[PATCH 2/6] qga: Move command execution code to a separate function

[Alexander Ivanov <alexander.ivanov@virtuozzo.com>]

In qmp_guest_set_user_password() we have a part of code that we can reuse
in the future commits. Move this code to a separate function.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
 qga/commands-posix.c | 139 ++++++++++++++++++++++---------------------
 1 file changed, 72 insertions(+), 67 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 6169bbf7a0..e7b82aaf37 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -2114,20 +2114,78 @@ int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
 #endif /* __linux__ */
 
 #if defined(__linux__) || defined(__FreeBSD__)
-void qmp_guest_set_user_password(const char *username,
-                                 const char *password,
-                                 bool crypted,
-                                 Error **errp)
+
+static void run_command(const char *argv[], const char *in_str, Error **errp)
 {
     Error *local_err = NULL;
-    char *passwd_path = NULL;
     pid_t pid;
-    int status;
+    int in_len, status;
     int datafd[2] = { -1, -1 };
+
+    if (!g_unix_open_pipe(datafd, FD_CLOEXEC, NULL)) {
+        error_setg(errp, "cannot create pipe FDs");
+        goto out;
+    }
+
+    pid = fork();
+    if (pid == 0) {
+        close(datafd[1]);
+        setsid();
+        dup2(datafd[0], 0);
+        reopen_fd_to_null(1);
+        reopen_fd_to_null(2);
+
+        execve(argv[0], (char *const *)argv, environ);
+        _exit(EXIT_FAILURE);
+    } else if (pid < 0) {
+        error_setg_errno(errp, errno, "failed to create child process");
+        goto out;
+    }
+    close(datafd[0]);
+    datafd[0] = -1;
+
+    in_len = strlen(in_str);
+
+    if (qemu_write_full(datafd[1], in_str, in_len) != in_len) {
+        error_setg_errno(errp, errno, "cannot write new account password");
+        goto out;
+    }
+    close(datafd[1]);
+    datafd[1] = -1;
+
+    ga_wait_child(pid, &status, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        goto out;
+    }
+
+    if (!WIFEXITED(status)) {
+        error_setg(errp, "child process has terminated abnormally");
+        goto out;
+    }
+
+    if (WEXITSTATUS(status)) {
+        error_setg(errp, "child process has failed: %s", argv[0]);
+    }
+
+out:
+    if (datafd[0] != -1) {
+        close(datafd[0]);
+    }
+    if (datafd[1] != -1) {
+        close(datafd[1]);
+    }
+}
+
+void qmp_guest_set_user_password(const char *username,
+                                 const char *password,
+                                 bool crypted,
+                                 Error **errp)
+{
+    char *passwd_path = NULL;
     char *rawpasswddata = NULL;
-    size_t rawpasswdlen;
     char *chpasswddata = NULL;
-    size_t chpasswdlen;
+    size_t rawpasswdlen;
 
     rawpasswddata = (char *)qbase64_decode(password, -1, &rawpasswdlen, errp);
     if (!rawpasswddata) {
@@ -2155,79 +2213,26 @@ void qmp_guest_set_user_password(const char *username,
     passwd_path = g_find_program_in_path("chpasswd");
 #endif
 
-    chpasswdlen = strlen(chpasswddata);
-
     if (!passwd_path) {
         error_setg(errp, "cannot find 'passwd' program in PATH");
         goto out;
     }
 
-    if (!g_unix_open_pipe(datafd, FD_CLOEXEC, NULL)) {
-        error_setg(errp, "cannot create pipe FDs");
-        goto out;
-    }
-
-    pid = fork();
-    if (pid == 0) {
-        close(datafd[1]);
-        /* child */
-        setsid();
-        dup2(datafd[0], 0);
-        reopen_fd_to_null(1);
-        reopen_fd_to_null(2);
-
+    const char *argv[] = {
 #ifdef __FreeBSD__
-        const char *h_arg;
-        h_arg = (crypted) ? "-H" : "-h";
-        execl(passwd_path, "pw", "usermod", "-n", username, h_arg, "0", NULL);
+        passwd_path, "pw", "usermod", "-n", username,
+        (crypted) ? "-H" : "-h", "0", NULL};
 #else
-        if (crypted) {
-            execl(passwd_path, "chpasswd", "-e", NULL);
-        } else {
-            execl(passwd_path, "chpasswd", NULL);
-        }
+        passwd_path, "chpasswd", (crypted) ? "-e" : NULL, NULL
 #endif
-        _exit(EXIT_FAILURE);
-    } else if (pid < 0) {
-        error_setg_errno(errp, errno, "failed to create child process");
-        goto out;
-    }
-    close(datafd[0]);
-    datafd[0] = -1;
+    };
 
-    if (qemu_write_full(datafd[1], chpasswddata, chpasswdlen) != chpasswdlen) {
-        error_setg_errno(errp, errno, "cannot write new account password");
-        goto out;
-    }
-    close(datafd[1]);
-    datafd[1] = -1;
-
-    ga_wait_child(pid, &status, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        goto out;
-    }
-
-    if (!WIFEXITED(status)) {
-        error_setg(errp, "child process has terminated abnormally");
-        goto out;
-    }
-
-    if (WEXITSTATUS(status)) {
-        error_setg(errp, "child process has failed to set user password");
-        goto out;
-    }
+    run_command(argv, chpasswddata, errp);
 
 out:
     g_free(chpasswddata);
     g_free(rawpasswddata);
     g_free(passwd_path);
-    if (datafd[0] != -1) {
-        close(datafd[0]);
-    }
-    if (datafd[1] != -1) {
-        close(datafd[1]);
-    }
 }
 #else /* __linux__ || __FreeBSD__ */
 void qmp_guest_set_user_password(const char *username,
-- 
2.34.1