Add missing files

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@1559 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/dns.c b/dns.c
new file mode 100755 (executable)
index 0000000..74a3f32
--- /dev/null
+++ b/dns.c
@@ -0,0 +1,187 @@
+/*
+ * DNS Support for Asterisk
+ *
+ * Written by Thorsten Lockert <tholo@trollphone.org>
+ *
+ * Funding provided by Troll Phone Networks AS
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+#include <unistd.h>
+
+#include <asterisk/logger.h>
+#include <asterisk/channel.h>
+#include <asterisk/dns.h>
+
+#define MAX_SIZE 4096
+
+typedef struct {
+       unsigned        id :16;         /* query identification number */
+#if BYTE_ORDER == BIG_ENDIAN
+                       /* fields in third byte */
+       unsigned        qr: 1;          /* response flag */
+       unsigned        opcode: 4;      /* purpose of message */
+       unsigned        aa: 1;          /* authoritive answer */
+       unsigned        tc: 1;          /* truncated message */
+       unsigned        rd: 1;          /* recursion desired */
+                       /* fields in fourth byte */
+       unsigned        ra: 1;          /* recursion available */
+       unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
+       unsigned        ad: 1;          /* authentic data from named */
+       unsigned        cd: 1;          /* checking disabled by resolver */
+       unsigned        rcode :4;       /* response code */
+#endif
+#if BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
+                       /* fields in third byte */
+       unsigned        rd :1;          /* recursion desired */
+       unsigned        tc :1;          /* truncated message */
+       unsigned        aa :1;          /* authoritive answer */
+       unsigned        opcode :4;      /* purpose of message */
+       unsigned        qr :1;          /* response flag */
+                       /* fields in fourth byte */
+       unsigned        rcode :4;       /* response code */
+       unsigned        cd: 1;          /* checking disabled by resolver */
+       unsigned        ad: 1;          /* authentic data from named */
+       unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
+       unsigned        ra :1;          /* recursion available */
+#endif
+                       /* remaining bytes */
+       unsigned        qdcount :16;    /* number of question entries */
+       unsigned        ancount :16;    /* number of answer entries */
+       unsigned        nscount :16;    /* number of authority entries */
+       unsigned        arcount :16;    /* number of resource entries */
+} dns_HEADER;
+
+struct dn_answer {
+       unsigned short rtype;
+       unsigned short class;
+       unsigned int ttl;
+       unsigned short size;
+} __attribute__ ((__packed__));
+
+static int skip_name(u_char *s, int len)
+{
+       int x = 0;
+
+       while (x < len) {
+               if (*s == '\0') {
+                       s++;
+                       x++;
+                       break;
+               }
+               if ((*s & 0xc0) == 0xc0) {
+                       s += 2;
+                       x += 2;
+                       break;
+               }
+               x += *s + 1;
+               s += *s + 1;
+       }
+       if (x >= len)
+               return -1;
+       return x;
+}
+
+static int dns_parse_answer(void *context,
+                                                       int class, int type, u_char *answer, int len,
+                                                       int (*callback)(void *context, u_char *answer, int len, u_char *fullanswer))
+{
+       u_char *fullanswer = answer;
+       struct dn_answer *ans;
+       dns_HEADER *h;
+       int res;
+       int x;
+
+    h = (dns_HEADER *)answer;
+       answer += sizeof(dns_HEADER);
+       len -= sizeof(dns_HEADER);
+
+       for (x = 0; x < ntohs(h->qdcount); x++) {
+               if ((res = skip_name(answer, len)) < 0) {
+                       ast_log(LOG_WARNING, "Couldn't skip over name\n");
+                       return -1;
+               }
+               answer += res + 4;      /* Skip name and QCODE / QCLASS */
+               len -= res + 4;
+               if (len < 0) {
+                       ast_log(LOG_WARNING, "Strange query size\n");
+                       return -1;
+               }
+       }
+
+       for (x = 0; x < ntohs(h->ancount); x++) {
+               if ((res = skip_name(answer, len)) < 0) {
+                       ast_log(LOG_WARNING, "Failed skipping name\n");
+                       return -1;
+               }
+               answer += res;
+               len -= res;
+               ans = (struct dn_answer *)answer;
+               answer += sizeof(struct dn_answer);
+               len -= sizeof(struct dn_answer);
+               if (len < 0) {
+                       ast_log(LOG_WARNING, "Strange result size\n");
+                       return -1;
+               }
+               if (len < 0) {
+                       ast_log(LOG_WARNING, "Length exceeds frame\n");
+                       return -1;
+               }
+
+               if (ntohs(ans->class) == class && ntohs(ans->rtype) == type) {
+                       if (callback) {
+                               if ((res = callback(context, answer, ntohs(ans->size), fullanswer)) < 0)
+                                       ast_log(LOG_WARNING, "Failed to parse result\n");
+                               if (res > 0)
+                                       return 1;
+                       }
+               }
+               answer += ntohs(ans->size);
+               len -= ntohs(ans->size);
+       }
+       return 0;
+}
+
+int ast_search_dns(void *context,
+                                  const char *dname, int class, int type,
+                                  int (*callback)(void *context, u_char *answer, int len, u_char *fullanswer))
+{
+#ifdef __Linux__
+       struct __res_state dnsstate;
+#endif
+       char answer[MAX_SIZE];
+       int res, ret = -1;
+
+#ifdef __Linux__
+       res_ninit(&dnsstate);
+       res = res_nsearch(&dnsstate, dname, class, type, answer, sizeof(answer));
+#else
+       res_init();
+       res = res_search(dname, class, type, answer, sizeof(answer));
+#endif
+       if (res > 0) {
+               if ((res = dns_parse_answer(context, class, type, answer, res, callback)) < 0) {
+                       ast_log(LOG_WARNING, "Parse error\n");
+                       ret = -1;
+               }
+               else if (ret == 0) {
+                       ast_log(LOG_DEBUG, "No matches found\n");
+                       ret = 0;
+               }
+               else
+                       ret = 1;
+       }
+#ifdef __Linux__
+       res_nclose(&srvstate);
+#else
+       res_close();
+#endif
+       return ret;
+}

diff --git a/include/asterisk/dns.h b/include/asterisk/dns.h
new file mode 100755 (executable)
index 0000000..a0a64e3
--- /dev/null
+++ b/include/asterisk/dns.h
@@ -0,0 +1,20 @@
+/*
+ * DNS support
+ * 
+ * Written by Thorsten Lockert <tholo@trollphone.org>
+ *
+ * Funding provided by Troll Phone Networks AS
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#ifndef _ASTERISK_DNS_H
+#define _ASTERISK_DNS_H
+
+struct ast_channel;
+
+extern int ast_search_dns(void *context, const char *dname, int class, int type,
+                         int (*callback)(void *context, u_char *answer, int len, u_char *fullanswer));
+
+#endif /* _ASTERISK_DNS_H */