[git commit] nslookup: add openwrt / lede version
Denys Vlasenko
vda.linux at googlemail.com
Sat Apr 14 12:05:45 UTC 2018
commit: https://git.busybox.net/busybox/commit/?id=0dd3be8c0933d5649152b6019b975876e804e22a
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
Needs work on size reduction
function old new delta
nslookup_main 114 2363 +2249
parse_reply - 1022 +1022
add_ns - 663 +663
ns_parserr - 486 +486
ns_initparse - 184 +184
ns_skiprr - 117 +117
add_query - 95 +95
qtypes - 80 +80
rcodes - 68 +68
dn_skipname - 58 +58
ns_name_uncompress - 56 +56
ns_get16 - 13 +13
v4_mapped - 12 +12
ns_get32 - 9 +9
res_init 3 - -3
__res_state 6 - -6
xmalloc_sockaddr2hostonly_noport 10 - -10
gai_strerror 47 - -47
set_default_dns 95 - -95
print_host 199 - -199
static.res 512 - -512
------------------------------------------------------------------------------
(add/remove: 15/10 grow/shrink: 1/0 up/down: 5112/-872) Total: 4240 bytes
text data bss dec hex filename
921944 555 6252 928751 e2bef busybox_old
927375 555 5740 933670 e3f26 busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
networking/nslookup.c | 919 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 908 insertions(+), 11 deletions(-)
diff --git a/networking/nslookup.c b/networking/nslookup.c
index 45c218e6c..6f8f02fc1 100644
--- a/networking/nslookup.c
+++ b/networking/nslookup.c
@@ -1,20 +1,20 @@
/* vi: set sw=4 ts=4: */
-/*
- * Mini nslookup implementation for busybox
- *
- * Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
- * Copyright (C) 1999,2000,2001 by John Beppu <beppu at codepoet.org>
- *
- * Correct default name server display and explicit name server option
- * added by Ben Zeckel <bzeckel at hmc.edu> June 2001
- *
- * Licensed under GPLv2 or later, see file LICENSE in this source tree.
- */
+
//config:config NSLOOKUP
//config: bool "nslookup (4.5 kb)"
//config: default y
//config: help
//config: nslookup is a tool to query Internet name servers.
+//config:
+//config:config NSLOOKUP_BIG
+//config: bool "Use internal resolver code instead of libc"
+//config: depends on NSLOOKUP
+//config: default y
+//config:
+//config:config FEATURE_NSLOOKUP_LONG_OPTIONS
+//config: bool "Enable long options"
+//config: default y
+//config: depends on NSLOOKUP_BIG && LONG_OPTS
//applet:IF_NSLOOKUP(APPLET(nslookup, BB_DIR_USR_BIN, BB_SUID_DROP))
@@ -35,7 +35,26 @@
//usage: "Address: 127.0.0.1\n"
#include <resolv.h>
+#include <net/if.h> /* for IFNAMSIZ */
+//#include <arpa/inet.h>
+//#include <netdb.h>
#include "libbb.h"
+#include "common_bufsiz.h"
+
+
+#if !ENABLE_NSLOOKUP_BIG
+
+/*
+ * Mini nslookup implementation for busybox
+ *
+ * Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
+ * Copyright (C) 1999,2000,2001 by John Beppu <beppu at codepoet.org>
+ *
+ * Correct default name server display and explicit name server option
