path: add new "systemd-path" utility for querying paths described in file-hierarchy(7)

This new tool is based on "sd-path", a new (so far unexported) API for
libsystemd, that can hopefully grow into a workable API covering /opt
and more one day.

2 files changed, 627 insertions, 0 deletions

diff --git a/src/libsystemd/sd-path/Makefile b/src/libsystemd/sd-path/Makefile
new file mode 120000
index 0000000000..d0b0e8e008
--- /dev/null
+++ b/src/libsystemd/sd-path/Makefile
@@ -0,0 +1 @@
+../Makefile
\ No newline at end of file
diff --git a/src/libsystemd/sd-path/sd-path.c b/src/libsystemd/sd-path/sd-path.c
new file mode 100644
index 0000000000..44c1b8bd70
--- /dev/null
+++ b/src/libsystemd/sd-path/sd-path.c
@@ -0,0 +1,626 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2014 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 "util.h"
+#include "architecture.h"
+#include "path-util.h"
+#include "strv.h"
+#include "sd-path.h"
+
+static int from_environment(const char *envname, const char *fallback, const char **ret) {
+        assert(ret);
+
+        if (envname) {
+                const char *e;
+
+                e = secure_getenv(envname);
+                if (e && path_is_absolute(e)) {
+                        *ret = e;
+                        return 0;
+                }
+        }
+
+        if (fallback) {
+                *ret = fallback;
+                return 0;
+        }
+
+        return -ENXIO;
+}
+
+static int from_home_dir(const char *envname, const char *suffix, char **buffer, const char **ret) {
+        _cleanup_free_ char *h = NULL;
+        char *cc = NULL;
+        int r;
+
+        assert(suffix);
+        assert(buffer);
+        assert(ret);
+
+        if (envname) {
+                const char *e = NULL;
+
+                e = secure_getenv(envname);
+                if (e && path_is_absolute(e)) {
+                        *ret = e;
+                        return 0;
+                }
+        }
+
+        r = get_home_dir(&h);
+        if (r < 0)
+                return r;
+
+        if (endswith(h, "/"))
+                cc = strappend(h, suffix);
+        else
+                cc = strjoin(h, "/", suffix, NULL);
+        if (!cc)
+                return -ENOMEM;
+
+        *buffer = cc;
+        *ret = cc;
+        return 0;
+}
+
+static int from_user_dir(const char *field, char **buffer, const char **ret) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *b = NULL;
+        const char *fn = NULL;
+        char line[LINE_MAX];
+        size_t n;
+        int r;
+
+        assert(field);
+        assert(buffer);
+        assert(ret);
+
+        r = from_home_dir(NULL, ".config/user-dirs.dirs", &b, &fn);
+        if (r < 0)
+                return r;
+
+        f = fopen(fn, "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        goto fallback;
+
+                return -errno;
+        }
+
+        /* This is an awful parse, but it follows closely what
+         * xdg-user-dirs does upstream */
+
+        n = strlen(field);
+        FOREACH_LINE(line, f, return -errno) {
+                char *l, *p, *e;
+
+                l = strstrip(line);
+
+                if (!strneq(l, field, n))
+                        continue;
+
+                p = l + n;
+                p += strspn(p, WHITESPACE);
+
+                if (*p != '=')
+                        continue;
+                p++;
+
+                p += strspn(p, WHITESPACE);
+
+                if (*p != '"')
+                        continue;
+                p++;
+
+                e = strrchr(p, '"');
+                if (!e)
+                        continue;
+                *e = 0;
+
+                /* Three syntaxes permitted: relative to $HOME, $HOME itself, and absolute path */
+                if (startswith(p, "$HOME/")) {
+                        _cleanup_free_ char *h = NULL;
+                        char *cc;
+
+                        r = get_home_dir(&h);
+                        if (r < 0)
+                                return r;
+
+                        cc = strappend(h, p+5);
+                        if (!cc)
+                                return -ENOMEM;
+
+                        *buffer = cc;
+                        *ret = cc;
+                        return 0;
+                } else if (streq(p, "$HOME")) {
+
+                        r = get_home_dir(buffer);
+                        if (r < 0)
+                                return r;
+
+                        *ret = *buffer;
+                        return 0;
+                } else if (path_is_absolute(p)) {
+                        char *copy;
+
+                        copy = strdup(p);
+                        if (!copy)
+                                return -ENOMEM;
+
+                        *buffer = copy;
