res_send(q, ql, dest, len);
}
-weak_alias(res_query, res_search);
+weak_alias(__res_query, res_query);
+weak_alias(__res_query, res_search);
diff --git a/src/network/res_querydomain.c b/src/network/res_querydomain.c
new file mode 100644
index 00000000..c746dbe6
--- /dev/null
+++ b/src/network/res_querydomain.c
@@ -0,0 +1,14 @@
+#include <resolv.h>
+#include <string.h>
+
+int res_querydomain(const char *name, const char *domain, int class, int type, unsigned char *dest, int len)
+{
+ char tmp[256];
+ size_t nl = strnlen(name, 256);
+ size_t dl = strnlen(domain, 256);
+ if (nl+dl+1 > 255) return -1;
+ memcpy(tmp, name, nl);
+ tmp[nl] = '.';
+ memcpy(tmp+nl+1, domain, dl+1);
+ return res_query(tmp, class, type, dest, len);
+}
diff --git a/src/network/res_send.c b/src/network/res_send.c
new file mode 100644
index 00000000..19cfe0f6
--- /dev/null
+++ b/src/network/res_send.c
@@ -0,0 +1,12 @@
+#include <resolv.h>
+#include "libc.h"
+
+int __res_msend(int, const unsigned char *const *, const int *, unsigned char *const *, int *, int);
+
+int __res_send(const unsigned char *msg, int msglen, unsigned char *answer, int anslen)
+{
+ int r = __res_msend(1, &msg, &msglen, &answer, &anslen, anslen);
+ return r<0 ? r : anslen;
+}
+
+weak_alias(__res_send, res_send);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-30 22:34:42 +0000