MINOR: dns: give ability to dns_init_resolvers() to close a socket when requested

The function dns_init_resolvers() is used to initialize socket used to
send DNS queries.
This patch gives the function the ability to close a socket before
re-opening it.

[wt: this needs to be backported to 1.7 for next fix]
This commit is contained in:
Baptiste Assmann 2017-02-02 22:44:15 +01:00 committed by Willy Tarreau
parent 4dc7197338
commit 5cd1b9222e
3 changed files with 18 additions and 4 deletions

View File

@ -30,7 +30,7 @@ int dns_str_to_dn_label_len(const char *string);
int dns_hostname_validation(const char *string, char **err);
int dns_build_query(int query_id, int query_type, char *hostname_dn, int hostname_dn_len, char *buf, int bufsize);
struct task *dns_process_resolve(struct task *t);
int dns_init_resolvers(void);
int dns_init_resolvers(int close_socket);
uint16_t dns_rnd16(void);
int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend, struct dns_response_packet *dns_p);
int dns_get_ip_from_response(struct dns_response_packet *dns_p,

View File

@ -919,11 +919,13 @@ unsigned short dns_response_get_query_id(unsigned char *resp)
* parses resolvers sections and initializes:
* - task (time events) for each resolvers section
* - the datagram layer (network IO events) for each nameserver
* It takes one argument:
* - close_first takes 2 values: 0 or 1. If 1, the connection is closed first.
* returns:
* 0 in case of error
* 1 when no error
*/
int dns_init_resolvers(void)
int dns_init_resolvers(int close_socket)
{
struct dns_resolvers *curr_resolvers;
struct dns_nameserver *curnameserver;
@ -961,7 +963,19 @@ int dns_init_resolvers(void)
curr_resolvers->t = t;
list_for_each_entry(curnameserver, &curr_resolvers->nameserver_list, list) {
if ((dgram = calloc(1, sizeof(*dgram))) == NULL) {
dgram = NULL;
if (close_socket == 1) {
if (curnameserver->dgram) {
close(curnameserver->dgram->t.sock.fd);
memset(curnameserver->dgram, '\0', sizeof(*dgram));
dgram = curnameserver->dgram;
}
}
/* allocate memory only if it has not already been allocated
* by a previous call to this function */
if (!dgram && (dgram = calloc(1, sizeof(*dgram))) == NULL) {
Alert("Starting [%s/%s] nameserver: out of memory.\n", curr_resolvers->id,
curnameserver->id);
return 0;

View File

@ -1176,7 +1176,7 @@ static void init(int argc, char **argv)
exit(1);
/* initialize structures for name resolution */
if (!dns_init_resolvers())
if (!dns_init_resolvers(0))
exit(1);
free(err_msg);