/*------------------------------------------------------------------------- * * path.c * portable path handling routines * * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/port/path.c * *------------------------------------------------------------------------- */ #ifndef FRONTEND #include "postgres.h" #else #include "postgres_fe.h" #endif #include #include #ifdef WIN32 #ifdef _WIN32_IE #undef _WIN32_IE #endif #define _WIN32_IE 0x0500 #ifdef near #undef near #endif #define near #include #else #include #endif #include "pg_config_paths.h" #ifndef WIN32 #define IS_PATH_VAR_SEP(ch) ((ch) == ':') #else #define IS_PATH_VAR_SEP(ch) ((ch) == ';') #endif static void make_relative_path(char *ret_path, const char *target_path, const char *bin_path, const char *my_exec_path); static void trim_directory(char *path); static void trim_trailing_separator(char *path); /* * skip_drive * * On Windows, a path may begin with "C:" or "//network/". Advance over * this and point to the effective start of the path. */ #ifdef WIN32 static char * skip_drive(const char *path) { if (IS_DIR_SEP(path[0]) && IS_DIR_SEP(path[1])) { path += 2; while (*path && !IS_DIR_SEP(*path)) path++; } else if (isalpha((unsigned char) path[0]) && path[1] == ':') { path += 2; } return (char *) path; } #else #define skip_drive(path) (path) #endif /* * has_drive_prefix * * Return true if the given pathname has a drive prefix. */ bool has_drive_prefix(const char *path) { #ifdef WIN32 return skip_drive(path) != path; #else return false; #endif } /* * first_dir_separator * * Find the location of the first directory separator, return * NULL if not found. */ char * first_dir_separator(const char *filename) { const char *p; for (p = skip_drive(filename); *p; p++) if (IS_DIR_SEP(*p)) return unconstify(char *, p); return NULL; } /* * first_path_var_separator * * Find the location of the first path separator (i.e. ':' on * Unix, ';' on Windows), return NULL if not found. */ char * first_path_var_separator(const char *pathlist) { const char *p; /* skip_drive is not needed */ for (p = pathlist; *p; p++) if (IS_PATH_VAR_SEP(*p)) return unconstify(char *, p); return NULL; } /* * last_dir_separator * * Find the location of the last directory separator, return * NULL if not found. */ char * last_dir_separator(const char *filename) { const char *p, *ret = NULL; for (p = skip_drive(filename); *p; p++) if (IS_DIR_SEP(*p)) ret = p; return unconstify(char *, ret); } /* * make_native_path - on WIN32, change / to \ in the path * * This effectively undoes canonicalize_path. * * This is required because WIN32 COPY is an internal CMD.EXE * command and doesn't process forward slashes in the same way * as external commands. Quoting the first argument to COPY * does not convert forward to backward slashes, but COPY does * properly process quoted forward slashes in the second argument. * * COPY works with quoted forward slashes in the first argument * only if the current directory is the same as the directory * of the first argument. */ void make_native_path(char *filename) { #ifdef WIN32 char *p; for (p = filename; *p; p++) if (*p == '/') *p = '\\'; #endif } /* * This function cleans up the paths for use with either cmd.exe or Msys * on Windows. We need them to use filenames without spaces, for which a * short filename is the safest equivalent, eg: * C:/Progra~1/ */ void cleanup_path(char *path) { #ifdef WIN32 char *ptr; /* * GetShortPathName() will fail if the path does not exist, or short names * are disabled on this file system. In both cases, we just return the * original path. This is particularly useful for --sysconfdir, which * might not exist. */ GetShortPathName(path, path, MAXPGPATH - 1); /* Replace '\' with '/' */ for (ptr = path; *ptr; ptr++) { if (*ptr == '\\') *ptr = '/'; } #endif } /* * join_path_components - join two path components, inserting a slash * * We omit the slash if either given component is empty. * * ret_path is the output area (must be of size MAXPGPATH) * * ret_path can be the same as head, but not the same as tail. */ void join_path_components(char *ret_path, const char *head, const char *tail) { if (ret_path != head) strlcpy(ret_path, head, MAXPGPATH); /* * Remove any leading "." in the tail component. * * Note: we used to try to remove ".." as well, but that's tricky to get * right; now we just leave it to be done by canonicalize_path() later. */ while (tail[0] == '.' && IS_DIR_SEP(tail[1])) tail += 2; if (*tail) { /* only separate with slash if head wasn't empty */ snprintf(ret_path + strlen(ret_path), MAXPGPATH - strlen(ret_path), "%s%s", (*(skip_drive(head)) != '\0') ? "/" : "", tail); } } /* * Clean up path by: * o make Win32 path use Unix slashes * o remove trailing quote on Win32 * o remove trailing slash * o remove