rwrap: SRV record can recurse into A or AAAA.

When querying for a SRV record, we'll need to include A or AAAA records
in additional section. Therefore, keep querying the host file until we
can either recurse the A/AAAA records or reach the recursion limit

Signed-off-by: Jakub Hrozek <jakub.hrozek@gmail.com>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/lib/resolv_wrapper/resolv_wrapper.c b/lib/resolv_wrapper/resolv_wrapper.c
index 0c079fe1fc444baefec2dea7e222bdc3a4bceb85..99c091d0de08e784d1471d0f8f584462cf2a5816 100644 (file)
--- a/lib/resolv_wrapper/resolv_wrapper.c
+++ b/lib/resolv_wrapper/resolv_wrapper.c
@@ -141,6 +141,8 @@ static void rwrap_log(enum rwrap_dbglvl_e dbglvl,
        }                                                       \
 } while(0);
 
+#define RWRAP_MAX_RECURSION 5
+
 /* Priority and weight can be omitted from the hosts file, but need to be part
  * of the output
  */
@@ -657,7 +659,25 @@ static ssize_t rwrap_fake_empty_query(const char *key,
         (strcasecmp(key, query)) == 0)
 
 
-static int rwrap_get_record(const char *hostfile,
+static int rwrap_get_record(const char *hostfile, unsigned recursion,
+                           const char *query, int type,
+                           struct rwrap_fake_rr *rr);
+
+static int rwrap_srv_recurse(const char *hostfile, unsigned recursion,
+                            const char *query, struct rwrap_fake_rr *rr)
+{
+       int rc;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_a, rr);
+       if (rc == 0) return 0;
+
+       rc = rwrap_get_record(hostfile, recursion, query, ns_t_aaaa, rr);
+       if (rc == ENOENT) rc = 0;
+
+       return rc;
+}
+
+static int rwrap_get_record(const char *hostfile, unsigned recursion,
                            const char *query, int type,
                            struct rwrap_fake_rr *rr)
 {
@@ -665,7 +685,12 @@ static int rwrap_get_record(const char *hostfile,
        char buf[BUFSIZ];
        char *key = NULL;
        char *value = NULL;
-       int rc = 0;
+       int rc = ENOENT;
+
+       if (recursion >= RWRAP_MAX_RECURSION) {
+               RWRAP_LOG(RWRAP_LOG_ERROR, "Recursed too deep!\n");
+               return -1;
+       }
 
        RWRAP_LOG(RWRAP_LOG_TRACE,
                  "Searching in fake hosts file %s\n", hostfile);
@@ -711,6 +736,11 @@ static int rwrap_get_record(const char *hostfile,
                } else if (TYPE_MATCH(type, ns_t_srv,
                                      rec_type, "SRV", key, query)) {
                        rc = rwrap_create_fake_srv_rr(key, value, rr);
+                       if (rc == 0) {
+                               rc = rwrap_srv_recurse(hostfile, recursion+1,
+                                               rr->rrdata.srv_rec.hostname,
+                                               rr + 1);
+                       }
                        break;
                } else if (TYPE_MATCH(type, ns_t_soa,
                                      rec_type, "SOA", key, query)) {
@@ -723,7 +753,7 @@ static int rwrap_get_record(const char *hostfile,
                }
        }
 
-       if (rc == 0 && rr->type == ns_t_invalid) {
+       if (rc == ENOENT && recursion == 0) {
                RWRAP_LOG(RWRAP_LOG_TRACE, "Record for [%s] not found\n", query);
                memcpy(rr->key, key, strlen(key) + 1);
        }
@@ -782,7 +812,7 @@ static int rwrap_res_fake_hosts(const char *hostfile,
        int rc = ENOENT;
        char *query_name = NULL;
        size_t qlen = strlen(query);
-       struct rwrap_fake_rr rr;
+       struct rwrap_fake_rr rrs[RWRAP_MAX_RECURSION];
        ssize_t resp_size;
 
        RWRAP_LOG(RWRAP_LOG_TRACE,
@@ -797,17 +827,26 @@ static int rwrap_res_fake_hosts(const char *hostfile,
                return -1;
        }
 
-       rwrap_fake_rr_init(&rr, 1);
+       rwrap_fake_rr_init(rrs, RWRAP_MAX_RECURSION);
 
-       rc = rwrap_get_record(hostfile, query_name, type, &rr);
-       if (rc != 0) {
+       rc = rwrap_get_record(hostfile, 0, query_name, type, rrs);
+       switch (rc) {
+       case 0:
+               RWRAP_LOG(RWRAP_LOG_TRACE,
+                               "Found record for [%s]\n", query_name);
+               break;
+       case ENOENT:
+               RWRAP_LOG(RWRAP_LOG_TRACE,
+                               "No record for [%s]\n", query_name);
+               break;
+       default:
                RWRAP_LOG(RWRAP_LOG_ERROR,
                                "Error searching for [%s]\n", query_name);
                free(query_name);
                return -1;
        }
 
-       resp_size = rwrap_fake_answer(&rr, type, answer, anslen);
+       resp_size = rwrap_fake_answer(rrs, type, answer, anslen);
        switch (resp_size) {
        case -1:
                RWRAP_LOG(RWRAP_LOG_ERROR,