+ * added by Ben Zeckel <bzeckel at hmc.edu> June 2001
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
/*
* I'm only implementing non-interactive mode;
@@ -207,3 +226,881 @@ int nslookup_main(int argc, char **argv)
return print_host(argv[1], "Name:");
}
+
+
+#else /****** A version from LEDE / OpenWRT ******/
+
+/*
+ * musl compatible nslookup
+ *
+ * Copyright (C) 2017 Jo-Philipp Wich <jo at mein.io>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#if 0
+# define dbg(...) fprintf(stderr, __VA_ARGS__)
+#else
+# define dbg(...) ((void)0)
+#endif
+
+struct ns {
+ const char *name;
+ len_and_sockaddr addr;
+ int failures;
+ int replies;
+};
+
+struct query {
+ const char *name;
+ size_t qlen, rlen;
+ unsigned char query[512], reply[512];
+ unsigned long latency;
+ int rcode, n_ns;
+};
+
+static const struct {
+ int type;
+ const char *name;
+} qtypes[] = {
+ { ns_t_soa, "SOA" },
+ { ns_t_ns, "NS" },
+ { ns_t_a, "A" },
+#if ENABLE_FEATURE_IPV6
+ { ns_t_aaaa, "AAAA" },
+#endif
+ { ns_t_cname, "CNAME" },
+ { ns_t_mx, "MX" },
+ { ns_t_txt, "TXT" },
+ { ns_t_ptr, "PTR" },
+ { ns_t_any, "ANY" },
+ { }
+};
+
+static const char *const rcodes[] = {
+ "NOERROR",
+ "FORMERR",
+ "SERVFAIL",
+ "NXDOMAIN",
+ "NOTIMP",
+ "REFUSED",
+ "YXDOMAIN",
+ "YXRRSET",
+ "NXRRSET",
+ "NOTAUTH",
+ "NOTZONE",
+ "RESERVED11",
+ "RESERVED12",
+ "RESERVED13",
+ "RESERVED14",
+ "RESERVED15",
+ "BADVERS"
+};
+
+#if ENABLE_FEATURE_IPV6
+static const char v4_mapped[] = { 0,0,0,0,0,0,0,0,0,0,0xff,0xff };
+#endif
+
+struct globals {
+ unsigned default_port;
+ unsigned default_retry;
+ unsigned default_timeout;
+} FIX_ALIASING;
+#define G (*(struct globals*)bb_common_bufsiz1)
+#define INIT_G() do { \
+ setup_common_bufsiz(); \
+ G.default_port = 53; \
+ G.default_retry = 2; \
+ G.default_timeout = 5; \
+} while (0)
+
+static int
+parse_reply(const unsigned char *msg, size_t len, int *bb_style_counter)
+{
+ ns_msg handle;
+ ns_rr rr;
+ int i, n, rdlen;
+ const char *format = NULL;
+ char astr[INET6_ADDRSTRLEN], dname[MAXDNAME];
+ const unsigned char *cp;
+
+ if (ns_initparse(msg, len, &handle) != 0) {
+ //fprintf(stderr, "Unable to parse reply: %s\n", strerror(errno));
+ return -1;
+ }
+
+ for (i = 0; i < ns_msg_count(handle, ns_s_an); i++) {
+ if (ns_parserr(&handle, ns_s_an, i, &rr) != 0) {
+ //fprintf(stderr, "Unable to parse resource record: %s\n", strerror(errno));
+ return -1;
+ }
+
+ if (bb_style_counter && *bb_style_counter == 1)
+ printf("Name: %s\n", ns_rr_name(rr));
+
+ rdlen = ns_rr_rdlen(rr);
+
+ switch (ns_rr_type(rr))
+ {
+ case ns_t_a:
+ if (rdlen != 4) {
+ //fprintf(stderr, "Unexpected A record length\n");
+ return -1;
+ }
+ inet_ntop(AF_INET, ns_rr_rdata(rr), astr, sizeof(astr));
+ if (bb_style_counter)
+ printf("Address %d: %s\n", (*bb_style_counter)++, astr);
