From 6172788a3f90962b42564b5248f540b4cb729470 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Sun, 9 Jul 2017 23:31:47 -0400
Subject: [PATCH] cryptsetup-generator: add a helper utility to create symlinks

It seems that there's a common pattern among the various generators. Let's add
a helper function for it and make use of it in cryptsetup-generator.

This fixes a bunch of theoretical memleaks in error paths, since *to wasn't
generally freed properly. Not thath it matters.

(cherry picked from commit b559616f2321643c5194b474d39a722cefaf6059)
(cherry picked from commit ea8cb69ee23cd67ef45ca34f1b192c9adb5fa878)
---
 src/cryptsetup/cryptsetup-generator.c | 53 ++++++++++-------------------------
 src/shared/generator.c                | 15 ++++++++++
 src/shared/generator.h                |  2 ++
 3 files changed, 32 insertions(+), 38 deletions(-)

diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c
index f737f82b55..f10e9fdc24 100644
--- a/src/cryptsetup/cryptsetup-generator.c
+++ b/src/cryptsetup/cryptsetup-generator.c
@@ -58,11 +58,11 @@ static int create_disk(
                 const char *password,
                 const char *options) {
 
-        _cleanup_free_ char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *to = NULL, *e = NULL,
+        _cleanup_free_ char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *e = NULL,
                 *filtered = NULL;
         _cleanup_fclose_ FILE *f = NULL;
+        const char *dmname;
         bool noauto, nofail, tmp, swap;
-        char *from;
         int r;
 
         assert(name);
@@ -120,7 +120,7 @@ static int create_disk(
         if (password) {
                 if (STR_IN_SET(password, "/dev/urandom", "/dev/random", "/dev/hw_random"))
                         fputs("After=systemd-random-seed.service\n", f);
-                else if (!streq(password, "-") && !streq(password, "none")) {
+                else if (!STR_IN_SET(password, "-", "none")) {
                         _cleanup_free_ char *uu;
 
                         uu = fstab_node_to_udev_node(password);
@@ -186,46 +186,23 @@ static int create_disk(
         if (r < 0)
                 return log_error_errno(r, "Failed to write file %s: %m", p);
 
-        from = strjoina("../", n);
-
         if (!noauto) {
-
-                to = strjoin(arg_dest, "/", d, ".wants/", n);
-                if (!to)
-                        return log_oom();
-
-                mkdir_parents_label(to, 0755);
-                if (symlink(from, to) < 0)
-                        return log_error_errno(errno, "Failed to create symlink %s: %m", to);
-
-                free(to);
-                if (!nofail)
-                        to = strjoin(arg_dest, "/cryptsetup.target.requires/", n);
-                else
-                        to = strjoin(arg_dest, "/cryptsetup.target.wants/", n);
-                if (!to)
-                        return log_oom();
-
-                mkdir_parents_label(to, 0755);
-                if (symlink(from, to) < 0)
-                        return log_error_errno(errno, "Failed to create symlink %s: %m", to);
+                r = generator_add_symlink(arg_dest, d, "wants", n);
+                if (r < 0)
+                        return r;
+
+                r = generator_add_symlink(arg_dest, "cryptsetup.target",
+                                          nofail ? "wants" : "requires", n);
+                if (r < 0)
+                        return r;
         }
 
-        free(to);
-        to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n);
-        if (!to)
-                return log_oom();
-
-        mkdir_parents_label(to, 0755);
-        if (symlink(from, to) < 0)
-                return log_error_errno(errno, "Failed to create symlink %s: %m", to);
+        dmname = strjoina("dev-mapper-", e, ".device");
+        r = generator_add_symlink(arg_dest, dmname, "requires", n);
+        if (r < 0)
+                return r;
 
         if (!noauto && !nofail) {
-                _cleanup_free_ char *dmname;
-                dmname = strjoin("dev-mapper-", e, ".device");
-                if (!dmname)
-                        return log_oom();
-
                 r = write_drop_in(arg_dest, dmname, 90, "device-timeout",
                                   "# Automatically generated by systemd-cryptsetup-generator \n\n"
                                   "[Unit]\nJobTimeoutSec=0");
diff --git a/src/shared/generator.c b/src/shared/generator.c
index 9a069b2f97..c01e9cb519 100644
--- a/src/shared/generator.c
+++ b/src/shared/generator.c
@@ -37,6 +37,21 @@
 #include "unit-name.h"
 #include "util.h"
 
+int generator_add_symlink(const char *root, const char *dst, const char *dep_type, const char *src) {
+        /* Adds a symlink from <dst>.<dep_type>.d/ to ../<src> */
+
+        const char *from, *to;
+
+        from = strjoina("../", src);
+        to = strjoina(root, "/", dst, ".", dep_type, "/", src);
+
+        mkdir_parents_label(to, 0755);
+        if (symlink(from, to) < 0)
+                return log_error_errno(errno, "Failed to create symlink \"%s\": %m", to);
+
+        return 0;
+}
+
 static int write_fsck_sysroot_service(const char *dir, const char *what) {
         _cleanup_free_ char *device = NULL, *escaped = NULL;
         _cleanup_fclose_ FILE *f = NULL;
diff --git a/src/shared/generator.h b/src/shared/generator.h
index a6017c1b76..7bafda03f2 100644
--- a/src/shared/generator.h
+++ b/src/shared/generator.h
@@ -21,6 +21,8 @@
 
 #include <stdio.h>
 
+int generator_add_symlink(const char *root, const char *dst, const char *dep_type, const char *src);
+
 int generator_write_fsck_deps(
         FILE *f,
         const char *dir,