diff options
Diffstat (limited to 'src/shared/udev-util.c')
| -rw-r--r-- | src/shared/udev-util.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/shared/udev-util.c b/src/shared/udev-util.c index 411b1f704b..df08e3a40e 100644 --- a/src/shared/udev-util.c +++ b/src/shared/udev-util.c @@ -1,12 +1,16 @@ /* SPDX-License-Identifier: LGPL-2.1-or-later */ +#include <ctype.h> #include <errno.h> +#include <sys/inotify.h> #include <unistd.h> #include "alloc-util.h" +#include "device-nodes.h" #include "device-util.h" #include "env-file.h" #include "escape.h" +#include "fd-util.h" #include "log.h" #include "macro.h" #include "parse-util.h" @@ -14,6 +18,7 @@ #include "signal-util.h" #include "string-table.h" #include "string-util.h" +#include "strxcpyx.h" #include "udev-util.h" #include "utf8.h" @@ -383,3 +388,171 @@ int udev_rule_parse_value(char *str, char **ret_value, char **ret_endpos) { *ret_endpos = i + 1; return 0; } + +size_t udev_replace_whitespace(const char *str, char *to, size_t len) { + bool is_space = false; + size_t i, j; + + assert(str); + assert(to); + + /* Copy from 'str' to 'to', while removing all leading and trailing whitespace, and replacing + * each run of consecutive whitespace with a single underscore. The chars from 'str' are copied + * up to the \0 at the end of the string, or at most 'len' chars. This appends \0 to 'to', at + * the end of the copied characters. + * + * If 'len' chars are copied into 'to', the final \0 is placed at len+1 (i.e. 'to[len] = \0'), + * so the 'to' buffer must have at least len+1 chars available. + * + * Note this may be called with 'str' == 'to', i.e. to replace whitespace in-place in a buffer. + * This function can handle that situation. + * + * Note that only 'len' characters are read from 'str'. */ + + i = strspn(str, WHITESPACE); + + for (j = 0; j < len && i < len && str[i] != '\0'; i++) { + if (isspace(str[i])) { + is_space = true; + continue; + } + + if (is_space) { + if (j + 1 >= len) + break; + + to[j++] = '_'; + is_space = false; + } + to[j++] = str[i]; + } + + to[j] = '\0'; + return j; +} + +size_t udev_replace_chars(char *str, const char *allow) { + size_t i = 0, replaced = 0; + + assert(str); + + /* allow chars in allow list, plain ascii, hex-escaping and valid utf8. */ + + while (str[i] != '\0') { + int len; + + if (allow_listed_char_for_devnode(str[i], allow)) { + i++; + continue; + } + + /* accept hex encoding */ + if (str[i] == '\\' && str[i+1] == 'x') { + i += 2; + continue; + } + + /* accept valid utf8 */ + len = utf8_encoded_valid_unichar(str + i, (size_t) -1); + if (len > 1) { + i += len; + continue; + } + + /* if space is allowed, replace whitespace with ordinary space */ + if (isspace(str[i]) && allow && strchr(allow, ' ')) { + str[i] = ' '; + i++; + replaced++; + continue; + } + + /* everything else is replaced with '_' */ + str[i] = '_'; + i++; + replaced++; + } + return replaced; +} + +int udev_resolve_subsys_kernel(const char *string, char *result, size_t maxsize, bool read_value) { + _cleanup_(sd_device_unrefp) sd_device *dev = NULL; + _cleanup_free_ char *temp = NULL; + char *subsys, *sysname, *attr; + const char *val; + int r; + + assert(string); + assert(result); + + /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */ + + if (string[0] != '[') + return -EINVAL; + + temp = strdup(string); + if (!temp) + return -ENOMEM; + + subsys = &temp[1]; + + sysname = strchr(subsys, '/'); + if (!sysname) + return -EINVAL; + sysname[0] = '\0'; + sysname = &sysname[1]; + + attr = strchr(sysname, ']'); + if (!attr) + return -EINVAL; + attr[0] = '\0'; + attr = &attr[1]; + if (attr[0] == '/') + attr = &attr[1]; + if (attr[0] == '\0') + attr = NULL; + + if (read_value && !attr) + return -EINVAL; + + r = sd_device_new_from_subsystem_sysname(&dev, subsys, sysname); + if (r < 0) + return r; + + if (read_value) { + r = sd_device_get_sysattr_value(dev, attr, &val); + if (r < 0 && r != -ENOENT) + return r; + if (r == -ENOENT) + result[0] = '\0'; + else + strscpy(result, maxsize, val); + log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result); + } else { + r = sd_device_get_syspath(dev, &val); + if (r < 0) + return r; + + strscpyl(result, maxsize, val, attr ? "/" : NULL, attr ?: NULL, NULL); + log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, strempty(attr), result); + } + return 0; +} + +int udev_queue_is_empty(void) { + return access("/run/udev/queue", F_OK) < 0 ? + (errno == ENOENT ? true : -errno) : false; +} + +int udev_queue_init(void) { + _cleanup_close_ int fd = -1; + + fd = inotify_init1(IN_CLOEXEC); + if (fd < 0) + return -errno; + + if (inotify_add_watch(fd, "/run/udev" , IN_DELETE) < 0) + return -errno; + + return TAKE_FD(fd); +} |