+ else
+ printf("Name:\t%s\nAddress: %s\n", ns_rr_name(rr), astr);
+ break;
+
+#if ENABLE_FEATURE_IPV6
+ case ns_t_aaaa:
+ if (rdlen != 16) {
+ //fprintf(stderr, "Unexpected AAAA record length\n");
+ return -1;
+ }
+ inet_ntop(AF_INET6, ns_rr_rdata(rr), astr, sizeof(astr));
+ if (bb_style_counter)
+ printf("Address %d: %s\n", (*bb_style_counter)++, astr);
+ else
+ printf("%s\thas AAAA address %s\n", ns_rr_name(rr), astr);
+ break;
+#endif
+
+ case ns_t_ns:
+ if (!format)
+ format = "%s\tnameserver = %s\n";
+ /* fall through */
+
+ case ns_t_cname:
+ if (!format)
+ format = "%s\tcanonical name = %s\n";
+ /* fall through */
+
+ case ns_t_ptr:
+ if (!format)
+ format = "%s\tname = %s\n";
+ if (ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
+ ns_rr_rdata(rr), dname, sizeof(dname)) < 0) {
+ //fprintf(stderr, "Unable to uncompress domain: %s\n", strerror(errno));
+ return -1;
+ }
+ printf(format, ns_rr_name(rr), dname);
+ break;
+
+ case ns_t_mx:
+ if (rdlen < 2) {
+ fprintf(stderr, "MX record too short\n");
+ return -1;
+ }
+ n = ns_get16(ns_rr_rdata(rr));
+ if (ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
+ ns_rr_rdata(rr) + 2, dname, sizeof(dname)) < 0) {
+ //fprintf(stderr, "Cannot uncompress MX domain: %s\n", strerror(errno));
+ return -1;
+ }
+ printf("%s\tmail exchanger = %d %s\n", ns_rr_name(rr), n, dname);
+ break;
+
+ case ns_t_txt:
+ if (rdlen < 1) {
+ //fprintf(stderr, "TXT record too short\n");
+ return -1;
+ }
+ n = *(unsigned char *)ns_rr_rdata(rr);
+ if (n > 0) {
+ memset(dname, 0, sizeof(dname));
+ memcpy(dname, ns_rr_rdata(rr) + 1, n);
+ printf("%s\ttext = \"%s\"\n", ns_rr_name(rr), dname);
+ }
+ break;
+
+ case ns_t_soa:
+ if (rdlen < 20) {
+ //fprintf(stderr, "SOA record too short\n");
+ return -1;
+ }
+
+ printf("%s\n", ns_rr_name(rr));
+
+ cp = ns_rr_rdata(rr);
+ n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
+ cp, dname, sizeof(dname));
+
+ if (n < 0) {
+ //fprintf(stderr, "Unable to uncompress domain: %s\n", strerror(errno));
+ return -1;
+ }
+
+ printf("\torigin = %s\n", dname);
+ cp += n;
+
+ n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
+ cp, dname, sizeof(dname));
+
+ if (n < 0) {
+ //fprintf(stderr, "Unable to uncompress domain: %s\n", strerror(errno));
+ return -1;
+ }
+
+ printf("\tmail addr = %s\n", dname);
+ cp += n;
+
+ printf("\tserial = %lu\n", ns_get32(cp));
+ cp += 4;
+
+ printf("\trefresh = %lu\n", ns_get32(cp));
+ cp += 4;
+
+ printf("\tretry = %lu\n", ns_get32(cp));
+ cp += 4;
+
+ printf("\texpire = %lu\n", ns_get32(cp));
+ cp += 4;
+
+ printf("\tminimum = %lu\n", ns_get32(cp));
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ return i;
+}
+
+static int parse_nsaddr(const char *addrstr, len_and_sockaddr *lsa)
+{
+ char *hash;
+ unsigned port = G.default_port;
