[v3,2/3] credential-cache: check for windows specific errors

Commit Message

Carlo Marcelo Arenas Belón Sept. 14, 2021, 7:25 a.m. UTC

Connect and reset errors aren't what will be expected by POSIX but
are instead compatible with the ones used by WinSock.

To avoid any possibility of confusion with other systems, checks
for disconnection and availability had been abstracted into helper
functions that are platform specific.

Signed-off-by: Carlo Marcelo Arenas Belón <[e-mail]>
---
v3:
* use a better define as suggested by Dscho
v2:
* Use helper functions to separate error handling as suggested by Junio

 builtin/credential-cache.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

Comments

Junio C Hamano Sept. 14, 2021, 4:43 p.m. UTC | #1

Carlo Marcelo Arenas Belón  <[e-mail]> writes:

> @@ -75,7 +101,7 @@ static void do_cache(const char *socket, const char *action, int timeout,
>  	}
>  
>  	if (send_request(socket, &buf) < 0) {
> -		if (errno != ENOENT && errno != ECONNREFUSED)
> +		if (connection_fatally_broken(errno))
>  			die_errno("unable to connect to cache daemon");
>  		if (flags & FLAG_SPAWN) {
>  			spawn_daemon(socket);

In my earlier review I suggested a helper that checks
recoverability, hence leading to a code structure like this:

		if (!connection_not_yet_open(errno))
			die_errno(...);
		/* otherwise, (re)establish connection and retry */
		...

but the phrasing and semantics you chose to check for unrecoverable
state reads much better.

Thanks.

Patch

diff --git a/builtin/credential-cache.c b/builtin/credential-cache.c
index e8a7415747..78c02ad531 100644
--- a/builtin/credential-cache.c
+++ b/builtin/credential-cache.c
@@ -11,6 +11,32 @@ 
 #define FLAG_SPAWN 0x1
 #define FLAG_RELAY 0x2
 
+#ifdef GIT_WINDOWS_NATIVE
+
+static int connection_closed(int error)
+{
+	return (error == EINVAL);
+}
+
+static int connection_fatally_broken(int error)
+{
+	return (error != ENOENT) && (error != ENETDOWN);
+}
+
+#else
+
+static int connection_closed(int error)
+{
+	return (error == ECONNRESET);
+}
+
+static int connection_fatally_broken(int error)
+{
+	return (error != ENOENT) && (error != ECONNREFUSED);
+}
+
+#endif
+
 static int send_request(const char *socket, const struct strbuf *out)
 {
 	int got_data = 0;
@@ -28,7 +54,7 @@  static int send_request(const char *socket, const struct strbuf *out)
 		int r;
 
 		r = read_in_full(fd, in, sizeof(in));
-		if (r == 0 || (r < 0 && errno == ECONNRESET))
+		if (r == 0 || (r < 0 && connection_closed(errno)))
 			break;
 		if (r < 0)
 			die_errno("read error from cache daemon");
@@ -75,7 +101,7 @@  static void do_cache(const char *socket, const char *action, int timeout,
 	}
 
 	if (send_request(socket, &buf) < 0) {
-		if (errno != ENOENT && errno != ECONNREFUSED)
+		if (connection_fatally_broken(errno))
 			die_errno("unable to connect to cache daemon");
 		if (flags & FLAG_SPAWN) {
 			spawn_daemon(socket);