duplicate adjacent separators * o remove trailing '.' * o process trailing '..' ourselves */ void canonicalize_path(char *path) { char *p, *to_p; char *spath; bool was_sep = false; int pending_strips; #ifdef WIN32 /* * The Windows command processor will accept suitably quoted paths with * forward slashes, but barfs badly with mixed forward and back slashes. */ for (p = path; *p; p++) { if (*p == '\\') *p = '/'; } /* * In Win32, if you do: prog.exe "a b" "\c\d\" the system will pass \c\d" * as argv[2], so trim off trailing quote. */ if (p > path && *(p - 1) == '"') *(p - 1) = '/'; #endif /* * Removing the trailing slash on a path means we never get ugly double * trailing slashes. Also, Win32 can't stat() a directory with a trailing * slash. Don't remove a leading slash, though. */ trim_trailing_separator(path); /* * Remove duplicate adjacent separators */ p = path; #ifdef WIN32 /* Don't remove leading double-slash on Win32 */ if (*p) p++; #endif to_p = p; for (; *p; p++, to_p++) { /* Handle many adjacent slashes, like "/a///b" */ while (*p == '/' && was_sep) p++; if (to_p != p) *to_p = *p; was_sep = (*p == '/'); } *to_p = '\0'; /* * Remove any trailing uses of "." and process ".." ourselves * * Note that "/../.." should reduce to just "/", while "../.." has to be * kept as-is. In the latter case we put back mistakenly trimmed ".." * components below. Also note that we want a Windows drive spec to be * visible to trim_directory(), but it's not part of the logic that's * looking at the name components; hence distinction between path and * spath. */ spath = skip_drive(path); pending_strips = 0; for (;;) { int len = strlen(spath); if (len >= 2 && strcmp(spath + len - 2, "/.") == 0) trim_directory(path); else if (strcmp(spath, ".") == 0) { /* Want to leave "." alone, but "./.." has to become ".." */ if (pending_strips > 0) *spath = '\0'; break; } else if ((len >= 3 && strcmp(spath + len - 3, "/..") == 0) || strcmp(spath, "..") == 0) { trim_directory(path); pending_strips++; } else if (pending_strips > 0 && *spath != '\0') { /* trim a regular directory name canceled by ".." */ trim_directory(path); pending_strips--; /* foo/.. should become ".", not empty */ if (*spath == '\0') strcpy(spath, "."); } else break; } if (pending_strips > 0) { /* * We could only get here if path is now totally empty (other than a * possible drive specifier on Windows). We have to put back one or * more ".."'s that we took off. */ while (--pending_strips > 0) strcat(path, "../"); strcat(path, ".."); } } /* * Detect whether a path contains any parent-directory references ("..") * * The input *must* have been put through canonicalize_path previously. * * This is a bit tricky because we mustn't be fooled by "..a.." (legal) * nor "C:.." (legal on Unix but not Windows). */ bool path_contains_parent_reference(const char *path) { int path_len; path = skip_drive(path); /* C: shouldn't affect our conclusion */ path_len = strlen(path); /* * ".." could be the whole path; otherwise, if it's present it must be at * the beginning, in the middle, or at the end. */ if (strcmp(path, "..") == 0 || strncmp(path, "../", 3) == 0 || strstr(path, "/../") != NULL || (path_len >= 3 && strcmp(path + path_len - 3, "/..") == 0)) return true; return false; } /* * Detect whether a path is only in or below the current working directory. * An absolute path that matches the current working directory should * return false (we only want relative to the cwd). We don't allow * "/../" even if that would keep us under the cwd (it is too hard to * track that). */ bool path_is_relative_and_below_cwd(const char *path) { if (is_absolute_path(path)) return false; /* don't allow anything above the cwd */ else if (path_contains_parent_reference(path)) return false; #ifdef WIN32 /* * On Win32, a drive letter _not_ followed by a slash, e.g. 'E:abc', is * relative to the cwd on that drive, or the drive's root directory if * that drive has no cwd. Because the path itself cannot tell us which is * the case, we have to assume the worst, i.e. that it is not below the * cwd. We could use GetFullPathName() to find the full path but that * could change if the current directory for the drive changes underneath * us, so we just disallow it. */ else if (isalpha((unsigned char) path[0]) && path[1] == ':' && !IS_DIR_SEP(path[2])) return false; #endif else return true; } /* * Detect whether path1 is a prefix of path2 (including equality). * * This is pretty trivial, but it seems better to export a function than * to export IS_DIR_SEP. */ bool path_is_prefix_of_path(const char *path1, const char *path2) { int path1_len = strlen(path1); if (strncmp(path1, path2, path1_len) == 0 && (IS_DIR_SEP(path2[path1_len]) || path2[path1_len] == '\0')) return true; return false; } /* * Extracts