+ IF_FEATURE_IPV6(unsigned scope;)
+
+ dbg("%s: addrstr:'%s'\n", __func__, addrstr);
+
+ hash = strchr(addrstr, '#');
+
+ if (hash) {
+ *hash++ = '\0';
+ port = bb_strtou(hash, NULL, 10);
+ if (errno || port > 65535) {
+ errno = EINVAL;
+ return -1;
+ }
+ }
+
+#if ENABLE_FEATURE_IPV6
+ scope = 0;
+ hash = strchr(addrstr, '%');
+ if (hash) {
+ char ifname[IFNAMSIZ];
+ int i;
+
+ hash++;
+ for (i = 0; hash[i] != '\0' && hash[i] != '#'; i++) {
+ if (i >= IFNAMSIZ) {
+ errno = ENODEV;
+ return -1;
+ }
+ ifname[i] = hash[i];
+ }
+ ifname[i] = '\0';
+
+ scope = if_nametoindex(ifname);
+ if (scope == 0) {
+ errno = ENODEV;
+ return -1;
+ }
+ }
+
+ if (inet_pton(AF_INET6, addrstr, &lsa->u.sin6.sin6_addr)) {
+ lsa->u.sin6.sin6_family = AF_INET6;
+ lsa->u.sin6.sin6_port = htons(port);
+ lsa->u.sin6.sin6_scope_id = scope;
+ lsa->len = sizeof(lsa->u.sin6);
+ return 0;
+ }
+#endif
+
+ if (inet_pton(AF_INET, addrstr, &lsa->u.sin.sin_addr)) {
+ lsa->u.sin.sin_family = AF_INET;
+ lsa->u.sin.sin_port = htons(port);
+ lsa->len = sizeof(lsa->u.sin);
+ return 0;
+ }
+
+ errno = EINVAL;
+ return -1;
+}
+
+static char *make_ptr(char resbuf[80], const char *addrstr)
+{
+ unsigned char addr[16];
+ int i;
+
+#if ENABLE_FEATURE_IPV6
+ if (inet_pton(AF_INET6, addrstr, addr)) {
+ if (memcmp(addr, v4_mapped, 12) != 0) {
+ char *ptr = resbuf;
+ for (i = 0; i < 16; i++) {
+ *ptr++ = 0x20 | bb_hexdigits_upcase[(unsigned char)addr[15 - i] & 0xf];
+ *ptr++ = '.';
+ *ptr++ = 0x20 | bb_hexdigits_upcase[(unsigned char)addr[15 - i] >> 4];
+ *ptr++ = '.';
+ }
+ strcpy(ptr, "ip6.arpa");
+ }
+ else {
+ sprintf(resbuf, "%u.%u.%u.%u.in-addr.arpa",
+ addr[15], addr[14], addr[13], addr[12]);
+ }
+ return resbuf;
+ }
+#endif
+
+ if (inet_pton(AF_INET, addrstr, addr)) {
+ sprintf(resbuf, "%u.%u.%u.%u.in-addr.arpa",
+ addr[3], addr[2], addr[1], addr[0]);
+ return resbuf;
+ }
+
+ return NULL;
+}
+
+#if ENABLE_FEATURE_IPV6
+static void to_v4_mapped(len_and_sockaddr *a)
+{
+ if (a->u.sa.sa_family != AF_INET)
+ return;
+
+ /* Order is important */
+//FIXME: port?
+ memcpy(a->u.sin6.sin6_addr.s6_addr + 12, &a->u.sin.sin_addr, 4);
+ memcpy(a->u.sin6.sin6_addr.s6_addr, v4_mapped, 12);
+
+ a->u.sin6.sin6_family = AF_INET6;
+ a->u.sin6.sin6_flowinfo = 0;
+ a->u.sin6.sin6_scope_id = 0;
+ a->len = sizeof(a->u.sin6);
+}
+#endif
+
+/*
+ * Function logic borrowed & modified from musl libc, res_msend.c
+ */
+static int send_queries(struct ns *ns, int n_ns, struct query *queries, int n_queries)
+{
+ int fd;
+ int timeout = G.default_timeout * 1000, retry_interval, servfail_retry = 0;
+ len_and_sockaddr from = { };
+ int recvlen = 0;
+ int n_replies = 0;
+ struct pollfd pfd;
+ unsigned long t0, t1, t2;
+ int nn, qn, next_query = 0;
+
+ from.u.sa.sa_family = AF_INET;
+ from.len = sizeof(from.u.sin);
+#if ENABLE_FEATURE_IPV6
