MINOR: server: server_find functions: id, name, best_match

This patch introduces three new functions which can be used to find a
server in a farm using different server information:
- server unique id (srv->puid)
- server name
- find best match using either name or unique id

When performing best matching, the following applies:
 - use the server name first (if provided)
 - use the server id if provided
 in any case, the function can update the caller about mismatches
 encountered.

diff --git a/include/proto/server.h b/include/proto/server.h
index 0a0ccc396b7d1a606971b08e5a91f22e50f0f16b..e63d7c5e774807c15ab48e79cc583dcb9c0c9d7c 100644 (file)
--- a/include/proto/server.h
+++ b/include/proto/server.h
@@ -40,6 +40,9 @@ int srv_lastsession(const struct server *s);
 int srv_getinter(const struct check *check);
 int parse_server(const char *file, int linenum, char **args, struct proxy *curproxy, struct proxy *defproxy);
 int update_server_addr(struct server *s, void *ip, int ip_sin_family, char *updater);
+struct server *server_find_by_id(struct proxy *bk, int id);
+struct server *server_find_by_name(struct proxy *bk, const char *name);
+struct server *server_find_best_match(struct proxy *bk, char *name, int id, int *diff);
 
 /* functions related to server name resolution */
 int snr_update_srv_status(struct server *s);

diff --git a/src/server.c b/src/server.c
index 901967421f51ecde3e00ac92ce709a79f88e9060..503d53ab36fc5688454b53dd0d7e88577df6ca46 100644 (file)
--- a/src/server.c
+++ b/src/server.c
@@ -1794,6 +1794,126 @@ int parse_server(const char *file, int linenum, char **args, struct proxy *curpr
        return err_code;
 }
 
+/* Returns a pointer to the first server matching either id <id>.
+ * NULL is returned if no match is found.
+ * the lookup is performed in the backend <bk>
+ */
+struct server *server_find_by_id(struct proxy *bk, int id)
+{
+       struct eb32_node *eb32;
+       struct server *curserver;
+
+       if (!bk || (id ==0))
+               return NULL;
+
+       /* <bk> has no backend capabilities, so it can't have a server */
+       if (!(bk->cap & PR_CAP_BE))
+               return NULL;
+
+       curserver = NULL;
+
+       eb32 = eb32_lookup(&bk->conf.used_server_id, id);
+       if (eb32)
+               curserver = container_of(eb32, struct server, conf.id);
+
+       return curserver;
+}
+
+/* Returns a pointer to the first server matching either name <name>, or id
+ * if <name> starts with a '#'. NULL is returned if no match is found.
+ * the lookup is performed in the backend <bk>
+ */
+struct server *server_find_by_name(struct proxy *bk, const char *name)
+{
+       struct server *curserver;
+
+       if (!bk || !name)
+               return NULL;
+
+       /* <bk> has no backend capabilities, so it can't have a server */
+       if (!(bk->cap & PR_CAP_BE))
+               return NULL;
+
+       curserver = NULL;
+       if (*name == '#') {
+               curserver = server_find_by_id(bk, atoi(name + 1));
+               if (curserver)
+                       return curserver;
+       }
+       else {
+               curserver = bk->srv;
+
+               while (curserver && (strcmp(curserver->id, name) != 0))
+                       curserver = curserver->next;
+
+               if (curserver)
+                       return curserver;
+       }
+
+       return NULL;
+}
+
+struct server *server_find_best_match(struct proxy *bk, char *name, int id, int *diff)
+{
+       struct server *byname;
+       struct server *byid;
+
+       if (!name && !id)
+               return NULL;
+
+       if (diff)
+               *diff = 0;
+
+       byname = byid = NULL;
+
+       if (name) {
+               byname = server_find_by_name(bk, name);
+               if (byname && (!id || byname->puid == id))
+                       return byname;
+       }
+
+       /* remaining possibilities :
+        *  - name not set
+        *  - name set but not found
+        *  - name found but ID doesn't match
+        */
+       if (id) {
+               byid = server_find_by_id(bk, id);
+               if (byid) {
+                       if (byname) {
+                               /* use id only if forced by configuration */
+                               if (byid->flags & SRV_F_FORCED_ID) {
+                                       if (diff)
+                                               *diff |= 2;
+                                       return byid;
+                               }
+                               else {
+                                       if (diff)
+                                               *diff |= 1;
+                                       return byname;
+                               }
+                       }
+
+                       /* remaining possibilities:
+                        *   - name not set
+                        *   - name set but not found
+                        */
+                       if (name && diff)
+                               *diff |= 2;
+                       return byid;
+               }
+
+               /* id bot found */
+               if (byname) {
+                       if (diff)
+                               *diff |= 1;
+                       return byname;
+               }
+       }
+
+       return NULL;
+}
+
 /*
  * update a server's current IP address.
  * ip is a pointer to the new IP address, whose address family is ip_sin_family.