X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=extras%2Fvolume_id%2Fvol_id.c;h=0427d70da199e312e518c5e48792350de9cc4e26;hp=7bdfda17e7ab5b967ac923935cbee08c7351e140;hb=e18e6d79996edeeb07e122f3582a688c3ef4f6b9;hpb=708cb3594139f28f7d99b4ea1cf91b4ccd032273

diff --git a/extras/volume_id/vol_id.c b/extras/volume_id/vol_id.c
index 7bdfda17e..0427d70da 100644
--- a/extras/volume_id/vol_id.c
+++ b/extras/volume_id/vol_id.c
@@ -27,6 +27,8 @@
 #include <unistd.h>
 #include <string.h>
 #include <ctype.h>
+#include <errno.h>
+#include <pwd.h>
 #include <grp.h>
 #include <sys/ioctl.h>
 
@@ -114,6 +116,7 @@ int main(int argc, char *argv[])
 			    "  -t             filesystem type\n"
 			    "  -l             filesystem label\n"
 			    "  -u             filesystem uuid\n"
+			    "  -L             raw label\n"
 			    " --skip-raid     don't probe for raid\n"
 			    " --probe-all     find possibly conflicting signatures\n"
 			    " --help\n"
@@ -123,6 +126,7 @@ int main(int argc, char *argv[])
 		PRINT_TYPE,
 		PRINT_LABEL,
 		PRINT_UUID,
+		PRINT_RAW_LABEL,
 	} print = PRINT_EXPORT;
 	struct volume_id *vid = NULL;
 	static char name[VOLUME_ID_LABEL_SIZE];
@@ -131,8 +135,7 @@ int main(int argc, char *argv[])
 	int skip_raid = 0;
 	int probe_all = 0;
 	const char *node = NULL;
-	uid_t nobody_uid;
-	gid_t nobody_gid;
+	struct passwd *pw;
 	int retval;
 	int rc = 0;
 
@@ -152,6 +155,8 @@ int main(int argc, char *argv[])
 			print = PRINT_LABEL;
 		} else if (strcmp(arg, "-u") == 0) {
 			print = PRINT_UUID;
+		} else if (strcmp(arg, "-L") == 0) {
+			print = PRINT_RAW_LABEL;
 		} else if (strcmp(arg, "--skip-raid") == 0) {
 			skip_raid = 1;
 		} else if (strcmp(arg, "--probe-all") == 0) {
@@ -178,15 +183,17 @@ int main(int argc, char *argv[])
 
 	if (ioctl(vid->fd, BLKGETSIZE64, &size) != 0)
 		size = 0;
-	dbg("BLKGETSIZE64=%llu", size);
+	dbg("BLKGETSIZE64=%llu", (unsigned long long)size);
 
-	/* drop all privileges */
-	nobody_uid = lookup_user("nobody");
-	nobody_gid = lookup_group("nogroup");
-	if (nobody_uid > 0 && nobody_gid > 0) {
+	/* try to drop all privileges before reading disk content */
+	pw = getpwnam ("nobody");
+	if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
+		dbg("dropping privileges to %u:%u",
+		    (unsigned int)pw->pw_uid, (unsigned int)pw->pw_gid);
 		if (setgroups(0, NULL) != 0 ||
-		    setgid(nobody_gid) != 0 ||
-		    setuid(nobody_uid) != 0) {
+		    setgid(pw->pw_gid) != 0 ||
+		    setuid(pw->pw_uid) != 0) {
+			fprintf(stderr, "error dropping privileges: %s\n", strerror(errno));
 			rc = 3;
 			goto exit;
 		}
@@ -304,6 +311,13 @@ int main(int argc, char *argv[])
 		}
 		printf("%s\n", vid->uuid);
 		break;
+	case PRINT_RAW_LABEL:
+		if (vid->label[0] == '\0' || vid->usage_id == VOLUME_ID_RAID) {
+			rc = 3;
+			goto exit;
+		}
+		printf("%s\n", vid->label);
+		break;
 	}
 
 exit: