X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Fpath-util.c;h=2f38c1096b642d1b15cb741016401221066951be;hp=fc42a704b7fd77742da60639333e848452e90d6b;hb=7cb9c51ce81818c200f27de4db4a4076cbe4265b;hpb=2ad8416dd057e7e3185169609ca3006e7649f576 diff --git a/src/shared/path-util.c b/src/shared/path-util.c index fc42a704b..2f38c1096 100644 --- a/src/shared/path-util.c +++ b/src/shared/path-util.c @@ -132,6 +132,96 @@ char *path_make_absolute_cwd(const char *p) { return path_make_absolute(p, cwd); } +int path_make_relative(const char *from_dir, const char *to_path, char **_r) { + char *r, *p; + unsigned n_parents; + size_t to_path_len; + + assert(from_dir); + assert(to_path); + assert(_r); + + /* Strips the common part, and adds ".." elements as necessary. */ + + if (!path_is_absolute(from_dir)) + return -EINVAL; + + if (!path_is_absolute(to_path)) + return -EINVAL; + + /* Skip the common part. */ + for (;;) { + size_t a; + size_t b; + + from_dir += strspn(from_dir, "/"); + to_path += strspn(to_path, "/"); + + if (!*from_dir) { + if (!*to_path) + /* from_dir equals to_path. */ + r = strdup("."); + else + /* from_dir is a parent directory of to_path. */ + r = strdup(to_path); + + if (!r) + return -ENOMEM; + + *_r = r; + return 0; + } + + if (!*to_path) + break; + + a = strcspn(from_dir, "/"); + b = strcspn(to_path, "/"); + + if (a != b) + break; + + if (memcmp(from_dir, to_path, a) != 0) + break; + + from_dir += a; + to_path += b; + } + + /* If we're here, then "from_dir" has one or more elements that need to + * be replaced with "..". */ + + /* Count the number of necessary ".." elements. */ + for (n_parents = 0;;) { + from_dir += strspn(from_dir, "/"); + + if (!*from_dir) + break; + + from_dir += strcspn(from_dir, "/"); + n_parents++; + } + + to_path_len = strlen(to_path); + + r = malloc(n_parents * 3 + to_path_len); + if (!r) + return -ENOMEM; + + for (p = r; n_parents > 0; n_parents--, p += 3) + memcpy(p, "../", 3); + + if (to_path_len > 0) + memcpy(p, to_path, to_path_len); + else + /* "to_path" is a parent directory of "from_dir". Let's remove + * the redundant slash from the end of the result. */ + *(p - 1) = 0; + + *_r = r; + return 0; +} + char **path_strv_make_absolute_cwd(char **l) { char **s; @@ -153,7 +243,7 @@ char **path_strv_make_absolute_cwd(char **l) { return l; } -char **path_strv_canonicalize(char **l) { +char **path_strv_canonicalize_absolute(char **l, const char *prefix) { char **s; unsigned k = 0; bool enomem = false; @@ -167,28 +257,63 @@ char **path_strv_canonicalize(char **l) { STRV_FOREACH(s, l) { char *t, *u; + _cleanup_free_ char *orig = NULL; - t = path_make_absolute_cwd(*s); - free(*s); - *s = NULL; - - if (!t) { - enomem = true; + if (!path_is_absolute(*s)) { + free(*s); continue; } + if (prefix) { + orig = *s; + t = strappend(prefix, orig); + if (!t) { + enomem = true; + continue; + } + } else + t = *s; + errno = 0; u = canonicalize_file_name(t); if (!u) { - if (errno == ENOENT) - u = t; - else { + if (errno == ENOENT) { + if (prefix) { + u = orig; + orig = NULL; + free(t); + } else + u = t; + } else { free(t); - if (errno == ENOMEM || !errno) + if (errno == ENOMEM || errno == 0) enomem = true; continue; } + } else if (prefix) { + char *x; + + free(t); + x = path_startswith(u, prefix); + if (x) { + /* restore the slash if it was lost */ + if (!startswith(x, "/")) + *(--x) = '/'; + + t = strdup(x); + free(u); + if (!t) { + enomem = true; + continue; + } + u = t; + } else { + /* canonicalized path goes outside of + * prefix, keep the original path instead */ + u = orig; + orig = NULL; + } } else free(t); @@ -203,11 +328,12 @@ char **path_strv_canonicalize(char **l) { return l; } -char **path_strv_canonicalize_uniq(char **l) { +char **path_strv_canonicalize_absolute_uniq(char **l, const char *prefix) { + if (strv_isempty(l)) return l; - if (!path_strv_canonicalize(l)) + if (!path_strv_canonicalize_absolute(l, prefix)) return NULL; return strv_uniq(l); @@ -315,11 +441,15 @@ bool path_equal(const char *a, const char *b) { } int path_is_mount_point(const char *t, bool allow_symlink) { - char *parent; - int r; - struct file_handle *h; + + union file_handle_union h = { + .handle.handle_bytes = MAX_HANDLE_SZ + }; + int mount_id, mount_id_parent; + char *parent; struct stat a, b; + int r; /* We are not actually interested in the file handles, but * name_to_handle_at() also passes us the mount ID, hence use @@ -328,12 +458,9 @@ int path_is_mount_point(const char *t, bool allow_symlink) { if (path_equal(t, "/")) return 1; - h = alloca(MAX_HANDLE_SZ); - h->handle_bytes = MAX_HANDLE_SZ; - - r = name_to_handle_at(AT_FDCWD, t, h, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); + r = name_to_handle_at(AT_FDCWD, t, &h.handle, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); if (r < 0) { - if (errno == ENOSYS || errno == ENOTSUP) + if (IN_SET(errno, ENOSYS, EOPNOTSUPP)) /* This kernel or file system does not support * name_to_handle_at(), hence fallback to the * traditional stat() logic */ @@ -349,15 +476,14 @@ int path_is_mount_point(const char *t, bool allow_symlink) { if (r < 0) return r; - h->handle_bytes = MAX_HANDLE_SZ; - r = name_to_handle_at(AT_FDCWD, parent, h, &mount_id_parent, 0); + h.handle.handle_bytes = MAX_HANDLE_SZ; + r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, 0); free(parent); - if (r < 0) { /* The parent can't do name_to_handle_at() but the * directory we are interested in can? If so, it must * be a mount point */ - if (errno == ENOTSUP) + if (errno == EOPNOTSUPP) return 1; return -errno; @@ -384,7 +510,6 @@ fallback: r = lstat(parent, &b); free(parent); - if (r < 0) return -errno; @@ -416,19 +541,21 @@ int path_is_os_tree(const char *path) { int find_binary(const char *name, char **filename) { assert(name); - assert(filename); if (strchr(name, '/')) { - char *p; + if (access(name, X_OK) < 0) + return -errno; + + if (filename) { + char *p; - if (path_is_absolute(name)) - p = strdup(name); - else p = path_make_absolute_cwd(name); - if (!p) - return -ENOMEM; + if (!p) + return -ENOMEM; + + *filename = p; + } - *filename = p; return 0; } else { const char *path; @@ -444,18 +571,18 @@ int find_binary(const char *name, char **filename) { path = DEFAULT_PATH; FOREACH_WORD_SEPARATOR(w, l, path, ":", state) { - char *p; + _cleanup_free_ char *p = NULL; if (asprintf(&p, "%.*s/%s", (int) l, w, name) < 0) return -ENOMEM; - if (access(p, X_OK) < 0) { - free(p); + if (access(p, X_OK) < 0) continue; - } - path_kill_slashes(p); - *filename = p; + if (filename) { + *filename = path_kill_slashes(p); + p = NULL; + } return 0; } @@ -498,3 +625,10 @@ bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool upd return changed; } + +int fsck_exists(const char *fstype) { + const char *checker; + + checker = strappenda("fsck.", fstype); + return find_binary(checker, NULL); +}