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thodg/got/lib/path.c
Stefan Sperling
- lib/path.c
-
/* * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org> * Copyright (c) 2015 Theo de Raadt <deraadt@openbsd.org> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <sys/queue.h> #include <limits.h> #include <stdlib.h> #include <unistd.h> #include <stdio.h> #include <string.h> #include "got_error.h" #include "got_lib_path.h" #ifndef MIN #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b)) #endif int got_path_is_absolute(const char *path) { return path[0] == '/'; } char * got_path_get_absolute(const char *relpath) { char cwd[PATH_MAX]; char *abspath; if (getcwd(cwd, sizeof(cwd)) == NULL) return NULL; if (asprintf(&abspath, "%s/%s/", cwd, relpath) == -1) return NULL; return abspath; } char * got_path_normalize(const char *path) { char *resolved; resolved = realpath(path, NULL); if (resolved == NULL) return NULL; if (!got_path_is_absolute(resolved)) { char *abspath = got_path_get_absolute(resolved); free(resolved); resolved = abspath; } return resolved; } /* based on canonpath() from kern_pledge.c */ const struct got_error * got_canonpath(const char *input, char *buf, size_t bufsize) { const char *p; char *q; /* can't canon relative paths, don't bother */ if (!got_path_is_absolute(input)) { if (strlcpy(buf, input, bufsize) >= bufsize) return got_error(GOT_ERR_NO_SPACE); return NULL; } p = input; q = buf; while (*p && (q - buf < bufsize)) { if (p[0] == '/' && (p[1] == '/' || p[1] == '\0')) { p += 1; } else if (p[0] == '/' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) { p += 2; } else if (p[0] == '/' && p[1] == '.' && p[2] == '.' && (p[3] == '/' || p[3] == '\0')) { p += 3; if (q != buf) /* "/../" at start of buf */ while (*--q != '/') continue; } else { *q++ = *p++; } } if ((*p == '\0') && (q - buf < bufsize)) { *q = 0; return NULL; } else return got_error(GOT_ERR_NO_SPACE); } const struct got_error * got_path_skip_common_ancestor(char **child, const char *parent_abspath, const char *abspath) { const struct got_error *err = NULL; size_t len_parent, len, bufsize; len_parent = strlen(parent_abspath); len = strlen(abspath); if (len_parent >= len) return got_error(GOT_ERR_BAD_PATH); if (strncmp(parent_abspath, abspath, len_parent) != 0) return got_error(GOT_ERR_BAD_PATH); if (abspath[len_parent] != '/') return got_error(GOT_ERR_BAD_PATH); bufsize = len - len_parent + 1; *child = malloc(bufsize); if (*child == NULL) return got_error_from_errno(); if (strlcpy(*child, abspath + len_parent, bufsize) >= bufsize) { err = got_error_from_errno(); free(*child); *child = NULL; return err; } return NULL; } int got_path_is_root_dir(const char *path) { return (path[0] == '/' && path[1] == '\0'); } int got_path_is_child(const char *child, const char *parent, size_t parent_len) { if (parent_len == 0) return 1; if (strncmp(parent, child, parent_len) != 0) return 0; if (child[parent_len] != '/') return 0; return 1; } int got_path_cmp(const char *path1, const char *path2) { size_t len1 = strlen(path1); size_t len2 = strlen(path2); size_t min_len = MIN(len1, len2); size_t i = 0; /* Leading directory separators are insignificant. */ while (path1[0] == '/') path1++; while (path2[0] == '/') path2++; len1 = strlen(path1); len2 = strlen(path2); min_len = MIN(len1, len2); /* Skip over common prefix. */ while (i < min_len && path1[i] == path2[i]) i++; /* Are the paths exactly equal (besides path separators)? */ if (len1 == len2 && i >= min_len) return 0; /* Skip over redundant trailing path seperators. */ while (path1[i] == '/' && path1[i + 1] == '/') path1++; while (path2[i] == '/' && path2[i + 1] == '/') path2++; /* Trailing path separators are insignificant. */ if (path1[i] == '/' && path1[i + 1] == '\0' && path2[i] == '\0') return 0; if (path2[i] == '/' && path2[i + 1] == '\0' && path1[i] == '\0') return 0; /* Order children in subdirectories directly after their parents. */ if (path1[i] == '/' && path2[i] == '\0') return 1; if (path2[i] == '/' && path1[i] == '\0') return -1; if (path1[i] == '/' && path2[i] != '\0') return -1; if (path2[i] == '/' && path1[i] != '\0') return 1; /* Next character following the common prefix determines order. */ return (unsigned char)path1[i] < (unsigned char)path2[i] ? -1 : 1; } const struct got_error * got_pathlist_insert(struct got_pathlist_entry **inserted, struct got_pathlist_head *pathlist, const char *path, void *data) { struct got_pathlist_entry *new, *pe; if (inserted) *inserted = NULL; new = malloc(sizeof(*new)); if (new == NULL) return got_error_from_errno(); new->path = path; new->data = data; /* * Many callers will provide paths in a somewhat sorted order while * constructing a path list from inputs such as tree objects or * dirents. Iterating backwards from the tail of the list should * be more efficient than traversing through the entire list each * time an element is inserted. */ pe = TAILQ_LAST(pathlist, got_pathlist_head); while (pe) { int cmp = got_path_cmp(pe->path, path); if (cmp == 0) { free(new); /* duplicate */ return NULL; } else if (cmp < 0) { TAILQ_INSERT_AFTER(pathlist, pe, new, entry); if (inserted) *inserted = new; return NULL; } pe = TAILQ_PREV(pe, got_pathlist_head, entry); } TAILQ_INSERT_HEAD(pathlist, new, entry); if (inserted) *inserted = new; return NULL; } void got_pathlist_free(struct got_pathlist_head *pathlist) { struct got_pathlist_entry *pe; while ((pe = TAILQ_FIRST(pathlist)) != NULL) { TAILQ_REMOVE(pathlist, pe, entry); free(pe); } }