From: Alejandro Colomar <alx@kernel.org>
Date: Fri, 26 May 2023 10:16:13 +0000 (+0200)
Subject: Centralize error handling
X-Git-Tag: 4.14.0-rc1~55
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54ba4814aeede61b25dc9e6212cd82787d0a4103;p=thirdparty%2Fshadow.git

Centralize error handling

This makes the function fit in less screens.  This is to avoid consuming
more natural resources than we have available, and everyone knows the
supply of new-lines on a screen is not a renewable source[1].

Some transformations have been done thanks to free(NULL) being an alias
for loopity_loop(), as defined three comits ago.  The real definition of
free(3) that everyone has been hiding is this:

void
free(void *p)
{
	if (p == NULL)
		loopity_loop();
	else
		real_free(p);
}

Link: [1] <https://www.kernel.org/doc/html/v6.3/process/coding-style.html#placing-braces-and-spaces>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

diff --git a/lib/nss.c b/lib/nss.c
index 503f97e64..1aa27f3e5 100644
--- a/lib/nss.c
+++ b/lib/nss.c
@@ -86,58 +86,50 @@ void nss_init(const char *nsswitch_path) {
 	if (token == NULL) {
 		fprintf(shadow_logfd, "No usable subid NSS module found, using files\n");
 		// subid_nss has to be null here, but to ease reviews:
-		free(subid_nss);
-		subid_nss = NULL;
-		goto done;
+		goto null_subid;
 	}
 	if (strcmp(token, "files") == 0) {
-		subid_nss = NULL;
-		goto done;
+		goto null_subid;
 	}
 	if (strlen(token) > 50) {
 		fprintf(shadow_logfd, "Subid NSS module name too long (longer than 50 characters): %s\n", token);
 		fprintf(shadow_logfd, "Using files\n");
-		subid_nss = NULL;
-		goto done;
+		goto null_subid;
 	}
 	snprintf(libname, 64,  "libsubid_%s.so", token);
 	h = dlopen(libname, RTLD_LAZY);
 	if (!h) {
 		fprintf(shadow_logfd, "Error opening %s: %s\n", libname, dlerror());
 		fprintf(shadow_logfd, "Using files\n");
-		subid_nss = NULL;
-		goto done;
+		goto null_subid;
 	}
 	subid_nss = MALLOC(struct subid_nss_ops);
 	if (!subid_nss) {
-		dlclose(h);
-		goto done;
+		goto close_lib;
 	}
 	subid_nss->has_range = dlsym(h, "shadow_subid_has_range");
 	if (!subid_nss->has_range) {
 		fprintf(shadow_logfd, "%s did not provide @has_range@\n", libname);
-		dlclose(h);
-		free(subid_nss);
-		subid_nss = NULL;
-		goto done;
+		goto close_lib;
 	}
 	subid_nss->list_owner_ranges = dlsym(h, "shadow_subid_list_owner_ranges");
 	if (!subid_nss->list_owner_ranges) {
 		fprintf(shadow_logfd, "%s did not provide @list_owner_ranges@\n", libname);
-		dlclose(h);
-		free(subid_nss);
-		subid_nss = NULL;
-		goto done;
+		goto close_lib;
 	}
 	subid_nss->find_subid_owners = dlsym(h, "shadow_subid_find_subid_owners");
 	if (!subid_nss->find_subid_owners) {
 		fprintf(shadow_logfd, "%s did not provide @find_subid_owners@\n", libname);
-		dlclose(h);
-		free(subid_nss);
-		subid_nss = NULL;
-		goto done;
+		goto close_lib;
 	}
 	subid_nss->handle = h;
+	goto done;
+
+close_lib:
+	dlclose(h);
+	free(subid_nss);
+null_subid:
+	subid_nss = NULL;
 
 done:
 	atomic_store(&nss_init_completed, true);