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-rw-r--r--toys/pending/host.c251
1 files changed, 251 insertions, 0 deletions
diff --git a/toys/pending/host.c b/toys/pending/host.c
new file mode 100644
index 00000000..4e1a7e7e
--- /dev/null
+++ b/toys/pending/host.c
@@ -0,0 +1,251 @@
+/* host.c - DNS lookup utility
+ *
+ * Copyright 2014 Rich Felker <dalias@aerifal.cx>
+ *
+ * No standard, but there's a version in bind9
+
+USE_HOST(NEWTOY(host, "<1>2avt:", TOYFLAG_USR|TOYFLAG_BIN))
+
+config HOST
+ bool "host"
+ default n
+ help
+ usage: host [-av] [-t TYPE] NAME [SERVER]
+
+ Perform DNS lookup on NAME, which can be a domain name to lookup,
+ or an ipv4 dotted or ipv6 colon seprated address to reverse lookup.
+ SERVER (if present) is the DNS server to use.
+
+ -a no idea
+ -t not a clue
+ -v verbose
+*/
+
+#define FOR_host
+#include "toys.h"
+
+GLOBALS(
+ char *type_str;
+)
+
+#include <resolv.h>
+
+#define PL_IP 1
+#define PL_NAME 2
+#define PL_DATA 3
+#define PL_TEXT 4
+#define PL_SOA 5
+#define PL_MX 6
+#define PL_SRV 7
+
+static const struct rrt {
+ const char *name;
+ const char *msg;
+ int pl;
+ int af;
+} rrt[] = {
+ [1] = { "A", "has address", PL_IP, AF_INET },
+ [28] = { "AAAA", "has address", PL_IP, AF_INET6 },
+ [2] = { "NS", "name server", PL_NAME },
+ [5] = { "CNAME", "is a nickname for", PL_NAME },
+ [16] = { "TXT", "descriptive text", PL_TEXT },
+ [6] = { "SOA", "start of authority", PL_SOA },
+ [12] = { "PTR", "domain name pointer", PL_NAME },
+ [15] = { "MX", "mail is handled", PL_MX },
+ [33] = { "SRV", "mail is handled", PL_SRV },
+ [255] = { "*", 0, 0 },
+};
+
+static const char rct[16][32] = {
+ "Success",
+ "Format error",
+ "Server failure",
+ "Non-existant domain",
+ "Not implemented",
+ "Refused",
+};
+
+void host_main(void)
+{
+ int verbose=(toys.optflags & (FLAG_a|FLAG_v)), type;
+ char *name, *nsname;
+ int i, j, ret, sec, count, rcode, qlen, alen, pllen = 0, v[5];
+ unsigned ttl, pri;
+ unsigned char qbuf[280], abuf[512], *p;
+ char rrname[256], plname[640], ptrbuf[64];
+ struct addrinfo *ai, iplit_hints = { .ai_flags = AI_NUMERICHOST };
+
+ name = *toys.optargs;
+ nsname = toys.optargs[1];
+
+ if (!TT.type_str && (toys.optflags & FLAG_a)) TT.type_str = "255";
+ if (!getaddrinfo(name, 0, &iplit_hints, &ai)) {
+ switch (ai->ai_family) {
+ unsigned char *a;
+ static const char xdigits[] = "0123456789abcdef";
+ case AF_INET:
+ a = (void *)&((struct sockaddr_in *)ai->ai_addr)->sin_addr;
+ snprintf(ptrbuf, sizeof ptrbuf,
+ "%d.%d.%d.%d.in-addr.arpa",
+ a[3], a[2], a[1], a[0]);
+ break;
+ case AF_INET6:
+ a = (void *)&((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr;
+ for (j=0, i=15; i>=0; i--) {
+ ptrbuf[j++] = xdigits[a[i]&15];
+ ptrbuf[j++] = '.';
+ ptrbuf[j++] = xdigits[a[i]>>4];
+ ptrbuf[j++] = '.';
+ }
+ strcpy(ptrbuf+j, "ip6.arpa");
+ break;
+ }
+ name = ptrbuf;
+ if (!TT.type_str) TT.type_str="12";
+ } else {
+ if (!TT.type_str) TT.type_str="1";
+ }
+
+ if (TT.type_str[0]-'0' < 10u) {
+ type = atoi(TT.type_str);
+ } else {
+ type = -1;
+ for (i=0; i < sizeof rrt / sizeof *rrt; i++) {
+ if (rrt[i].name && !strcasecmp(TT.type_str, rrt[i].name)) {
+ type = i;
+ break;
+ }
+ }
+ if (!strcasecmp(TT.type_str, "any")) type = 255;
+ if (type < 0) {
+ fprintf(stderr, "Invalid query type: %s\n", TT.type_str);
+ goto out_error;
+ }
+ }
+
+ qlen = res_mkquery(0, name, 1, type, 0, 0, 0, qbuf, sizeof qbuf);
+ if (qlen < 0) {