the actual name of the program as called - * stripped of .exe suffix if any */ const char * get_progname(const char *argv0) { const char *nodir_name; char *progname; nodir_name = last_dir_separator(argv0); if (nodir_name) nodir_name++; else nodir_name = skip_drive(argv0); /* * Make a copy in case argv[0] is modified by ps_status. Leaks memory, but * called only once. */ progname = strdup(nodir_name); if (progname == NULL) { fprintf(stderr, "%s: out of memory\n", nodir_name); abort(); /* This could exit the postmaster */ } #if defined(__CYGWIN__) || defined(WIN32) /* strip ".exe" suffix, regardless of case */ if (strlen(progname) > sizeof(EXE) - 1 && pg_strcasecmp(progname + strlen(progname) - (sizeof(EXE) - 1), EXE) == 0) progname[strlen(progname) - (sizeof(EXE) - 1)] = '\0'; #endif return progname; } /* * dir_strcmp: strcmp except any two DIR_SEP characters are considered equal, * and we honor filesystem case insensitivity if known */ static int dir_strcmp(const char *s1, const char *s2) { while (*s1 && *s2) { if ( #ifndef WIN32 *s1 != *s2 #else /* On windows, paths are case-insensitive */ pg_tolower((unsigned char) *s1) != pg_tolower((unsigned char) *s2) #endif && !(IS_DIR_SEP(*s1) && IS_DIR_SEP(*s2))) return (int) *s1 - (int) *s2; s1++, s2++; } if (*s1) return 1; /* s1 longer */ if (*s2) return -1; /* s2 longer */ return 0; } /* * make_relative_path - make a path relative to the actual binary location * * This function exists to support relocation of installation trees. * * ret_path is the output area (must be of size MAXPGPATH) * target_path is the compiled-in path to the directory we want to find * bin_path is the compiled-in path to the directory of executables * my_exec_path is the actual location of my executable * * We determine the common prefix of target_path and bin_path, then compare * the remainder of bin_path to the last directory component(s) of * my_exec_path. If they match, build the result as the part of my_exec_path * preceding the match, joined to the remainder of target_path. If no match, * return target_path as-is. * * For example: * target_path = '/usr/local/share/postgresql' * bin_path = '/usr/local/bin' * my_exec_path = '/opt/pgsql/bin/postmaster' * Given these inputs, the common prefix is '/usr/local/', the tail of * bin_path is 'bin' which does match the last directory component of * my_exec_path, so we would return '/opt/pgsql/share/postgresql' */ static void make_relative_path(char *ret_path, const char *target_path, const char *bin_path, const char *my_exec_path) { int prefix_len; int tail_start; int tail_len; int i; /* * Determine the common prefix --- note we require it to end on a * directory separator, consider eg '/usr/lib' and '/usr/libexec'. */ prefix_len = 0; for (i = 0; target_path[i] && bin_path[i]; i++) { if (IS_DIR_SEP(target_path[i]) && IS_DIR_SEP(bin_path[i])) prefix_len = i + 1; else if (target_path[i] != bin_path[i]) break; } if (prefix_len == 0) goto no_match; /* no common prefix? */ tail_len = strlen(bin_path) - prefix_len; /* * Set up my_exec_path without the actual executable name, and * canonicalize to simplify comparison to bin_path. */ strlcpy(ret_path, my_exec_path, MAXPGPATH); trim_directory(ret_path); /* remove my executable name */ canonicalize_path(ret_path); /* * Tail match? */ tail_start = (int) strlen(ret_path) - tail_len; if (tail_start > 0 && IS_DIR_SEP(ret_path[tail_start - 1]) && dir_strcmp(ret_path + tail_start, bin_path + prefix_len) == 0) { ret_path[tail_start] = '\0'; trim_trailing_separator(ret_path); join_path_components(ret_path, ret_path, target_path + prefix_len); canonicalize_path(ret_path); return; } no_match: strlcpy(ret_path, target_path, MAXPGPATH); canonicalize_path(ret_path); } /* * make_absolute_path * * If the given pathname isn't already absolute, make it so, interpreting * it relative to the current working directory. * * Also canonicalizes the path. The result is always a malloc'd copy. * * In backend, failure cases result in ereport(ERROR); in frontend, * we write a complaint on stderr and return NULL. * * Note: interpretation of relative-path arguments during postmaster startup * should happen before doing ChangeToDataDir(), else the user will probably * not like the results. */ char * make_absolute_path(const char *path) { char *new; /* Returning null for null input is convenient for some callers */ if (path == NULL) return NULL; if (!is_absolute_path(path)) { char *buf; size_t buflen; buflen = MAXPGPATH; for (;;) { buf = malloc(buflen); if (!buf) { #ifndef FRONTEND ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); #else fprintf(stderr, _("out of memory\n")); return NULL; #endif } if (getcwd(buf, buflen)) break; else if (errno == ERANGE) { free(buf); buflen *= 2; continue; } else { int