test: Add testing module and some unittests for bridges.c.

This roughly doubles our test coverage of the bridges.c module.

 * ADD new testing module, .../src/test/test_bridges.c.
 * CHANGE a few function declarations from `static` to `STATIC`.
 * CHANGE one function in transports.c, transport_get_by_name(), to be
   mockable.
 * CLOSES #25425: https://bugs.torproject.org/25425

4 files changed, 25 insertions, 9 deletions

diff --git a/src/or/bridges.c b/src/or/bridges.c
index d88d6c6434..4ee3550048 100644
--- a/src/or/bridges.c
+++ b/src/or/bridges.c
@@ -11,6 +11,8 @@
  * Bridges are fixed entry nodes, used for censorship circumvention.
  **/
 
+#define TOR_BRIDGES_PRIVATE
+
 #include "or.h"
 #include "bridges.h"
 #include "circuitbuild.h"
@@ -93,7 +95,7 @@ sweep_bridge_list(void)
 }
 
 /** Initialize the bridge list to empty, creating it if needed. */
-static void
+STATIC void
 clear_bridge_list(void)
 {
   if (!bridge_list)
@@ -156,7 +158,7 @@ bridge_get_addr_port(const bridge_info_t *bridge)
  * bridge with no known digest whose address matches any of the
  * tor_addr_port_t's in <b>orports</b>, return that bridge.  Else return
  * NULL. */
-static bridge_info_t *
+STATIC bridge_info_t *
 get_configured_bridge_by_orports_digest(const char *digest,
                                         const smartlist_t *orports)
 {
@@ -350,7 +352,7 @@ bridge_has_digest(const bridge_info_t *bridge, const char *digest)
  * existing bridge with the same address and port, and warn the user as
  * appropriate.
  */
-static void
+STATIC void
 bridge_resolve_conflicts(const tor_addr_t *addr, uint16_t port,
                          const char *digest, const char *transport_name)
 {
@@ -472,7 +474,7 @@ bridge_add_from_config(bridge_line_t *bridge_line)
 }
 
 /** If <b>digest</b> is one of our known bridges, return it. */
-bridge_info_t *
+STATIC bridge_info_t *
 find_bridge_by_digest(const char *digest)
 {
   if (! bridge_list)
diff --git a/src/or/bridges.h b/src/or/bridges.h
index 54a6250259..3108eb555d 100644
--- a/src/or/bridges.h
+++ b/src/or/bridges.h
@@ -20,7 +20,6 @@ typedef struct bridge_info_t bridge_info_t;
 void mark_bridge_list(void);
 void sweep_bridge_list(void);
 const smartlist_t *bridge_list_get(void);
-bridge_info_t *find_bridge_by_digest(const char *digest);
 const uint8_t *bridge_get_rsa_id_digest(const bridge_info_t *bridge);
 const tor_addr_port_t * bridge_get_addr_port(const bridge_info_t *bridge);
 bridge_info_t *get_configured_bridge_by_addr_port_digest(
@@ -65,5 +64,17 @@ MOCK_DECL(download_status_t *, get_bridge_dl_status_by_id,
 
 void bridges_free_all(void);
 
+#ifdef TOR_BRIDGES_PRIVATE
+STATIC void clear_bridge_list(void);
+STATIC bridge_info_t *find_bridge_by_digest(const char *digest);
+STATIC bridge_info_t *get_configured_bridge_by_orports_digest(
+                                                  const char *digest,
+                                                  const smartlist_t *orports);
+STATIC void bridge_resolve_conflicts(const tor_addr_t *addr,
+                                     uint16_t port,
+                                     const char *digest,
+                                     const char *transport_name);
+#endif /* defined(TOR_BRIDGES_PRIVATE) */
+
 #endif /* !defined(TOR_BRIDGES_H) */
 
diff --git a/src/or/transports.c b/src/or/transports.c
index b08dcd1613..fb6c29de7e 100644
--- a/src/or/transports.c
+++ b/src/or/transports.c
@@ -135,7 +135,7 @@ static smartlist_t *transport_list = NULL;
 /** Returns a transport_t struct for a transport proxy supporting the
     protocol <b>name</b> listening at <b>addr</b>:<b>port</b> using
     SOCKS version <b>socks_ver</b>. */
-static transport_t *
+STATIC transport_t *
 transport_new(const tor_addr_t *addr, uint16_t port,
               const char *name, int socks_ver,
               const char *extra_info_args)
@@ -222,8 +222,8 @@ transport_copy(const transport_t *transport)
 
 /** Returns the transport in our transport list that has the name <b>name</b>.
  *  Else returns NULL. */
-transport_t *
-transport_get_by_name(const char *name)
+MOCK_IMPL(transport_t *,
+transport_get_by_name,(const char *name))
 {
   tor_assert(name);
 
diff --git a/src/or/transports.h b/src/or/transports.h
index 1b2786472c..022b926a03 100644
--- a/src/or/transports.h
+++ b/src/or/transports.h
@@ -38,7 +38,7 @@ MOCK_DECL(int, transport_add_from_config,
 void transport_free_(transport_t *transport);
 #define transport_free(tr) FREE_AND_NULL(transport_t, transport_free_, (tr))
 
-transport_t *transport_get_by_name(const char *name);
+MOCK_DECL(transport_t*, transport_get_by_name, (const char *name));
 
 MOCK_DECL(void, pt_kickstart_proxy,
           (const smartlist_t *transport_list, char **proxy_argv,
@@ -113,6 +113,9 @@ typedef struct {
   smartlist_t *transports;
 } managed_proxy_t;
 
+STATIC transport_t *transport_new(const tor_addr_t *addr, uint16_t port,
+                                  const char *name, int socks_ver,
+                                  const char *extra_info_args);
 STATIC int parse_cmethod_line(const char *line, managed_proxy_t *mp);
 STATIC int parse_smethod_line(const char *line, managed_proxy_t *mp);