Changeset 1355 for pjproject/trunk/pjlib-util/src/pjlib-util/dns.c

Timestamp:

Jun 11, 2007 4:43:29 PM (17 years ago)

Author:

bennylp

Message:

Ticket #328: Possible alignment error in DNS

File:

• pjproject/trunk/pjlib-util/src/pjlib-util/dns.c (modified) (8 diffs)

pjproject/trunk/pjlib-util/src/pjlib-util/dns.c

@@ -42 +42 @@
 
 
+static void write16(pj_uint8_t *p, pj_uint16_t val)
+{
+    p[0] = (pj_uint8_t)(val >> 8);
+    p[1] = (pj_uint8_t)(val & 0xFF);
+}
+
+
 /**
  * Initialize a DNS query transaction.
@@ -51 +58 @@
                                        const pj_str_t *name)
 {
-    pj_dns_hdr *hdr;
-    char *query, *p;
+    pj_uint8_t *query, *p = packet;
     const char *startlabel, *endlabel, *endname;
-    pj_uint16_t tmp;
     unsigned d;
 
@@ -67 +72 @@
 
     /* Initialize header */
-    hdr = (pj_dns_hdr*) packet;
-    pj_bzero(hdr, sizeof(struct pj_dns_hdr));
-    hdr->id = pj_htons(id);
-    hdr->flags = pj_htons(PJ_DNS_SET_RD(1));
-    hdr->qdcount = pj_htons(1);
+    pj_assert(sizeof(pj_dns_hdr)==12);
+    pj_bzero(p, sizeof(struct pj_dns_hdr));
+    write16(p+0, id);
+    write16(p+2, (pj_uint16_t)PJ_DNS_SET_RD(1));
+    write16(p+4, (pj_uint16_t)1);
 
     /* Initialize query */
-    query = p = (char*)(hdr+1);
+    query = p = ((pj_uint8_t*)packet)+sizeof(pj_dns_hdr);
 
     /* Tokenize name */
@@ -82 +87 @@
         while (endlabel != endname && *endlabel != '.')
             ++endlabel;
-        *p++ = (char)(endlabel - startlabel);
+        *p++ = (pj_uint8_t)(endlabel - startlabel);
         pj_memcpy(p, startlabel, endlabel-startlabel);
         p += (endlabel-startlabel);
@@ -92 +97 @@
 
     /* Set type */
-    tmp = pj_htons((pj_uint16_t)(qtype));
-    pj_memcpy(p, &tmp, 2);
+    write16(p, (pj_uint16_t)qtype);
     p += 2;
 
     /* Set class (IN=1) */
-    tmp = pj_htons(1);
-    pj_memcpy(p, &tmp, 2);
+    write16(p, 1);
     p += 2;
 
     /* Done, calculate length */
-    *size = p - (char*)packet;
+    *size = p - (pj_uint8_t*)packet;
 
     return 0;
@@ -112 +115 @@
  */
 static pj_status_t get_name_len(int rec_counter, const pj_uint8_t *pkt, 
-                                const pj_uint8_t *start, const pj_uint8_t *max,
+                                const pj_uint8_t *start, const pj_uint8_t *max, 
                                 int *parsed_len, int *name_len)
 {
@@ -240 +243 @@
 
 
-/* Skip query records. */
+/* Parse query records. */
 static pj_status_t parse_query(pj_dns_parsed_query *q, pj_pool_t *pool,
                                const pj_uint8_t *pkt, const pj_uint8_t *start,
@@ -327 +330 @@
     /* Get TTL */
     pj_memcpy(&rr->ttl, p, 4);
-    rr->ttl = pj_htonl(rr->ttl);
+    rr->ttl = pj_ntohl(rr->ttl);
     p += 4;
 
     /* Get rdlength */
     pj_memcpy(&rr->rdlength, p, 2);
-    rr->rdlength = pj_htons(rr->rdlength);
+    rr->rdlength = pj_ntohs(rr->rdlength);
     p += 2;