+ for (nn = 0; nn < n_ns; nn++) {
+ if (ns[nn].addr.u.sa.sa_family == AF_INET6) {
+ from.u.sa.sa_family = AF_INET6;
+ from.len = sizeof(from.u.sin6);
+ break;
+ }
+ }
+#endif
+
+ /* Get local address and open/bind a socket */
+#if ENABLE_FEATURE_IPV6
+ fd = socket(from.u.sa.sa_family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ /* Handle case where system lacks IPv6 support */
+ if (fd < 0) {
+ if (from.u.sa.sa_family != AF_INET6 || errno != EAFNOSUPPORT)
+ bb_perror_msg_and_die("socket");
+ fd = xsocket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ from.u.sa.sa_family = AF_INET;
+ }
+#else
+ fd = xsocket(from.u.sa.sa_family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+#endif
+ xbind(fd, &from.u.sa, from.len);
+
+#if ENABLE_FEATURE_IPV6
+ /* Convert any IPv4 addresses in a mixed environment to v4-mapped */
+ if (from.u.sa.sa_family == AF_INET6) {
+ setsockopt_1(fd, IPPROTO_IPV6, IPV6_V6ONLY);
+ for (nn = 0; nn < n_ns; nn++)
+ to_v4_mapped(&ns[nn].addr);
+ }
+#endif
+
+ pfd.fd = fd;
+ pfd.events = POLLIN;
+ retry_interval = timeout / G.default_retry;
+ t0 = t2 = monotonic_ms();
+ t1 = t2 - retry_interval;
+
+ for (; t2 - t0 < timeout; t2 = monotonic_ms()) {
+ if (t2 - t1 >= retry_interval) {
+ for (qn = 0; qn < n_queries; qn++) {
+ if (queries[qn].rlen)
+ continue;
+
+ for (nn = 0; nn < n_ns; nn++) {
+ sendto(fd, queries[qn].query, queries[qn].qlen,
+ MSG_NOSIGNAL, &ns[nn].addr.u.sa, ns[nn].addr.len);
+ }
+ }
+
+ t1 = t2;
+ servfail_retry = 2 * n_queries;
+ }
+
+ /* Wait for a response, or until time to retry */
+ if (poll(&pfd, 1, t1 + retry_interval - t2) <= 0)
+ continue;
+
+ while (1) {
+ recvlen = recvfrom(fd, queries[next_query].reply,
+ sizeof(queries[next_query].reply), 0,
+ &from.u.sa, &from.len
+ );
+
+ /* read error */
+ if (recvlen < 0)
+ break;
+
+ /* Ignore non-identifiable packets */
+ if (recvlen < 4)
+ continue;
+
+ /* Ignore replies from addresses we didn't send to */
+ for (nn = 0; nn < n_ns; nn++)
+ if (memcmp(&from.u.sa, &ns[nn].addr.u.sa, from.len) == 0)
+ break;
+
+ if (nn >= n_ns)
+ continue;
+
+ /* Find which query this answer goes with, if any */
+ for (qn = next_query; qn < n_queries; qn++)
+ if (memcmp(queries[next_query].reply, queries[qn].query, 2) == 0)
+ break;
+
+ if (qn >= n_queries || queries[qn].rlen)
+ continue;
+
+ queries[qn].rcode = queries[next_query].reply[3] & 15;
+ queries[qn].latency = monotonic_ms() - t0;
+ queries[qn].n_ns = nn;
+
+ ns[nn].replies++;
+
+ /* Only accept positive or negative responses;
+ * retry immediately on server failure, and ignore
+ * all other codes such as refusal. */
+ switch (queries[qn].rcode) {
+ case 0:
+ case 3:
+ break;
+
+ case 2:
+ if (servfail_retry && servfail_retry--) {
+ ns[nn].failures++;
+ sendto(fd, queries[qn].query, queries[qn].qlen,