+                        *ret = copy;
+                        return 0;
+                }
+        }
+
+fallback:
+        /* The desktop directory defaults to $HOME/Desktop, the others to $HOME */
+        if (streq(field, "XDG_DESKTOP_DIR")) {
+                _cleanup_free_ char *h = NULL;
+                char *cc;
+
+                r = get_home_dir(&h);
+                if (r < 0)
+                        return r;
+
+                cc = strappend(h, "/Desktop");
+                if (!cc)
+                        return -ENOMEM;
+
+                *buffer = cc;
+                *ret = cc;
+        } else {
+
+                r = get_home_dir(buffer);
+                if (r < 0)
+                        return r;
+
+                *ret = *buffer;
+        }
+
+        return 0;
+}
+
+static int get_path(uint64_t type, char **buffer, const char **ret) {
+        int r;
+
+        assert(buffer);
+        assert(ret);
+
+        switch (type) {
+
+        case SD_PATH_TEMPORARY:
+                return from_environment("TMPDIR", "/tmp", ret);
+
+        case SD_PATH_TEMPORARY_LARGE:
+                return from_environment("TMPDIR", "/var/tmp", ret);
+
+        case SD_PATH_SYSTEM_BINARIES:
+                *ret = "/usr/bin";
+                return 0;
+
+        case SD_PATH_SYSTEM_INCLUDE:
+                *ret = "/usr/include";
+                return 0;
+
+        case SD_PATH_SYSTEM_LIBRARY_PRIVATE:
+                *ret = "/usr/lib";
+                return 0;
+
+        case SD_PATH_SYSTEM_LIBRARY_ARCH:
+                *ret = LIBDIR;
+                return 0;
+
+        case SD_PATH_SYSTEM_SHARED:
+                *ret = "/usr/share";
+                return 0;
+
+        case SD_PATH_SYSTEM_CONFIGURATION_FACTORY:
+                *ret = "/usr/share/factory/etc";
+                return 0;
+
+        case SD_PATH_SYSTEM_STATE_FACTORY:
+                *ret = "/usr/share/factory/var";
+                return 0;
+
+        case SD_PATH_SYSTEM_CONFIGURATION:
+                *ret = "/etc";
+                return 0;
+
+        case SD_PATH_SYSTEM_RUNTIME:
+                *ret = "/run";
+                return 0;
+
+        case SD_PATH_SYSTEM_RUNTIME_LOGS:
+                *ret = "/run/log";
+                return 0;
+
+        case SD_PATH_SYSTEM_STATE_PRIVATE:
+                *ret = "/var/lib";
+                return 0;
+
+        case SD_PATH_SYSTEM_STATE_LOGS:
+                *ret = "/var/log";
+                return 0;
+
+        case SD_PATH_SYSTEM_STATE_CACHE:
+                *ret = "/var/cache";
+                return 0;
+
+        case SD_PATH_SYSTEM_STATE_SPOOL:
+                *ret = "/var/spool";
+                return 0;
+
+        case SD_PATH_USER_BINARIES:
+                return from_home_dir(NULL, ".local/bin", buffer, ret);
+
+        case SD_PATH_USER_LIBRARY_PRIVATE:
+                return from_home_dir(NULL, ".local/lib", buffer, ret);
+
+        case SD_PATH_USER_LIBRARY_ARCH:
+                return from_home_dir(NULL, ".local/lib/" ARCH_TUPLE, buffer, ret);
+
+        case SD_PATH_USER_SHARED:
+                return from_home_dir("XDG_DATA_HOME", ".local/share", buffer, ret);
+
+        case SD_PATH_USER_CONFIGURATION:
+                return from_home_dir("XDG_CONFIG_HOME", ".config", buffer, ret);
+
+        case SD_PATH_USER_RUNTIME:
+                return from_environment("XDG_RUNTIME_DIR", NULL, ret);
+
+        case SD_PATH_USER_STATE_CACHE:
+                return from_home_dir("XDG_CACHE_HOME", ".cache", buffer, ret);
+
+        case SD_PATH_USER:
+                r = get_home_dir(buffer);
+                if (r < 0)
+                        return r;
+
+                *ret = *buffer;
+                return 0;
+
+        case SD_PATH_USER_DOCUMENTS:
+                return from_user_dir("XDG_DOCUMENTS_DIR", buffer, ret);
+
+        case SD_PATH_USER_MUSIC:
+                return from_user_dir("XDG_MUSIC_DIR", buffer, ret);
+
+        case SD_PATH_USER_PICTURES:
+                return from_user_dir("XDG_PICTURES_DIR", buffer, ret);
+
+        case SD_PATH_USER_VIDEOS:
+                return from_user_dir("XDG_VIDEOS_DIR", buffer, ret);
+
+        case SD_PATH_USER_DOWNLOAD:
+                return from_user_dir("XDG_DOWNLOAD_DIR", buffer, ret);
+
+        case SD_PATH_USER_PUBLIC:
+                return from_user_dir("XDG_PUBLICSHARE_DIR", buffer, ret);
+
+        case SD_PATH_USER_TEMPLATES:
+                return from_user_dir("XDG_TEMPLATES_DIR", buffer, ret);
+
+        case SD_PATH_USER_DESKTOP:
+                return from_user_dir("XDG_DESKTOP_DIR", buffer, ret);
+        }
+
+        return -ENOTSUP;
+}
+
+int sd_path_home(uint64_t type, const char *suffix, char **path) {
+        char *buffer = NULL, *cc;
+        const char *ret;
+        int r;
+
