From 3b148b365934f5baf2c9162e2454ca416b666531 Mon Sep 17 00:00:00 2001 From: Ray Strode Date: Tue, 9 Aug 2016 10:20:22 -0400 Subject: basic: support default and alternate values for env expansion Sometimes it's useful to provide a default value during an environment expansion, if the environment variable isn't already set. For instance $XDG_DATA_DIRS is suppose to default to: /usr/local/share/:/usr/share/ if it's not yet set. That means callers wishing to augment XDG_DATA_DIRS need to manually add those two values. This commit changes replace_env to support the following shell compatible default value syntax: XDG_DATA_DIRS=/foo:${XDG_DATA_DIRS:-/usr/local/share/:/usr/share} Likewise, it's useful to provide an alternate value during an environment expansion, if the environment variable isn't already set. For instance, $LD_LIBRARY_PATH will inadvertently search the current working directory if it starts or ends with a colon, so the following is usually wrong: LD_LIBRARY_PATH=/foo/lib:${LD_LIBRARY_PATH} To address that, this changes replace_env to support the following shell compatible alternate value syntax: LD_LIBRARY_PATH=/foo/lib${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}} [zj: gate the new syntax under REPLACE_ENV_ALLOW_EXTENDED switch, so existing callers are not modified.] --- src/basic/fileio.c | 127 +++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 88 insertions(+), 39 deletions(-) diff --git a/src/basic/fileio.c b/src/basic/fileio.c index 55dda26a6..5b20fbb49 100644 --- a/src/basic/fileio.c +++ b/src/basic/fileio.c @@ -585,14 +585,9 @@ fail: return r; } -static int parse_env_file_push( +static int check_utf8ness_and_warn( const char *filename, unsigned line, - const char *key, char *value, - void *userdata, - int *n_pushed) { - - const char *k; - va_list aq, *ap = userdata; + const char *key, char *value) { if (!utf8_is_valid(key)) { _cleanup_free_ char *p = NULL; @@ -610,6 +605,23 @@ static int parse_env_file_push( return -EINVAL; } + return 0; +} + +static int parse_env_file_push( + const char *filename, unsigned line, + const char *key, char *value, + void *userdata, + int *n_pushed) { + + const char *k; + va_list aq, *ap = userdata; + int r; + + r = check_utf8ness_and_warn(filename, line, key, value); + if (r < 0) + return r; + va_copy(aq, *ap); while ((k = va_arg(aq, const char *))) { @@ -662,27 +674,19 @@ static int load_env_file_push( char *p; int r; - if (!utf8_is_valid(key)) { - _cleanup_free_ char *t = utf8_escape_invalid(key); - - log_error("%s:%u: invalid UTF-8 for key '%s', ignoring.", strna(filename), line, t); - return -EINVAL; - } - - if (value && !utf8_is_valid(value)) { - _cleanup_free_ char *t = utf8_escape_invalid(value); - - log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, t); - return -EINVAL; - } + r = check_utf8ness_and_warn(filename, line, key, value); + if (r < 0) + return r; - p = strjoin(key, "=", strempty(value), NULL); + p = strjoin(key, "=", value); if (!p) return -ENOMEM; - r = strv_consume(m, p); - if (r < 0) + r = strv_env_replace(m, p); + if (r < 0) { + free(p); return r; + } if (n_pushed) (*n_pushed)++; @@ -716,19 +720,9 @@ static int load_env_file_push_pairs( char ***m = userdata; int r; - if (!utf8_is_valid(key)) { - _cleanup_free_ char *t = utf8_escape_invalid(key); - - log_error("%s:%u: invalid UTF-8 for key '%s', ignoring.", strna(filename), line, t); - return -EINVAL; - } - - if (value && !utf8_is_valid(value)) { - _cleanup_free_ char *t = utf8_escape_invalid(value); - - log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, t); - return -EINVAL; - } + r = check_utf8ness_and_warn(filename, line, key, value); + if (r < 0) + return r; r = strv_extend(m, key); if (r < 0) @@ -778,7 +772,20 @@ static int merge_env_file_push( assert(env); - expanded_value = replace_env(value, *env, REPLACE_ENV_USE_ENVIRONMENT); + if (!value) { + log_error("%s:%u: invalid syntax (around \"%s\"), ignoring.", strna(filename), line, key); + return 0; + } + + if (!env_name_is_valid(key)) { + log_error("%s:%u: invalid variable name \"%s\", ignoring.", strna(filename), line, key); + return 0; + } + + expanded_value = replace_env(value, *env, + REPLACE_ENV_USE_ENVIRONMENT| + REPLACE_ENV_ALLOW_BRACELESS| + REPLACE_ENV_ALLOW_EXTENDED); if (!expanded_value) return -ENOMEM; @@ -792,6 +799,10 @@ int merge_env_file( FILE *f, const char *fname) { + /* NOTE: this function supports braceful and braceless variable expansions, + * plus "extended" substitutions, unlike other exported parsing functions. + */ + return parse_env_file_internal(f, fname, NEWLINE, merge_env_file_push, env, NULL); } @@ -993,9 +1004,9 @@ static int search_and_fopen_internal(const char *path, const char *mode, const c FILE *f; if (root) - p = strjoin(root, *i, "/", path, NULL); + p = strjoin(root, *i, "/", path); else - p = strjoin(*i, "/", path, NULL); + p = strjoin(*i, "/", path); if (!p) return -ENOMEM; @@ -1374,6 +1385,25 @@ int open_tmpfile_linkable(const char *target, int flags, char **ret_path) { return fd; } +int open_serialization_fd(const char *ident) { + int fd = -1; + + fd = memfd_create(ident, MFD_CLOEXEC); + if (fd < 0) { + const char *path; + + path = getpid() == 1 ? "/run/systemd" : "/tmp"; + fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC); + if (fd < 0) + return fd; + + log_debug("Serializing %s to %s.", ident, path); + } else + log_debug("Serializing %s to memfd.", ident); + + return fd; +} + int link_tmpfile(int fd, const char *path, const char *target) { assert(fd >= 0); @@ -1442,3 +1472,22 @@ int read_nul_string(FILE *f, char **ret) { return 0; } + +int mkdtemp_malloc(const char *template, char **ret) { + char *p; + + assert(template); + assert(ret); + + p = strdup(template); + if (!p) + return -ENOMEM; + + if (!mkdtemp(p)) { + free(p); + return -errno; + } + + *ret = p; + return 0; +} -- cgit v1.2.3