+ MSG_NOSIGNAL, &ns[nn].addr.u.sa, ns[nn].addr.len);
+ }
+ /* fall through */
+
+ default:
+ continue;
+ }
+
+ /* Store answer */
+ n_replies++;
+
+ queries[qn].rlen = recvlen;
+
+ if (qn == next_query) {
+ while (next_query < n_queries) {
+ if (!queries[next_query].rlen)
+ break;
+
+ next_query++;
+ }
+ }
+ else {
+ memcpy(queries[qn].reply, queries[next_query].reply, recvlen);
+ }
+
+ if (next_query >= n_queries)
+ return n_replies;
+ }
+ }
+
+ return n_replies;
+}
+
+///FIXME: use standard lsa = xhost2sockaddr(host, port) instead
+
+static struct ns *add_ns(struct ns **ns, int *n_ns, const char *addr)
+{
+ char portstr[sizeof("65535")], *p;
+ len_and_sockaddr a = { };
+ struct ns *tmp;
+ struct addrinfo *ai, *aip, hints = {
+ .ai_flags = AI_NUMERICSERV,
+ .ai_socktype = SOCK_DGRAM
+ };
+
+ dbg("%s: addr:'%s'\n", __func__, addr);
+
+ if (parse_nsaddr(addr, &a)) {
+ /* Maybe we got a domain name, attempt to resolve it using the standard
+ * resolver routines */
+
+ p = strchr(addr, '#');
+ snprintf(portstr, sizeof(portstr), "%hu",
+ (unsigned short)(p ? strtoul(p, NULL, 10) : G.default_port));
+
+ if (!getaddrinfo(addr, portstr, &hints, &ai)) {
+ for (aip = ai; aip; aip = aip->ai_next) {
+ if (aip->ai_addr->sa_family != AF_INET &&
+ aip->ai_addr->sa_family != AF_INET6)
+ continue;
+
+#if ! ENABLE_FEATURE_IPV6
+ if (aip->ai_addr->sa_family != AF_INET)
+ continue;
+#endif
+
+ tmp = realloc(*ns, sizeof(**ns) * (*n_ns + 1));
+
+ if (!tmp)
+ return NULL;
+
+ *ns = tmp;
+
+ (*ns)[*n_ns].name = addr;
+ (*ns)[*n_ns].replies = 0;
+ (*ns)[*n_ns].failures = 0;
+ (*ns)[*n_ns].addr.len = aip->ai_addrlen;
+
+ memcpy(&(*ns)[*n_ns].addr.u.sa, aip->ai_addr, aip->ai_addrlen);
+
+ (*n_ns)++;
+ }
+
+ freeaddrinfo(ai);
+
+ return &(*ns)[*n_ns];
+ }
+
+ return NULL;
+ }
+
+ tmp = xrealloc(*ns, sizeof(**ns) * (*n_ns + 1));
+ *ns = tmp;
+
+ (*ns)[*n_ns].addr = a;
+ (*ns)[*n_ns].name = addr;
+ (*ns)[*n_ns].replies = 0;
+ (*ns)[*n_ns].failures = 0;
+
+ return &(*ns)[(*n_ns)++];
+}
+
+static int parse_resolvconf(struct ns **ns, int *n_ns)
+{
+ int prev_n_ns = *n_ns;
+ FILE *resolv;
+
+ resolv = fopen("/etc/resolv.conf", "r");
+ if (resolv) {
+ char line[128], *p;
+
+ while (fgets(line, sizeof(line), resolv)) {
+ p = strtok(line, " \t\n");
+
+ if (!p || strcmp(p, "nameserver") != 0)
+ continue;
+
+ p = strtok(NULL, " \t\n");
+
+ if (!p)
+ continue;
+
+ if (!add_ns(ns, n_ns, xstrdup(p))) {
+ free(p);
+ break;
+ }
+ }
+
+ fclose(resolv);
+ }
+
+ return *n_ns - prev_n_ns;
+}
+
+static struct query *add_query(struct query **queries, int *n_queries,
+ int type, const char *dname)
+{
+ struct query *new_q;
+ int pos;
+ ssize_t qlen;
+
+ pos = *n_queries;
+ *n_queries = pos + 1;
+ *queries = new_q = xrealloc(*queries, sizeof(**queries) * (pos + 1));
+
+ dbg("new query#%u type %u for '%s'\n", pos, type, dname);
