From 7f1ebb0bcb5c480ea0e21f24f8b348a85313087b Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 21 Jul 2016 17:57:57 +0200 Subject: [PATCH] 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/libelogind/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. --- src/libelogind/sd-id128/id128-util.c | 171 +++++++++++++++++++++++++++ src/libelogind/sd-id128/id128-util.h | 45 +++++++ src/libelogind/sd-id128/sd-id128.c | 114 ++++-------------- 3 files changed, 241 insertions(+), 89 deletions(-) create mode 100644 src/libelogind/sd-id128/id128-util.c create mode 100644 src/libelogind/sd-id128/id128-util.h diff --git a/src/libelogind/sd-id128/id128-util.c b/src/libelogind/sd-id128/id128-util.c new file mode 100644 index 000000000..5d4fcb8f5 --- /dev/null +++ b/src/libelogind/sd-id128/id128-util.c @@ -0,0 +1,171 @@ +/*** + This file is part of elogind. + + Copyright 2016 Lennart Poettering + + elogind 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. + + elogind 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 elogind; If not, see . +***/ + +#include + +#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/libelogind/sd-id128/id128-util.h b/src/libelogind/sd-id128/id128-util.h new file mode 100644 index 000000000..4a04c80d2 --- /dev/null +++ b/src/libelogind/sd-id128/id128-util.h @@ -0,0 +1,45 @@ +#pragma once + +/*** + This file is part of elogind. + + Copyright 2016 Lennart Poettering + + elogind 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. + + elogind 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 elogind; If not, see . +***/ + +#include + +#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/libelogind/sd-id128/sd-id128.c b/src/libelogind/sd-id128/sd-id128.c index d9c0116f6..1470e4c01 100644 --- a/src/libelogind/sd-id128/sd-id128.c +++ b/src/libelogind/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) { -- 2.30.2