+        assert_return(path, -EINVAL);
+
+        if (IN_SET(type,
+                   SD_PATH_SEARCH_BINARIES,
+                   SD_PATH_SEARCH_LIBRARY_PRIVATE,
+                   SD_PATH_SEARCH_LIBRARY_ARCH,
+                   SD_PATH_SEARCH_SHARED,
+                   SD_PATH_SEARCH_CONFIGURATION_FACTORY,
+                   SD_PATH_SEARCH_STATE_FACTORY,
+                   SD_PATH_SEARCH_CONFIGURATION)) {
+
+                _cleanup_strv_free_ char **l = NULL;
+
+                r = sd_path_search(type, suffix, &l);
+                if (r < 0)
+                        return r;
+
+                buffer = strv_join(l, ":");
+                if (!buffer)
+                        return -ENOMEM;
+
+                *path = buffer;
+                return 0;
+        }
+
+        r = get_path(type, &buffer, &ret);
+        if (r < 0)
+                return r;
+
+        if (!suffix) {
+                if (!buffer) {
+                        buffer = strdup(ret);
+                        if (!buffer)
+                                return -ENOMEM;
+                }
+
+                *path = buffer;
+                return 0;
+        }
+
+        suffix += strspn(suffix, "/");
+
+        if (endswith(ret, "/"))
+                cc = strappend(ret, suffix);
+        else
+                cc = strjoin(ret, "/", suffix, NULL);
+
+        free(buffer);
+
+        if (!cc)
+                return -ENOMEM;
+
+        *path = cc;
+        return 0;
+}
+
+static int search_from_environment(
+                char ***list,
+                const char *env_home,
+                const char *home_suffix,
+                const char *env_search,
+                bool env_search_sufficient,
+                const char *first, ...) {
+
+        const char *e;
+        char *h = NULL;
+        char **l = NULL;
+        int r;
+
+        assert(list);
+
+        if (env_search) {
+                e = secure_getenv(env_search);
+                if (e) {
+                        l = strv_split(e, ":");
+                        if (!l)
+                                return -ENOMEM;
+
+                        if (env_search_sufficient) {
+                                *list = l;
+                                return 0;
+                        }
+                }
+        }
+
+        if (!l && first) {
+                va_list ap;
+
+                va_start(ap, first);
+                l = strv_new_ap(first, ap);
+                va_end(ap);
+
+                if (!l)
+                        return -ENOMEM;
+        }
+
+        if (env_home) {
+                e = secure_getenv(env_home);
+                if (e && path_is_absolute(e)) {
+                        h = strdup(e);
+                        if (!h) {
+                                strv_free(l);
+                                return -ENOMEM;
+                        }
+                }
+        }
+
+        if (!h && home_suffix) {
+                e = secure_getenv("HOME");
+                if (e && path_is_absolute(e)) {
+                        if (endswith(e, "/"))
+                                h = strappend(e, home_suffix);
+                        else
+                                h = strjoin(e, "/", home_suffix, NULL);
+
+                        if (!h) {
+                                strv_free(l);
+                                return -ENOMEM;
+                        }
+                }
+        }
+
+        if (h) {
+                r = strv_consume_prepend(&l, h);
+                if (r < 0) {
+                        strv_free(l);
+                        return -ENOMEM;
+                }
+        }
+
+        *list = l;
+        return 0;
+}
+
+static int get_search(uint64_t type, char ***list) {
+
+        assert(list);
+
+        switch(type) {
+
+        case SD_PATH_SEARCH_BINARIES:
+                return search_from_environment(list,
+                                               NULL,
+                                               ".local/bin",
+                                               "PATH",
+                                               true,
+                                               "/usr/local/sbin",
+                                               "/usr/local/bin",
+                                               "/usr/sbin",
+                                               "/usr/bin",
+#ifdef HAVE_SPLIT_USR
+                                               "/sbin",
+                                               "/bin",
+#endif
+                                               NULL);
+
+        case SD_PATH_SEARCH_LIBRARY_PRIVATE:
+                return search_from_environment(list,
+                                               NULL,
+                                               ".local/lib",
