diff options
Diffstat (limited to 'src/libsystemd/sd-id128/id128-util.c')
| -rw-r--r-- | src/libsystemd/sd-id128/id128-util.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c new file mode 100644 index 0000000..a3f6da6 --- /dev/null +++ b/src/libsystemd/sd-id128/id128-util.c @@ -0,0 +1,212 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> + +#include "fd-util.h" +#include "fs-util.h" +#include "hexdecoct.h" +#include "id128-util.h" +#include "io-util.h" +#include "stdio-util.h" +#include "string-util.h" + +char *id128_to_uuid_string(sd_id128_t id, char s[static ID128_UUID_STRING_MAX]) { + 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 (IN_SET(i, 8, 13, 18, 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 + * optionally followed by a newline and nothing else. ID files should really be newline terminated, but if they + * aren't that's OK too, following the rule of "Be conservative in what you send, be liberal in what you + * accept". */ + + l = loop_read(fd, buffer, sizeof(buffer), false); /* we expect a short read of either 32/33 or 36/37 chars */ + if (l < 0) + return (int) l; + if (l == 0) /* empty? */ + return -ENOMEDIUM; + + switch (l) { + + case 13: + case 14: + /* Treat an "uninitialized" id file like an empty one */ + return f == ID128_PLAIN_OR_UNINIT && strneq(buffer, "uninitialized\n", l) ? -ENOMEDIUM : -EINVAL; + + case 33: /* plain UUID with trailing newline */ + if (buffer[32] != '\n') + return -EINVAL; + + _fallthrough_; + case 32: /* plain UUID without trailing newline */ + if (f == ID128_UUID) + return -EINVAL; + + buffer[32] = 0; + break; + + case 37: /* RFC UUID with trailing newline */ + if (buffer[36] != '\n') + return -EINVAL; + + _fallthrough_; + case 36: /* RFC UUID without trailing newline */ + if (IN_SET(f, ID128_PLAIN, ID128_PLAIN_OR_UNINIT)) + return -EINVAL; + + buffer[36] = 0; + break; + + default: + 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, bool do_sync) { + char buffer[36 + 2]; + size_t sz; + int r; + + 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; + } + + r = loop_write(fd, buffer, sz, false); + if (r < 0) + return r; + + if (do_sync) { + if (fsync(fd) < 0) + return -errno; + + r = fsync_directory_of_file(fd); + if (r < 0) + return r; + } + + return 0; +} + +int id128_write(const char *p, Id128Format f, sd_id128_t id, bool do_sync) { + _cleanup_close_ int fd = -1; + + fd = open(p, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_TRUNC, 0444); + if (fd < 0) + return -errno; + + return id128_write_fd(fd, f, id, do_sync); +} + +void id128_hash_func(const sd_id128_t *p, struct siphash *state) { + siphash24_compress(p, sizeof(sd_id128_t), state); +} + +int id128_compare_func(const sd_id128_t *a, const sd_id128_t *b) { + return memcmp(a, b, 16); +} + +sd_id128_t id128_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; +} + +DEFINE_HASH_OPS(id128_hash_ops, sd_id128_t, id128_hash_func, id128_compare_func); |