diff options
Diffstat (limited to 'src/libsystemd/sd-id128/id128-util.c')
| -rw-r--r-- | src/libsystemd/sd-id128/id128-util.c | 194 |
1 files changed, 194 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 0000000000..c3f527d657 --- /dev/null +++ b/src/libsystemd/sd-id128/id128-util.c @@ -0,0 +1,194 @@ +/*** + 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 <unistd.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 + * 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 33: /* plain UUID with trailing newline */ + if (buffer[32] != '\n') + return -EINVAL; + + /* fall through */ + 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; + + /* fall through */ + case 36: /* RFC UUID without trailing newline */ + if (f == ID128_PLAIN) + 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; + } + + return r; +} + +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, 0444); + if (fd < 0) + return -errno; + + return id128_write_fd(fd, f, id, do_sync); +} |