From 85eca92e2061043d733991b386d8dc10fad0fc30 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 22 Oct 2015 18:24:59 +0200 Subject: path-util: rework find_binary(), fsck_exists() and mkfs_exists() Modernize the code a bit: - Get rid of FOREACH_WORD_SEPARATOR() loop in favour of a extract_first_word() loop. - Remove find_binary()'s "local" flag. It's not reasonably possible to look for binaries on remote systems, we hence should not pretend we could. - When we cannot find a suitable binary, return the last error returned from access() rather than ENOENT unconditionally. - Rework fsck_exists() and mkfs_exists() to return 1 on success, 0 if the implementation is missing and negative on real errors. This is more like we do it in other functions. - Make sure we also detect direct fsck symlinks to "true", rather than just absolute ones to /bin/true. --- src/basic/path-util.c | 104 ++++++++++++++++++++++++++++------------------ src/basic/path-util.h | 2 +- src/fsck/fsck.c | 10 ++--- src/run/run.c | 16 ++++--- src/shared/generator.c | 16 +++---- src/test/test-path-util.c | 26 +++++------- 6 files changed, 99 insertions(+), 75 deletions(-) diff --git a/src/basic/path-util.c b/src/basic/path-util.c index 1039623305..9aeb8c23fd 100644 --- a/src/basic/path-util.c +++ b/src/basic/path-util.c @@ -698,7 +698,6 @@ int path_is_os_tree(const char *path) { /* We use /usr/lib/os-release as flag file if something is an OS */ p = strjoina(path, "/usr/lib/os-release"); r = access(p, F_OK); - if (r >= 0) return 1; @@ -709,56 +708,67 @@ int path_is_os_tree(const char *path) { return r >= 0; } -int find_binary(const char *name, bool local, char **filename) { +int find_binary(const char *name, char **ret) { + int last_error, r; + const char *p; + assert(name); if (is_path(name)) { - if (local && access(name, X_OK) < 0) + if (access(name, X_OK) < 0) return -errno; - if (filename) { - char *p; + if (ret) { + char *rs; - p = path_make_absolute_cwd(name); - if (!p) + rs = path_make_absolute_cwd(name); + if (!rs) return -ENOMEM; - *filename = p; + *ret = rs; } return 0; - } else { - const char *path; - const char *word, *state; - size_t l; - - /** - * Plain getenv, not secure_getenv, because we want - * to actually allow the user to pick the binary. - */ - path = getenv("PATH"); - if (!path) - path = DEFAULT_PATH; - - FOREACH_WORD_SEPARATOR(word, l, path, ":", state) { - _cleanup_free_ char *p = NULL; - - if (asprintf(&p, "%.*s/%s", (int) l, word, name) < 0) - return -ENOMEM; + } - if (access(p, X_OK) < 0) - continue; + /** + * Plain getenv, not secure_getenv, because we want + * to actually allow the user to pick the binary. + */ + p = getenv("PATH"); + if (!p) + p = DEFAULT_PATH; + + last_error = -ENOENT; + + for (;;) { + _cleanup_free_ char *j = NULL, *element = NULL; + + r = extract_first_word(&p, &element, ":", EXTRACT_RELAX|EXTRACT_DONT_COALESCE_SEPARATORS); + if (r < 0) + return r; + if (r == 0) + break; + + j = strjoin(element, "/", name, NULL); + if (!j) + return -ENOMEM; + + if (access(j, X_OK) >= 0) { + /* Found it! */ - if (filename) { - *filename = path_kill_slashes(p); - p = NULL; + if (ret) { + *ret = path_kill_slashes(j); + j = NULL; } return 0; } - return -ENOENT; + last_error = -errno; } + + return last_error; } bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) { @@ -800,7 +810,9 @@ static int binary_is_good(const char *binary) { _cleanup_free_ char *p = NULL, *d = NULL; int r; - r = find_binary(binary, true, &p); + r = find_binary(binary, &p); + if (r == -ENOENT) + return 0; if (r < 0) return r; @@ -808,28 +820,38 @@ static int binary_is_good(const char *binary) { * fsck */ r = readlink_malloc(p, &d); - if (r >= 0 && - (path_equal(d, "/bin/true") || - path_equal(d, "/usr/bin/true") || - path_equal(d, "/dev/null"))) - return -ENOENT; + if (r == -EINVAL) /* not a symlink */ + return 1; + if (r < 0) + return r; - return 0; + return !path_equal(d, "true") && + !path_equal(d, "/bin/true") && + !path_equal(d, "/usr/bin/true") && + !path_equal(d, "/dev/null"); } int fsck_exists(const char *fstype) { const char *checker; - checker = strjoina("fsck.", fstype); + assert(fstype); + if (streq(fstype, "auto")) + return -EINVAL; + + checker = strjoina("fsck.", fstype); return binary_is_good(checker); } int mkfs_exists(const char *fstype) { const char *mkfs; - mkfs = strjoina("mkfs.", fstype); + assert(fstype); + if (streq(fstype, "auto")) + return -EINVAL; + + mkfs = strjoina("mkfs.", fstype); return binary_is_good(mkfs); } diff --git a/src/basic/path-util.h b/src/basic/path-util.h index 71e25f1e57..03e1ac5d60 100644 --- a/src/basic/path-util.h +++ b/src/basic/path-util.h @@ -58,7 +58,7 @@ int path_is_mount_point(const char *path, int flags); int path_is_read_only_fs(const char *path); int path_is_os_tree(const char *path); -int find_binary(const char *name, bool local, char **filename); +int find_binary(const char *name, char **filename); bool paths_check_timestamp(const char* const* paths, usec_t *paths_ts_usec, bool update); diff --git a/src/fsck/fsck.c b/src/fsck/fsck.c index 30c846f01d..72a6940849 100644 --- a/src/fsck/fsck.c +++ b/src/fsck/fsck.c @@ -366,12 +366,12 @@ int main(int argc, char *argv[]) { r = sd_device_get_property_value(dev, "ID_FS_TYPE", &type); if (r >= 0) { r = fsck_exists(type); - if (r == -ENOENT) { - log_info("fsck.