MINOR: resolvers: Use milliseconds for cached items in resolver responses

The last time when an item was seen in a resolver responses is now stored in
milliseconds instead of seconds. This avoid some corner-cases at the
edges. This also simplifies time comparisons.

(cherry picked from commit 55c1c4053f70bf53adfcd5067fa959e20f2b44fe)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/include/haproxy/dns-t.h b/include/haproxy/dns-t.h
index 191edf6..95d4097 100644 (file)
--- a/include/haproxy/dns-t.h
+++ b/include/haproxy/dns-t.h
@@ -147,7 +147,7 @@ struct dns_answer_item {
        uint16_t        data_len;                    /* number of bytes in target below */
        struct sockaddr address;                     /* IPv4 or IPv6, network format */
        char            target[DNS_MAX_NAME_SIZE+1]; /* Response data: SRV or CNAME type target */
-       time_t          last_seen;                   /* When was the answer was last seen */
+       unsigned int    last_seen;                   /* When was the answer was last seen */
        struct dns_answer_item *ar_item;             /* pointer to a RRset from the additional section, if exists */
        struct list     list;
 };

diff --git a/src/dns.c b/src/dns.c
index a628c5c..c9ffcf7 100644 (file)
--- a/src/dns.c
+++ b/src/dns.c
@@ -629,7 +629,7 @@ static void dns_check_dns_response(struct dns_resolution *res)
                struct dns_answer_item *ar_item = item->ar_item;
 
                /* clean up obsolete Additional record */
-               if (ar_item && (ar_item->last_seen + resolvers->hold.obsolete / 1000) < now.tv_sec) {
+               if (ar_item && tick_is_lt(tick_add(ar_item->last_seen, resolvers->hold.obsolete), now_ms)) {
                        /* Cleaning up the AR item will trigger an extra DNS  resolution, except if the SRV
                         * item is also obsolete.
                         */
@@ -638,7 +638,7 @@ static void dns_check_dns_response(struct dns_resolution *res)
                }
 
                /* Remove obsolete items */
-               if ((item->last_seen + resolvers->hold.obsolete / 1000) < now.tv_sec) {
+               if (tick_is_lt(tick_add(item->last_seen, resolvers->hold.obsolete), now_ms)) {
                        if (item->type != DNS_RTYPE_SRV)
                                goto rm_obselete_item;
 
@@ -953,6 +953,7 @@ static int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend,
 
                /* initialization */
                dns_answer_record->ar_item = NULL;
+               dns_answer_record->last_seen = TICK_ETERNITY;
 
                offset = 0;
                len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
@@ -1148,12 +1149,12 @@ static int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend,
                }
 
                if (found == 1) {
-                       tmp_record->last_seen = now.tv_sec;
+                       tmp_record->last_seen = now_ms;
                        pool_free(dns_answer_item_pool, dns_answer_record);
                        dns_answer_record = NULL;
                }
                else {
-                       dns_answer_record->last_seen = now.tv_sec;
+                       dns_answer_record->last_seen = now_ms;
                        dns_answer_record->ar_item = NULL;
                        LIST_ADDQ(&dns_p->answer_list, &dns_answer_record->list);
                        dns_answer_record = NULL;
@@ -1203,6 +1204,7 @@ static int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend,
                dns_answer_record = pool_alloc(dns_answer_item_pool);
                if (dns_answer_record == NULL)
                        goto invalid_resp;
+               dns_answer_record->last_seen = TICK_ETERNITY;
 
                offset = 0;
                len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
@@ -1329,12 +1331,12 @@ static int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend,
                }
 
                if (found == 1) {
-                       tmp_record->ar_item->last_seen = now.tv_sec;
+                       tmp_record->ar_item->last_seen = now_ms;
                        pool_free(dns_answer_item_pool, dns_answer_record);
                        dns_answer_record = NULL;
                }
                else {
-                       dns_answer_record->last_seen = now.tv_sec;
+                       dns_answer_record->last_seen = now_ms;
                        dns_answer_record->ar_item = NULL;
 
                        // looking for the SRV record in the response list linked to this additional record