+                                               NULL,
+                                               false,
+                                               "/usr/local/lib",
+                                               "/usr/lib",
+#ifdef HAVE_SPLIT_USR
+                                               "/lib",
+#endif
+                                               NULL);
+
+        case SD_PATH_SEARCH_LIBRARY_ARCH:
+                return search_from_environment(list,
+                                               NULL,
+                                               ".local/lib/" ARCH_TUPLE,
+                                               "LD_LIBRARY_PATH",
+                                               true,
+                                               LIBDIR,
+#ifdef HAVE_SPLIT_USR
+                                               ROOTLIBDIR,
+#endif
+                                               NULL);
+
+        case SD_PATH_SEARCH_SHARED:
+                return search_from_environment(list,
+                                               "XDG_DATA_HOME",
+                                               ".local/share",
+                                               "XDG_DATA_DIRS",
+                                               false,
+                                               "/usr/local/share",
+                                               "/usr/share",
+                                               NULL);
+
+        case SD_PATH_SEARCH_CONFIGURATION_FACTORY:
+                return search_from_environment(list,
+                                               NULL,
+                                               NULL,
+                                               NULL,
+                                               false,
+                                               "/usr/local/share/factory/etc",
+                                               "/usr/share/factory/etc",
+                                               NULL);
+
+        case SD_PATH_SEARCH_STATE_FACTORY:
+                return search_from_environment(list,
+                                               NULL,
+                                               NULL,
+                                               NULL,
+                                               false,
+                                               "/usr/local/share/factory/var",
+                                               "/usr/share/factory/var",
+                                               NULL);
+
+        case SD_PATH_SEARCH_CONFIGURATION:
+                return search_from_environment(list,
+                                               "XDG_CONFIG_HOME",
+                                               ".config",
+                                               "XDG_CONFIG_DIRS",
+                                               false,
+                                               "/etc",
+                                               NULL);
+        }
+
+        return -ENOTSUP;
+}
+
+int sd_path_search(uint64_t type, const char *suffix, char ***paths) {
+        char **l, **i, **j, **n;
+        int r;
+
+        assert_return(paths, -EINVAL);
+
+        if (!IN_SET(type,
+                    SD_PATH_SEARCH_BINARIES,
+                    SD_PATH_SEARCH_LIBRARY_PRIVATE,
+                    SD_PATH_SEARCH_LIBRARY_ARCH,
+                    SD_PATH_SEARCH_SHARED,
+                    SD_PATH_SEARCH_CONFIGURATION_FACTORY,
+                    SD_PATH_SEARCH_STATE_FACTORY,
+                    SD_PATH_SEARCH_CONFIGURATION)) {
+
+                char *p;
+
+                r = sd_path_home(type, suffix, &p);
+                if (r < 0)
+                        return r;
+
+                l = new(char*, 2);
+                if (!l) {
+                        free(p);
+                        return -ENOMEM;
+                }
+
+                l[0] = p;
+                l[1] = NULL;
+
+                *paths = l;
+                return 0;
+        }
+
+        r = get_search(type, &l);
+        if (r < 0)
+                return r;
+
+        if (!suffix) {
+                *paths = l;
+                return 0;
+        }
+
+        n = new(char*, strv_length(l)+1);
+        if (!n) {
+                strv_free(l);
+                return -ENOMEM;
+        }
+
+        j = n;
+        STRV_FOREACH(i, l) {
+
+                if (endswith(*i, "/"))
+                        *j = strappend(*i, suffix);
+                else
+                        *j = strjoin(*i, "/", suffix, NULL);
+
+                if (!*j) {
+                        strv_free(l);
+                        strv_free(n);
+                        return -ENOMEM;
+                }
+
+                j++;
+        }
+
+        *j = NULL;
+        *paths = n;
+        return 0;
+}