%s doesn't exist, not checking file system on %s", type, device); - r = 0; + if (r < 0) + log_warning_errno(r, "Couldn't detect if fsck.%s may be used for %s, proceeding: %m", type, device); + else if (r == 0) { + log_info("fsck.%s doesn't exist, not checking file system on %s.", type, device); goto finish; - } else if (r < 0) - log_warning_errno(r, "Couldn't detect if fsck.%s may be used for %s: %m", type, device); + } } if (arg_show_progress) { diff --git a/src/run/run.c b/src/run/run.c index 93d8cd1d08..25ef04a7d2 100644 --- a/src/run/run.c +++ b/src/run/run.c @@ -1153,14 +1153,20 @@ int main(int argc, char* argv[]) { if (r <= 0) goto finish; - if (argc > optind) { - r = find_binary(argv[optind], arg_transport == BUS_TRANSPORT_LOCAL, &command); + if (argc > optind && arg_transport == BUS_TRANSPORT_LOCAL) { + /* Patch in an absolute path */ + + r = find_binary(argv[optind], &command); if (r < 0) { - log_error_errno(r, "Failed to find executable %s%s: %m", - argv[optind], - arg_transport == BUS_TRANSPORT_LOCAL ? "" : " on local system"); + log_error_errno(r, "Failed to find executable %s: %m", argv[optind]); + goto finish; + } + if (r == 0) { + log_error("Couldn't find executable %s.", argv[optind]); + r = -ENOENT; goto finish; } + argv[optind] = command; } diff --git a/src/shared/generator.c b/src/shared/generator.c index e58bbea77c..d912bcd9e1 100644 --- a/src/shared/generator.c +++ b/src/shared/generator.c @@ -32,10 +32,9 @@ #include "dropin.h" static int write_fsck_sysroot_service(const char *dir, const char *what) { - const char *unit; - _cleanup_free_ char *device = NULL; - _cleanup_free_ char *escaped; + _cleanup_free_ char *device = NULL, *escaped = NULL; _cleanup_fclose_ FILE *f = NULL; + const char *unit; int r; escaped = cescape(what); @@ -101,16 +100,17 @@ int generator_write_fsck_deps( if (!isempty(fstype) && !streq(fstype, "auto")) { r = fsck_exists(fstype); - if (r == -ENOENT) { + if (r < 0) + log_warning_errno(r, "Checking was requested for %s, but couldn't detect if fsck.%s may be used, proceeding: %m", what, fstype); + else if (r == 0) { /* treat missing check as essentially OK */ - log_debug_errno(r, "Checking was requested for %s, but fsck.%s does not exist: %m", what, fstype); + log_debug("Checking was requested for %s, but fsck.%s does not exist.", what, fstype); return 0; - } else if (r < 0) - return log_warning_errno(r, "Checking was requested for %s, but fsck.%s cannot be used: %m", what, fstype); + } } if (path_equal(where, "/")) { - char *lnk; + const char *lnk; lnk = strjoina(dir, "/" SPECIAL_LOCAL_FS_TARGET ".wants/systemd-fsck-root.service"); diff --git a/src/test/test-path-util.c b/src/test/test-path-util.c index fce4e81a09..a930196a6c 100644 --- a/src/test/test-path-util.c +++ b/src/test/test-path-util.c @@ -104,32 +104,28 @@ static void test_path(void) { } } -static void test_find_binary(const char *self, bool local) { +static void test_find_binary(const char *self) { char *p; - assert_se(find_binary("/bin/sh", local, &p) == 0); + assert_se(find_binary("/bin/sh", &p) == 0); puts(p); - assert_se(streq(p, "/bin/sh")); + assert_se(path_equal(p, "/bin/sh")); free(p); - assert_se(find_binary(self, local, &p) == 0); + assert_se(find_binary(self, &p) == 0); puts(p); assert_se(endswith(p, "/test-path-util")); assert_se(path_is_absolute(p)); free(p); - assert_se(find_binary("sh", local, &p) == 0); + assert_se(find_binary("sh", &p) == 0); puts(p); assert_se(endswith(p, "/sh")); assert_se(path_is_absolute(p)); free(p); - assert_se(find_binary("xxxx-xxxx", local, &p) == -ENOENT); - - assert_se(find_binary("/some/dir/xxxx-xxxx", local, &p) == - (local ? -ENOENT : 0)); - if (!local) - free(p); + assert_se(find_binary("xxxx-xxxx", &p) == -ENOENT); + assert_se(find_binary("/some/dir/xxxx-xxxx", &p) == -ENOENT); } static void test_prefixes(void) { @@ -210,9 +206,10 @@ static void test_fsck_exists(void) { unsetenv("PATH"); /* fsck.minix is provided by util-linux and will probably exist. */ - assert_se(fsck_exists("minix") == 0); + assert_se(fsck_exists("minix") == 1); - assert_se(fsck_exists("AbCdE") == -ENOENT); + assert_se(fsck_exists("AbCdE") == 0); + assert_se(fsck_exists("/../bin/") == 0); } static void test_make_relative(void) { @@ -450,8 +447,7 @@ static void test_path_is_mount_point(void) { int main(int argc, char **argv) { test_path(); - test_find_binary(argv[0], true); - test_find_binary(argv[0], false); + test_find_binary(argv[0]); test_prefixes(); test_path_join(); test_fsck_exists(); -- cgit v1.2.3-54-g00ecf