save_errno = errno; free(buf); errno = save_errno; #ifndef FRONTEND elog(ERROR, "could not get current working directory: %m"); #else fprintf(stderr, _("could not get current working directory: %s\n"), strerror(errno)); return NULL; #endif } } new = malloc(strlen(buf) + strlen(path) + 2); if (!new) { free(buf); #ifndef FRONTEND ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); #else fprintf(stderr, _("out of memory\n")); return NULL; #endif } sprintf(new, "%s/%s", buf, path); free(buf); } else { new = strdup(path); if (!new) { #ifndef FRONTEND ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); #else fprintf(stderr, _("out of memory\n")); return NULL; #endif } } /* Make sure punctuation is canonical, too */ canonicalize_path(new); return new; } /* * get_share_path */ void get_share_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, PGSHAREDIR, PGBINDIR, my_exec_path); } /* * get_etc_path */ void get_etc_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, SYSCONFDIR, PGBINDIR, my_exec_path); } /* * get_include_path */ void get_include_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, INCLUDEDIR, PGBINDIR, my_exec_path); } /* * get_pkginclude_path */ void get_pkginclude_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, PKGINCLUDEDIR, PGBINDIR, my_exec_path); } /* * get_includeserver_path */ void get_includeserver_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, INCLUDEDIRSERVER, PGBINDIR, my_exec_path); } /* * get_lib_path */ void get_lib_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, LIBDIR, PGBINDIR, my_exec_path); } /* * get_pkglib_path */ void get_pkglib_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, PKGLIBDIR, PGBINDIR, my_exec_path); } /* * get_locale_path */ void get_locale_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, LOCALEDIR, PGBINDIR, my_exec_path); } /* * get_doc_path */ void get_doc_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, DOCDIR, PGBINDIR, my_exec_path); } /* * get_html_path */ void get_html_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, HTMLDIR, PGBINDIR, my_exec_path); } /* * get_man_path */ void get_man_path(const char *my_exec_path, char *ret_path) { make_relative_path(ret_path, MANDIR, PGBINDIR, my_exec_path); } /* * get_home_path * * On Unix, this actually returns the user's home directory. On Windows * it returns the PostgreSQL-specific application data folder. */ bool get_home_path(char *ret_path) { #ifndef WIN32 char pwdbuf[BUFSIZ]; struct passwd pwdstr; struct passwd *pwd = NULL; (void) pqGetpwuid(geteuid(), &pwdstr, pwdbuf, sizeof(pwdbuf), &pwd); if (pwd == NULL) return false; strlcpy(ret_path, pwd->pw_dir, MAXPGPATH); return true; #else char *tmppath; /* * Note: We use getenv() here because the more modern SHGetFolderPath() * would force the backend to link with shell32.lib, which eats valuable * desktop heap. XXX This function is used only in psql, which already * brings in shell32 via libpq. Moving this function to its own file * would keep it out of the backend, freeing it from this concern. */ tmppath = getenv("APPDATA"); if (!tmppath) return false; snprintf(ret_path, MAXPGPATH, "%s/postgresql", tmppath); return true; #endif } /* * get_parent_directory * * Modify the given string in-place to name the parent directory of the * named file. * * If the input is just a file name with no directory part, the result is * an empty string, not ".". This is appropriate when the next step is * join_path_components(), but might need special handling otherwise. * * Caution: this will not produce desirable results if the string ends * with "..". For most callers this is not a problem since the string * is already known to name a regular file. If in doubt, apply * canonicalize_path() first. */ void get_parent_directory(char *path) { trim_directory(path); } /* * trim_directory * * Trim trailing directory from path, that is, remove any trailing slashes, * the last pathname component, and the slash just ahead of it --- but never * remove a leading slash. */ static void trim_directory(char *path) { char *p; path = skip_drive(path); if (path[0] == '\0') return; /* back up over trailing slash(es) */ for (p = path + strlen(path) - 1; IS_DIR_SEP(*p) && p > path; p--) ; /* back up over directory name */ for (; !IS_DIR_SEP(*p) && p > path; p--) ; /* if multiple slashes before directory name, remove 'em all */ for (; p > path && IS_DIR_SEP(*(p - 1)); p--) ; /* don't erase a leading slash */ if (p == path && IS_DIR_SEP(*p)) p++; *p = '\0'; } /* * trim_trailing_separator * * trim off trailing slashes, but not a leading slash */ static void trim_trailing_separator(char *path) { char *p; path = skip_drive(path); p = path + strlen(path); if (p > path) for (p--; p > path && IS_DIR_SEP(*p); p--) *p = '\0'; }