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authorLennart Poettering <lennart@poettering.net>2016-07-21 17:57:57 +0200
committerLennart Poettering <lennart@poettering.net>2016-07-22 12:59:36 +0200
commit910fd145f46f0916adbc6035b0433eb586bd6ce0 (patch)
treeb341a8ec1ed60cdf1459fd8c77435b3d079901f7 /src/libsystemd/sd-id128
parent3bbaff3e08070f03487958818edbd161d439ce15 (diff)
sd-id128: split UUID file read/write code into new id128-util.[ch]
We currently have code to read and write files containing UUIDs at various places. Unify this in id128-util.[ch], and move some other stuff there too. The new files are located in src/libsystemd/sd-id128/ (instead of src/shared/), because they are actually the backend of sd_id128_get_machine() and sd_id128_get_boot(). In follow-up patches we can use this reduce the code in nspawn and machine-id-setup by adopted the common implementation.
Diffstat (limited to 'src/libsystemd/sd-id128')
-rw-r--r--src/libsystemd/sd-id128/id128-util.c171
-rw-r--r--src/libsystemd/sd-id128/id128-util.h45
-rw-r--r--src/libsystemd/sd-id128/sd-id128.c114
3 files changed, 241 insertions, 89 deletions
diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
new file mode 100644
index 0000000000..c1742cab0e
--- /dev/null
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -0,0 +1,171 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2016 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <fcntl.h>
+
+#include "fd-util.h"
+#include "hexdecoct.h"
+#include "id128-util.h"
+#include "io-util.h"
+#include "stdio-util.h"
+
+char *id128_to_uuid_string(sd_id128_t id, char s[37]) {
+ unsigned n, k = 0;
+
+ assert(s);
+
+ /* Similar to sd_id128_to_string() but formats the result as UUID instead of plain hex chars */
+
+ for (n = 0; n < 16; n++) {
+
+ if (IN_SET(n, 4, 6, 8, 10))
+ s[k++] = '-';
+
+ s[k++] = hexchar(id.bytes[n] >> 4);
+ s[k++] = hexchar(id.bytes[n] & 0xF);
+ }
+
+ assert(k == 36);
+
+ s[k] = 0;
+
+ return s;
+}
+
+bool id128_is_valid(const char *s) {
+ size_t i, l;
+
+ assert(s);
+
+ l = strlen(s);
+ if (l == 32) {
+
+ /* Plain formatted 128bit hex string */
+
+ for (i = 0; i < l; i++) {
+ char c = s[i];
+
+ if (!(c >= '0' && c <= '9') &&
+ !(c >= 'a' && c <= 'z') &&
+ !(c >= 'A' && c <= 'Z'))
+ return false;
+ }
+
+ } else if (l == 36) {
+
+ /* Formatted UUID */
+
+ for (i = 0; i < l; i++) {
+ char c = s[i];
+
+ if ((i == 8 || i == 13 || i == 18 || i == 23)) {
+ if (c != '-')
+ return false;
+ } else {
+ if (!(c >= '0' && c <= '9') &&
+ !(c >= 'a' && c <= 'z') &&
+ !(c >= 'A' && c <= 'Z'))
+ return false;
+ }
+ }
+
+ } else
+ return false;
+
+ return true;
+}
+
+int id128_read_fd(int fd, Id128Format f, sd_id128_t *ret) {
+ char buffer[36 + 2];
+ ssize_t l;
+
+ assert(fd >= 0);
+ assert(f < _ID128_FORMAT_MAX);
+
+ /* Reads an 128bit ID from a file, which may either be in plain format (32 hex digits), or in UUID format, both
+ * followed by a newline and nothing else. */
+
+ l = loop_read(fd, buffer, sizeof(buffer), false); /* we expect a short read of either 33 or 37 chars */
+ if (l < 0)
+ return (int) l;
+ if (l == 0) /* empty? */
+ return -ENOMEDIUM;
+
+ if (l == 33) {
+ if (f == ID128_UUID)
+ return -EINVAL;
+
+ if (buffer[32] != '\n')
+ return -EINVAL;
+
+ buffer[32] = 0;
+
+ } else if (l == 37) {
+ if (f == ID128_PLAIN)
+ return -EINVAL;
+
+ if (buffer[36] != '\n')
+ return -EINVAL;
+
+ buffer[36] = 0;
+ } else
+ return -EINVAL;
+
+ return sd_id128_from_string(buffer, ret);
+}
+
+int id128_read(const char *p, Id128Format f, sd_id128_t *ret) {
+ _cleanup_close_ int fd = -1;
+
+ fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ return id128_read_fd(fd, f, ret);
+}
+
+int id128_write_fd(int fd, Id128Format f, sd_id128_t id) {
+ char buffer[36 + 2];
+ size_t sz;
+
+ assert(fd >= 0);
+ assert(f < _ID128_FORMAT_MAX);
+
+ if (f != ID128_UUID) {
+ sd_id128_to_string(id, buffer);
+ buffer[32] = '\n';
+ sz = 33;
+ } else {
+ id128_to_uuid_string(id, buffer);
+ buffer[36] = '\n';
+ sz = 37;
+ }
+
+ return loop_write(fd, buffer, sz, false);
+}
+
+int id128_write(const char *p, Id128Format f, sd_id128_t id) {
+ _cleanup_close_ int fd = -1;
+
+ fd = open(p, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
+ if (fd < 0)
+ return -errno;
+
+ return id128_write_fd(fd, f, id);
+}
diff --git a/src/libsystemd/sd-id128/id128-util.h b/src/libsystemd/sd-id128/id128-util.h
new file mode 100644
index 0000000000..73e4c710c4
--- /dev/null
+++ b/src/libsystemd/sd-id128/id128-util.h
@@ -0,0 +1,45 @@
+#pragma once
+
+/***
+ This file is part of systemd.
