core: move specifier expansion out of service.c/socket.c

This monopolizes unit file specifier expansion in load-fragment.c, and removes
it from socket.c + service.c. This way expansion becomes an operation done exclusively at time of loading unit files.

Previously specifiers were resolved for all settings during loading of unit
files with the exception of ExecStart= and friends which were resolved in
socket.c and service.c. With this change the latter is also moved to the
loading of unit files.

Fixes: #3061

3 files changed, 40 insertions, 41 deletions

diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 970eed27c1..c844ec2566 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -579,6 +579,7 @@ int config_parse_exec(
                 void *userdata) {
 
         ExecCommand **e = data;
+        Unit *u = userdata;
         const char *p;
         bool semicolon;
         int r;
@@ -604,7 +605,7 @@ int config_parse_exec(
                 _cleanup_free_ ExecCommand *nce = NULL;
                 _cleanup_strv_free_ char **n = NULL;
                 size_t nlen = 0, nbufsize = 0;
-                char *f;
+                const char *f;
                 int i;
 
                 semicolon = false;
@@ -631,47 +632,47 @@ int config_parse_exec(
                         f++;
                 }
 
-                if (isempty(f)) {
+                r = unit_full_printf(u, f, &path);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers on %s, ignoring: %m", f);
+                        return 0;
+                }
+
+                if (isempty(path)) {
                         /* First word is either "-" or "@" with no command. */
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Empty path in command line, ignoring: \"%s\"", rvalue);
                         return 0;
                 }
-                if (!string_is_safe(f)) {
+                if (!string_is_safe(path)) {
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path contains special characters, ignoring: %s", rvalue);
                         return 0;
                 }
-                if (!path_is_absolute(f)) {
+                if (!path_is_absolute(path)) {
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path is not absolute, ignoring: %s", rvalue);
                         return 0;
                 }
-                if (endswith(f, "/")) {
+                if (endswith(path, "/")) {
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path specifies a directory, ignoring: %s", rvalue);
                         return 0;
                 }
 
-                if (f == firstword) {
-                        path = firstword;
-                        firstword = NULL;
-                } else {
-                        path = strdup(f);
-                        if (!path)
-                                return log_oom();
-                }
-
                 if (!separate_argv0) {
+                        char *w = NULL;
+
                         if (!GREEDY_REALLOC(n, nbufsize, nlen + 2))
                                 return log_oom();
-                        f = strdup(path);
-                        if (!f)
+
+                        w = strdup(path);
+                        if (!w)
                                 return log_oom();
-                        n[nlen++] = f;
+                        n[nlen++] = w;
                         n[nlen] = NULL;
                 }
 
                 path_kill_slashes(path);
 
                 while (!isempty(p)) {
-                        _cleanup_free_ char *word = NULL;
+                        _cleanup_free_ char *word = NULL, *resolved = NULL;
 
                         /* Check explicitly for an unquoted semicolon as
                          * command separator token.  */
@@ -682,18 +683,21 @@ int config_parse_exec(
                                 break;
                         }
 
-                        /* Check for \; explicitly, to not confuse it with \\;
-                         * or "\;" or "\\;" etc.  extract_first_word would
-                         * return the same for all of those.  */
+                        /* Check for \; explicitly, to not confuse it with \\; or "\;" or "\\;" etc.
+                         * extract_first_word() would return the same for all of those.  */
                         if (p[0] == '\\' && p[1] == ';' && (!p[2] || strchr(WHITESPACE, p[2]))) {
+                                char *w;
+
                                 p += 2;
                                 p += strspn(p, WHITESPACE);
+
                                 if (!GREEDY_REALLOC(n, nbufsize, nlen + 2))
                                         return log_oom();
-                                f = strdup(";");
-                                if (!f)
+
+                                w = strdup(";");
+                                if (!w)
                                         return log_oom();
-                                n[nlen++] = f;
+                                n[nlen++] = w;
                                 n[nlen] = NULL;
                                 continue;
                         }
@@ -701,14 +705,20 @@ int config_parse_exec(
                         r = extract_first_word_and_warn(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_CUNESCAPE, unit, filename, line, rvalue);
                         if (r == 0)
                                 break;
-                        else if (r < 0)
+                        if (r < 0)
                                 return 0;
 
+                        r = unit_full_printf(u, word, &resolved);
+                        if (r < 0) {
+                                log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to resolve unit specifiers on %s, ignoring: %m", word);
+                                return 0;
+                        }
+
                         if (!GREEDY_REALLOC(n, nbufsize, nlen + 2))
                                 return log_oom();
-                        n[nlen++] = word;
+                        n[nlen++] = resolved;
                         n[nlen] = NULL;
-                        word = NULL;
+                        resolved = NULL;
                 }
 
                 if (!n || !n[0]) {
diff --git a/src/core/service.c b/src/core/service.c
index c68a7122b6..d5b8decc20 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -49,7 +49,6 @@
 #include "string-util.h"
 #include "strv.h"
 #include "unit-name.h"
-#include "unit-printf.h"
 #include "unit.h"
 #include "utf8.h"
 #include "util.h"
@@ -1205,7 +1204,7 @@ static int service_spawn(
                 ExecFlags flags,
                 pid_t *_pid) {
 
-        _cleanup_strv_free_ char **argv = NULL, **final_env = NULL, **our_env = NULL, **fd_names = NULL;
+        _cleanup_strv_free_ char **final_env = NULL, **our_env = NULL, **fd_names = NULL;
         _cleanup_free_ int *fds = NULL;
         unsigned n_fds = 0, n_env = 0;
         const char *path;
@@ -1263,10 +1262,6 @@ static int service_spawn(
         if (r < 0)
                 return r;
 
-        r = unit_full_printf_strv(UNIT(s), c->argv, &argv);
-        if (r < 0)
-                return r;
-
         our_env = new0(char*, 9);
         if (!our_env)
                 return -ENOMEM;
@@ -1349,7 +1344,7 @@ static int service_spawn(
         } else
                 path = UNIT(s)->cgroup_path;
 
-        exec_params.argv = argv;
+        exec_params.argv = c->argv;
         exec_params.environment = final_env;
         exec_params.fds = fds;
         exec_params.fd_names = fd_names;
diff --git a/src/core/socket.c b/src/core/socket.c
index 1a53d47f21..fee9b702e6 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -54,7 +54,6 @@
 #include "string-util.h"
 #include "strv.h"
 #include "unit-name.h"
-#include "unit-printf.h"
 #include "unit.h"
 #include "user-util.h"
 #include "in-addr-util.h"
@@ -1740,7 +1739,6 @@ static int socket_coldplug(Unit *u) {
 }
 
 static int socket_spawn(Socket *s, ExecCommand *c, pid_t *_pid) {
-        _cleanup_free_ char **argv = NULL;
         pid_t pid;
         int r;
         ExecParameters exec_params = {
@@ -1772,11 +1770,7 @@ static int socket_spawn(Socket *s, ExecCommand *c, pid_t *_pid) {
         if (r < 0)
                 return r;
 
-        r = unit_full_printf_strv(UNIT(s), c->argv, &argv);
-        if (r < 0)
-                return r;
-
-        exec_params.argv = argv;
+        exec_params.argv = c->argv;
         exec_params.environment = UNIT(s)->manager->environment;
         exec_params.confirm_spawn = manager_get_confirm_spawn(UNIT(s)->manager);
         exec_params.cgroup_supported = UNIT(s)->manager->cgroup_supported;