diff options
| -rw-r--r-- | dns.c | 43 | ||||
| -rw-r--r-- | dns.h | 12 | ||||
| -rw-r--r-- | dns_example.c | 8 |
3 files changed, 56 insertions, 7 deletions
@@ -174,6 +174,24 @@ static struct dns_answers *get_answers(char **reader, char *packet, int num) *((unsigned short *) res->data) = pref; memcpy(res->data + 2, name, strlen(name) + 1); free(name); + } else if (res->type == dns_type_srv) { + char *name; + unsigned short priority; + unsigned short weight; + unsigned short port; + priority = ntohs(*((unsigned short *) *reader)); + *reader += 2; + weight = ntohs(*((unsigned short *) *reader)); + *reader += 2; + port = ntohs(*((unsigned short *) *reader)); + *reader += 2; + name = read_name(reader, packet); + res->data = malloc(7 + strlen(name)); + ((unsigned short *) res->data)[0] = priority; + ((unsigned short *) res->data)[1] = weight; + ((unsigned short *) res->data)[2] = port; + memcpy(res->data + 6, name, strlen(name) + 1); + free(name); } else { if (res->type == dns_type_txt) { res->size--; @@ -208,14 +226,35 @@ static struct dns_answers *get(int sock, struct sockaddr_in *a) } +char *dns_mx_server(void *data) +{ + return ((char *) data) + 2; +} + int dns_mx_preference(void *data) { return *((unsigned short *) data); } -char *dns_mx_server(void *data) + +char *dns_srv_server(void *data) { - return ((char *) data) + 2; + return ((char *) data) + 6; +} + +int dns_srv_port(void *data) +{ + return ((unsigned short *) data)[2]; +} + +int dns_srv_priority(void *data) +{ + return *((unsigned short *) data); +} + +int dns_srv_weight(void *data) +{ + return ((unsigned short *) data)[1]; } @@ -6,7 +6,8 @@ enum { /* Some of DNS types: */ dns_type_a = 1, dns_type_cname = 5, dns_type_mx = 15, - dns_type_txt = 16 + dns_type_txt = 16, + dns_type_srv = 33 }; struct dns_answers { @@ -20,12 +21,15 @@ struct dns_answers { /* For CNAME & TXT data is just 'char *', * For A data is 'unsigned char *' of size 4. */ -int dns_mx_preference(void *data); char *dns_mx_server(void *data); +int dns_mx_preference(void *data); +char *dns_srv_server(void *data); +int dns_srv_port(void *data); +int dns_srv_priority(void *data); +int dns_srv_weight(void *data); -/* In case of error result is 0. - * It's not the-best-effort attempt to get answer, just simple working one. */ +/* In case of error result is 0. */ struct dns_answers *dns_get(const char *server, const char *host, int query); void dns_free(struct dns_answers *answers); diff --git a/dns_example.c b/dns_example.c index f6efeba..9f16dc0 100644 --- a/dns_example.c +++ b/dns_example.c @@ -10,12 +10,18 @@ int main() for (cur = ans; cur; cur = cur->next) { if (cur->type == dns_type_a) { unsigned char *ip = cur->data; - printf("IP of %s is %d.%d.%d.%d.\n", + printf("IP address of %s is %d.%d.%d.%d.\n", cur->host, ip[0], ip[1], ip[2], ip[3]); } else if (cur->type == dns_type_cname) { printf("Cannonical name of %s is %s.\n", cur->host, cur->data); } else if (cur->type == dns_type_txt) { printf("Text from %s: %s\n", cur->host, cur->data); + } else if (cur->type == dns_type_srv) { + printf("Service %s is located at %s on port %d " + "with priority %d and weight %d.\n", + cur->host, + dns_srv_server(cur->data), dns_srv_port(cur->data), + dns_srv_priority(cur->data), dns_srv_weight(cur->data)); } else if (cur->type == dns_type_mx) { printf("Mail exchange server for %s with preference %d is %s.\n", cur->host, |