+
+ Copyright 2016 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+
+#include "sd-id128.h"
+#include "macro.h"
+
+char *id128_to_uuid_string(sd_id128_t id, char s[37]);
+
+/* Like SD_ID128_FORMAT_STR, but formats as UUID, not in plain format */
+#define ID128_UUID_FORMAT_STR "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x"
+
+bool id128_is_valid(const char *s) _pure_;
+
+typedef enum Id128Format {
+ ID128_ANY,
+ ID128_PLAIN, /* formatted as 32 hex chars as-is */
+ ID128_UUID, /* formatted as 36 character uuid string */
+ _ID128_FORMAT_MAX,
+} Id128Format;
+
+int id128_read_fd(int fd, Id128Format f, sd_id128_t *ret);
+int id128_read(const char *p, Id128Format f, sd_id128_t *ret);
+
+int id128_write_fd(int fd, Id128Format f, sd_id128_t id);
+int id128_write(const char *p, Id128Format f, sd_id128_t id);
diff --git a/src/libsystemd/sd-id128/sd-id128.c b/src/libsystemd/sd-id128/sd-id128.c
index d9c0116f60..1470e4c01a 100644
--- a/src/libsystemd/sd-id128/sd-id128.c
+++ b/src/libsystemd/sd-id128/sd-id128.c
@@ -25,6 +25,7 @@
#include "fd-util.h"
#include "hexdecoct.h"
+#include "id128-util.h"
#include "io-util.h"
#include "macro.h"
#include "random-util.h"
@@ -93,117 +94,52 @@ _public_ int sd_id128_from_string(const char s[], sd_id128_t *ret) {
return 0;
}
-static sd_id128_t make_v4_uuid(sd_id128_t id) {
- /* Stolen from generate_random_uuid() of drivers/char/random.c
- * in the kernel sources */
-
- /* Set UUID version to 4 --- truly random generation */
- id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40;
-
- /* Set the UUID variant to DCE */
- id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80;
-
- return id;
-}
-
_public_ int sd_id128_get_machine(sd_id128_t *ret) {
- static thread_local sd_id128_t saved_machine_id;
- static thread_local bool saved_machine_id_valid = false;
- _cleanup_close_ int fd = -1;
- char buf[33];
- unsigned j;
- sd_id128_t t;
+ static thread_local sd_id128_t saved_machine_id = {};
int r;
assert_return(ret, -EINVAL);
- if (saved_machine_id_valid) {
- *ret = saved_machine_id;
- return 0;
- }
-
- fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
- if (fd < 0)
- return -errno;
-
- r = loop_read_exact(fd, buf, 33, false);
- if (r < 0)
- return r;
- if (buf[32] !='\n')
- return -EIO;
-
- for (j = 0; j < 16; j++) {
- int a, b;
-
- a = unhexchar(buf[j*2]);
- b = unhexchar(buf[j*2+1]);
+ if (sd_id128_is_null(saved_machine_id)) {
+ r = id128_read("/etc/machine-id", ID128_PLAIN, &saved_machine_id);
+ if (r < 0)
+ return r;
- if (a < 0 || b < 0)
- return -EIO;
-
- t.bytes[j] = a << 4 | b;
+ if (sd_id128_is_null(saved_machine_id))
+ return -EINVAL;
}
- saved_machine_id = t;
- saved_machine_id_valid = true;
-
- *ret = t;
+ *ret = saved_machine_id;
return 0;
}
_public_ int sd_id128_get_boot(sd_id128_t *ret) {
- static thread_local sd_id128_t saved_boot_id;
- static thread_local bool saved_boot_id_valid = false;
- _cleanup_close_ int fd = -1;
- char buf[36];
- unsigned j;
- sd_id128_t t;
- char *p;
+ static thread_local sd_id128_t saved_boot_id = {};
int r;
assert_return(ret, -EINVAL);
- if (saved_boot_id_valid) {
- *ret = saved_boot_id;
- return 0;
+ if (sd_id128_is_null(saved_boot_id)) {
+ r = id128_read("/proc/sys/kernel/random/boot_id", ID128_UUID, &saved_boot_id);
+ if (r < 0)
+ return r;
}
- fd = open("/proc/sys/kernel/random/boot_id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
- if (fd < 0)
- return -errno;
-
- r = loop_read_exact(fd, buf, 36, false);
- if (r < 0)
- return r;
-
- for (j = 0, p = buf; j < 16; j++) {
- int a, b;
-
- if (p >= buf + 35)
- return -EIO;
-
- if (*p == '-') {
- p++;
- if (p >= buf + 35)
- return -EIO;
- }
-
- a = unhexchar(p[0]);
- b = unhexchar(p[1]);
-
- if (a < 0 || b < 0)
- return -EIO;
+ *ret = saved_boot_id;
+ return 0;
+}
- t.bytes[j] = a << 4 | b;
+static sd_id128_t make_v4_uuid(sd_id128_t id) {
+ /* Stolen from generate_random_uuid() of drivers/char/random.c
+ * in the kernel sources */
- p += 2;
- }
+ /* Set UUID version to 4 --- truly random generation */
+ id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40;
- saved_boot_id = t;
- saved_boot_id_valid = true;
+ /* Set the UUID variant to DCE */
+ id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80;
- *ret = t;
- return 0;
+ return id;
}
_public_ int sd_id128_randomize(sd_id128_t *ret) {