+ new_q += pos;
+ memset(new_q, 0, sizeof(*new_q));
+
+ qlen = res_mkquery(QUERY, dname, C_IN, type, NULL, 0, NULL,
+ new_q->query, sizeof(new_q->query));
+
+ new_q->qlen = qlen;
+ new_q->name = dname;
+
+ return new_q;
+}
+
+//FIXME: use xmalloc_sockaddr2dotted[_noport]() instead of sal2str()
+
+#define SIZEOF_SAL2STR_BUF (INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1 + 5 + 1)
+static char *sal2str(char buf[SIZEOF_SAL2STR_BUF], len_and_sockaddr *a)
+{
+ char *p = buf;
+
+#if ENABLE_FEATURE_IPV6
+ if (a->u.sa.sa_family == AF_INET6) {
+ inet_ntop(AF_INET6, &a->u.sin6.sin6_addr, buf, SIZEOF_SAL2STR_BUF);
+ p += strlen(p);
+
+ if (a->u.sin6.sin6_scope_id) {
+ if (if_indextoname(a->u.sin6.sin6_scope_id, p + 1)) {
+ *p++ = '%';
+ p += strlen(p);
+ }
+ }
+ } else
+#endif
+ {
+ inet_ntop(AF_INET, &a->u.sin.sin_addr, buf, SIZEOF_SAL2STR_BUF);
+ p += strlen(p);
+ }
+
+ sprintf(p, "#%hu", ntohs(a->u.sin.sin_port));
+
+ return buf;
+}
+
+int nslookup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int nslookup_main(int argc UNUSED_PARAM, char **argv)
+{
+ struct ns *ns;
+ struct query *queries;
+ llist_t *type_strings;
+ int n_ns, n_queries;
+ int bb_style_counter = 0;
+ unsigned types;
+ int rc;
+ int opts;
+ enum {
+ OPT_stats = (1 << 4),
+ };
+
+ INIT_G();
+
+ type_strings = NULL;
+#if ENABLE_FEATURE_NSLOOKUP_LONG_OPTIONS
+ opts = getopt32long(argv, "^"
+ "+" /* '+': stop at first non-option (why?) */
+ "q:*p:+r:+t:+s"
+ "\0"
+ "-1:q::", /* minimum 1 arg, -q is a list */
+ "type\0" Required_argument "q"
+ "querytype\0" Required_argument "q"
+ "port\0" Required_argument "p"
+ "retry\0" Required_argument "r"
+ "timeout\0" Required_argument "t"
+ "stats\0" No_argument "s",
+ &type_strings, &G.default_port,
+ &G.default_retry, &G.default_timeout
+ );
+#else
+ opts = getopt32(argv, "^"
+ "+" /* '+': stop at first non-option (why?) */
+ "q:*p:+r:+t:+s"
+ "\0"
+ "-1:q::", /* minimum 1 arg, -q is a list */
+ &type_strings, &G.default_port,
+ &G.default_retry, &G.default_timeout
+ );
+#endif
+ if (G.default_port > 65535)
+ bb_error_msg_and_die("invalid server port");
+ if (G.default_retry == 0)
+ bb_error_msg_and_die("invalid retry value");
+ if (G.default_timeout == 0)
+ bb_error_msg_and_die("invalid timeout value");
+
+ types = 0;
+ while (type_strings) {
+ int c;
+ char *ptr, *chr;
+
+ ptr = llist_pop(&type_strings);
+
+ /* skip leading text, e.g. when invoked with -querytype=AAAA */
+ chr = strchr(ptr, '=');
+ if (chr)
+ ptr = chr + 1;
+
+ for (c = 0;; c++) {
+ if (!qtypes[c].name)
+ bb_error_msg_and_die("invalid query type \"%s\"", ptr);
+ if (strcmp(qtypes[c].name, ptr) == 0)
+ break;
+ }
+
+ types |= (1 << c);
+ }
+
+ argv += optind;
+
+ n_queries = 0;
+ queries = NULL;
+ do {
+ /* No explicit type given, guess query type.