+ fprintf(stderr, "Invalid query parameters: %s", name);
+ goto out_error;
+ }
+
+ if (nsname) {
+ struct addrinfo ns_hints = { .ai_socktype = SOCK_DGRAM };
+ if ((ret = getaddrinfo(nsname, "53", &ns_hints, &ai)) < 0) {
+ fprintf(stderr, "Error looking up server name: %s\n",
+ gai_strerror(ret));
+ goto out_error;
+ }
+ int s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+ if (s < 0 || connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
+ fprintf(stderr, "Socket error: %s\n", strerror(errno));
+ goto out_error;
+ }
+ setsockopt(s, SOL_SOCKET, SO_RCVTIMEO,
+ &(struct timeval){ .tv_sec = 5 },
+ sizeof (struct timeval));
+ printf("Using domain server %s:\n", nsname);
+ send(s, qbuf, qlen, 0);
+ alen = recv(s, abuf, sizeof abuf, 0);
+ } else {
+ alen = res_send(qbuf, qlen, abuf, sizeof abuf);
+ }
+
+ if (alen < 12) {
+ fprintf(stderr, "Host not found, try again.\n");
+ goto out_error;
+ }
+
+ rcode = abuf[3] & 15;
+
+ if (verbose) {
+ printf("rcode = %d (%s), ancount = %d\n",
+ rcode, rct[rcode], 256*abuf[6] + abuf[7]);
+ if (!(abuf[2] & 4))
+ printf("The following answer is not authoritative:\n");
+ }
+
+ if (rcode) {
+ fprintf(stderr, "Host not found.\n");
+ if (!verbose) goto out_error;
+ }
+
+ p = abuf + 12;
+ for (sec=0; sec<4; sec++) {
+ count = 256*abuf[4+2*sec] + abuf[5+2*sec];
+ if (verbose && count>0 && sec>1) {
+ puts(sec==2 ? "For authoritative answers, see:"
+ : "Additional information:");
+ }
+ for (; count--; p += pllen) {
+ p += dn_expand(abuf, abuf+alen, p, rrname, sizeof rrname);
+ type = 256*p[0] + p[1];
+ p += 4;
+ if (!sec) continue;
+ ttl = 16777216*p[0] + 65536*p[1] + 256*p[2] + p[3];
+ p += 4;
+ pllen = 256*p[0] + p[1];
+ p += 2;
+ switch (type<sizeof rrt/sizeof *rrt ? rrt[type].pl : 0) {
+ case PL_IP:
+ inet_ntop(rrt[type].af, p, plname, sizeof plname);
+ break;
+ case PL_NAME:
+ dn_expand(abuf, abuf+alen, p, plname, sizeof plname);
+ break;
+ case PL_TEXT:
+ snprintf(plname, sizeof plname, "\"%.*s\"", pllen, p);
+ break;
+ case PL_SOA:
+ i = dn_expand(abuf, abuf+alen, p, plname, sizeof plname - 1);
+ strcat(plname, " ");
+ i += dn_expand(abuf, abuf+alen, p+i, plname+strlen(plname),
+ sizeof plname-strlen(plname));
+ for (j=0; j<5; j++)
+ v[j] = 16777216*p[i+4*j] + 65536*p[1+i+4*j]
+ + 256*p[2+i+4*j] + p[3+i+4*j];
+ snprintf(plname+strlen(plname),
+ sizeof plname-strlen(plname),
+ "(\n\t\t%zu\t;serial (version)\n"
+ "\t\t%zu\t;refresh period\n"
+ "\t\t%zu\t;retry interval\n"
+ "\t\t%zu\t;expire time\n"
+ "\t\t%zu\t;default ttl\n"
+ "\t\t)", v[0], v[1], v[2], v[3], v[4]);
+ break;
+ case PL_MX:
+ pri = 256*p[0] + p[1];
+ snprintf(plname, sizeof plname,
+ verbose ? "%d " : "(pri=%d) by ", pri);
+ dn_expand(abuf, abuf+alen, p+2,
+ plname+strlen(plname),
+ sizeof plname - strlen(plname));
+ break;
+ case PL_SRV:
+ for (j=0; j<3; j++)
+ v[j] = 256*p[2*j] + p[1+2*j];
+ snprintf(plname, sizeof plname,
+ "%d %d %d ", v[0], v[1], v[2]);
+ dn_expand(abuf, abuf+alen, p+6,
+ plname+strlen(plname),
+ sizeof plname - strlen(plname));
+ break;
+ default:
+ printf("%s unsupported RR type %u\n", rrname, type);
+ continue;
+ }
+ if (verbose) {
+ printf("%s\t%u\t%s %s\t%s\n",
+ rrname, ttl, "IN", rrt[type].name, plname);
+ } else if (rrt[type].msg) {
+ printf("%s %s %s\n", rrname, rrt[type].msg, plname);
+ }
+ }
+ if (!verbose && sec==1) break;
+ }
+ toys.exitval = rcode;
+ return;
+
+out_error:
+ toys.exitval = 1;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 08:44:17 +0000