vol_id: make the --offset= argument optional

[elogind.git] / extras / volume_id / vol_id.c

diff --git a/extras/volume_id/vol_id.c b/extras/volume_id/vol_id.c
index cb1d455891a906341af0495895518f1ca854b0e0..b3f810fc9d3d6082af10e4ad8e1a132fcc44c617 100644 (file)
--- a/extras/volume_id/vol_id.c
+++ b/extras/volume_id/vol_id.c
@@ -34,7 +34,7 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 
-#include "../../udev.h"
+#include "../../udev/udev.h"
 #include "lib/libvolume_id.h"
 
 #define BLKGETSIZE64 _IOR(0x12,114,size_t)
@@ -134,6 +134,7 @@ int main(int argc, char *argv[])
                { "export", 0, NULL, 'x' },
                { "skip-raid", 0, NULL, 's' },
                { "probe-all", 0, NULL, 'a' },
+               { "offset", 2, NULL, 'o' },
                { "help", 0, NULL, 'h' },
                {}
        };
@@ -147,13 +148,14 @@ int main(int argc, char *argv[])
        } print = PRINT_EXPORT;
 
        struct volume_id *vid = NULL;
-       char label_safe[128];
-       char uuid_safe[128];
+       char label_safe[256];
+       char label_enc[256];
+       char uuid_enc[256];
        uint64_t size;
        int skip_raid = 0;
        int probe_all = 0;
+       uint64_t offset = 0;
        const char *node;
-       struct passwd *pw;
        int fd;
        const char *label, *uuid, *type, *type_version, *usage;
        int retval;
@@ -167,7 +169,7 @@ int main(int argc, char *argv[])
        while (1) {
                int option;
 
-               option = getopt_long(argc, argv, "lLutxsah", options, NULL);
+               option = getopt_long(argc, argv, "lLutxsaoh", options, NULL);
                if (option == -1)
                        break;
 
@@ -193,6 +195,10 @@ int main(int argc, char *argv[])
                case 'a':
                        probe_all = 1;
                        break;
+               case 'o':
+                       if (optarg[0] != '\0')
+                               offset = strtoull(optarg, NULL, 0);
+                       break;
                case 'h':
                        printf("Usage: vol_id [options] <device>\n"
                            " --export        export key/value pairs\n"
@@ -202,6 +208,7 @@ int main(int argc, char *argv[])
                            " --uuid          filesystem uuid\n"
                            " --skip-raid     don't probe for raid\n"
                            " --probe-all     find possibly conflicting signatures\n"
+                           " --offset        skip given number of bytes of input\n"
                            " --help\n\n");
                        goto exit;
                default:
@@ -212,7 +219,7 @@ int main(int argc, char *argv[])
 
        node = argv[optind];
        if (!node) {
-               err("no device");
+               err("no device\n");
                fprintf(stderr, "no device\n");
                rc = 1;
                goto exit;
@@ -233,31 +240,30 @@ int main(int argc, char *argv[])
 
        if (ioctl(fd, BLKGETSIZE64, &size) != 0)
                size = 0;
-       dbg("BLKGETSIZE64=%llu", (unsigned long long)size);
+       dbg("BLKGETSIZE64=%llu\n", (unsigned long long)size);
 
        /* 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(pw->pw_gid) != 0 ||
-                   setuid(pw->pw_uid) != 0) {
-                       fprintf(stderr, "error dropping privileges: %s\n", strerror(errno));
-                       rc = 3;
-                       goto exit;
+       if (getuid() == 0) {
+               struct passwd *pw;
+
+               pw = getpwnam("nobody");
+               if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
+                       if (setgroups(0, NULL) != 0 ||
+                           setgid(pw->pw_gid) != 0 ||
+                           setuid(pw->pw_uid) != 0)
+                               info("unable to drop privileges: %s\n\n", strerror(errno));
                }
        }
 
        if (probe_all) {
-               volume_id_all_probers(all_probers, vid, 0, size, NULL);
+               volume_id_all_probers(all_probers, vid, offset, size, NULL);
                goto exit;
        }
 
        if (skip_raid)
-               retval = volume_id_probe_filesystem(vid, 0, size);
+               retval = volume_id_probe_filesystem(vid, offset, size);
        else
-               retval = volume_id_probe_all(vid, 0, size);
+               retval = volume_id_probe_all(vid, offset, size);
        if (retval != 0) {
                fprintf(stderr, "%s: unknown volume type\n", node);
                rc = 4;
@@ -274,9 +280,10 @@ int main(int argc, char *argv[])
        }
 
        set_str(label_safe, label, sizeof(label_safe));
-       replace_untrusted_chars(label_safe);
-       set_str(uuid_safe, uuid, sizeof(uuid_safe));
-       replace_untrusted_chars(uuid_safe);
+       replace_chars(label_safe, ALLOWED_CHARS_INPUT);
+
+       volume_id_encode_string(label, label_enc, sizeof(label_enc));
+       volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
 
        switch (print) {
        case PRINT_EXPORT:
@@ -284,8 +291,9 @@ int main(int argc, char *argv[])
                printf("ID_FS_TYPE=%s\n", type);
                printf("ID_FS_VERSION=%s\n", type_version);
                printf("ID_FS_UUID=%s\n", uuid);
-               printf("ID_FS_UUID_SAFE=%s\n", uuid_safe);
+               printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
                printf("ID_FS_LABEL=%s\n", label);
+               printf("ID_FS_LABEL_ENC=%s\n", label_enc);
                printf("ID_FS_LABEL_SAFE=%s\n", label_safe);
                break;
        case PRINT_TYPE:
@@ -299,11 +307,11 @@ int main(int argc, char *argv[])
                printf("%s\n", label_safe);
                break;
        case PRINT_UUID:
-               if (uuid_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
+               if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
                        rc = 4;
                        goto exit;
                }
-               printf("%s\n", uuid_safe);
+               printf("%s\n", uuid_enc);
                break;
        case PRINT_LABEL_RAW:
                if (label[0] == '\0' || strcmp(usage, "raid") == 0) {