+ * If we can convert the domain argument into a ptr (means that
+ * inet_pton() could read it) we assume a PTR request, else
+ * we issue A+AAAA queries and switch to an output format
+ * mimicking the one of the traditional nslookup applet. */
+ if (types == 0) {
+ char *ptr;
+ char buf80[80];
+
+ ptr = make_ptr(buf80, *argv);
+
+ if (ptr) {
+ add_query(&queries, &n_queries, T_PTR, ptr);
+ }
+ else {
+ bb_style_counter = 1;
+ add_query(&queries, &n_queries, T_A, *argv);
+#if ENABLE_FEATURE_IPV6
+ add_query(&queries, &n_queries, T_AAAA, *argv);
+#endif
+ }
+ }
+ else {
+ int c;
+ for (c = 0; qtypes[c].name; c++) {
+ if (types & (1 << c))
+ add_query(&queries, &n_queries, qtypes[c].type,
+ *argv);
+ }
+ }
+ argv++;
+ } while (argv[0] && argv[1]);
+
+ /* Use given DNS server if present */
+ n_ns = 0;
+ ns = NULL;
+ if (argv[0]) {
+ if (!add_ns(&ns, &n_ns, argv[0]))
+ bb_error_msg_and_die("invalid NS server address \"%s\"", argv[0]);
+ } else {
+ parse_resolvconf(&ns, &n_ns);
+ /* Fall back to localhost if we could not find NS in resolv.conf */
+ if (n_ns == 0)
+ add_ns(&ns, &n_ns, "127.0.0.1");
+ }
+
+ for (rc = 0; rc < n_ns; rc++) {
+ int c = send_queries(&ns[rc], 1, queries, n_queries);
+ if (c < 0)
+ bb_perror_msg_and_die("can't send queries");
+ if (c > 0)
+ break;
+ rc++;
+ if (rc >= n_ns) {
+ fprintf(stderr,
+ ";; connection timed out; no servers could be reached\n\n");
+ return EXIT_FAILURE;
+ }
+ }
+
+ printf("Server:\t\t%s\n", ns[rc].name);
+ {
+ char buf[SIZEOF_SAL2STR_BUF];
+ printf("Address:\t%s\n", sal2str(buf, &ns[rc].addr));
+ }
+ if (opts & OPT_stats) {
+ printf("Replies:\t%d\n", ns[rc].replies);
+ printf("Failures:\t%d\n", ns[rc].failures);
+ }
+ printf("\n");
+
+ for (rc = 0; rc < n_queries; rc++) {
+ int c;
+
+ if (opts & OPT_stats) {
+ printf("Query #%d completed in %lums:\n", rc, queries[rc].latency);
+ }
+
+ if (queries[rc].rcode != 0) {
+ printf("** server can't find %s: %s\n", queries[rc].name,
+ rcodes[queries[rc].rcode]);
+ continue;
+ }
+
+ c = 0;
+
+ if (queries[rc].rlen) {
+ HEADER *header;
+
+ if (!bb_style_counter) {
+ header = (HEADER *)queries[rc].reply;
+ if (!header->aa)
+ printf("Non-authoritative answer:\n");
+ c = parse_reply(queries[rc].reply, queries[rc].rlen, NULL);
+ }
+ else {
+ c = parse_reply(queries[rc].reply, queries[rc].rlen,
+ &bb_style_counter);
+ }
+ }
+
+ if (c == 0)
+ printf("*** Can't find %s: No answer\n", queries[rc].name);
+ else if (c < 0)
+ printf("*** Can't find %s: Parse error\n", queries[rc].name);
+
+ if (!bb_style_counter)
+ printf("\n");
+ }
+
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(ns);
+ if (n_queries)
+ free(queries);
+ }
+
+ return EXIT_SUCCESS;
+}
+
+#endif
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