From: Alejandro Colomar <alx@kernel.org>
Date: Thu, 25 May 2023 20:24:30 +0000 (+0200)
Subject: ROFL: Rolling on the floor looping
X-Git-Tag: 4.14.0-rc1~57
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2f9ca4b49d30c7095fab4f2e0f6a03afed6b906a;p=thirdparty%2Fshadow.git

ROFL: Rolling on the floor looping

Please tell me this was an easter egg :P

 #define go_banana() ({ goto nowhere; nowhere: 0-0; })

Closes: <https://github.com/shadow-maint/shadow/issues/736>
Easter-egg: 8492dee6632e ("subids: support nsswitch")
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

diff --git a/lib/nss.c b/lib/nss.c
index 30199a63e..b902e5d77 100644
--- a/lib/nss.c
+++ b/lib/nss.c
@@ -46,6 +46,8 @@ void nss_init(const char *nsswitch_path) {
 	char *line = NULL, *p, *token, *saveptr;
 	size_t len = 0;
 	FILE *shadow_logfd = log_get_logfd();
+	char libname[65];
+	void *h;
 
 	if (atomic_flag_test_and_set(&nss_init_started)) {
 		// Another thread has started nss_init, wait for it to complete
@@ -68,9 +70,6 @@ void nss_init(const char *nsswitch_path) {
 		return;
 	}
 	while ((getline(&line, &len, nssfp)) != -1) {
-		char libname[65];
-		void *h;
-
 		if (line[0] == '\0' || line[0] == '#')
 			continue;
 		if (strlen(line) < 8)
@@ -80,66 +79,65 @@ void nss_init(const char *nsswitch_path) {
 		p = &line[6];
 		while ((*p) && isspace(*p))
 			p++;
-		if (!*p)
-			continue;
-		token = strtok_r(p, " \n\t", &saveptr);
-		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;
-		}
-		if (strcmp(token, "files") == 0) {
-			subid_nss = NULL;
-			goto done;
-		}
-		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;
-		}
-		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;
-		}
-		subid_nss = MALLOC(struct subid_nss_ops);
-		if (!subid_nss) {
-			dlclose(h);
-			goto done;
-		}
-		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;
-		}
-		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;
-		}
-		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;
-		}
-		subid_nss->handle = h;
+		if (*p != '\0')
+			break;
+	}
+	token = strtok_r(p, " \n\t", &saveptr);
+	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;
+	}
+	if (strcmp(token, "files") == 0) {
+		subid_nss = NULL;
+		goto done;
+	}
+	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;
+	}
+	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;
+	}
+	subid_nss = MALLOC(struct subid_nss_ops);
+	if (!subid_nss) {
+		dlclose(h);
+		goto done;
+	}
+	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;
+	}
+	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;
+	}
+	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;
 	}
+	subid_nss->handle = h;
 
 done:
 	atomic_store(&nss_init_completed, true);