use popen and redirect script output

Change the run_script function to use popen and to redirect
the output of the script to the log file.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 87d326522d950f9e63057b652d703c36ac1ad08c..a6550cfce81301523b9776b167219974b8543bfd 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -189,54 +189,57 @@ static struct caps_opt caps_opt[] = {
 static int run_script(const char *name, const char *section,
                      const char *script, ...)
 {
-       va_list argp;
-       int vargc = 4;
-       int status = 0;
-
-       /* count variable arguments and add 4 for script, container
-        * and section name  as well as the terminating NULL
-        */
-       va_start(argp, script);
-       while (va_arg(argp, char*)) vargc++;
-       va_end(argp);
+       int ret;
+       FILE *f;
+       char *buffer, *p, *output;
+       size_t size = 0;
+       va_list ap;
 
        INFO("Executing script '%s' for container '%s', config section '%s'",
             script, name, section);
 
-       int pid = fork();
-       if (pid < 0) {
-               ERROR("Error forking");
+
+       va_start(ap, script);
+       while ((p = va_arg(ap, char *)))
+               size += strlen(p);
+       va_end(ap);
+
+       size += strlen(script);
+       size += strlen(name);
+       size += strlen(section);
+
+       buffer = alloca(size + 1);
+       if (!buffer) {
+               ERROR("failed to allocate memory");
                return -1;
        }
 
-        if (pid == 0) {
+       ret = sprintf(buffer, "%s %s %s", script, name, section);
 
-               /* prepare command line arguments */
-               char *args[vargc];
-               int i;
-               args[0] = strdup(script);
-               args[1] = strdup(name);
-               args[2] = strdup(section);
+       va_start(ap, script);
+       while ((p = va_arg(ap, char *)))
+               ret += sprintf(buffer + ret, " %s", p);
+       va_end(ap);
 
-               va_start(argp, script);
-               for (i = 3; i < vargc; i++)
-                       args[i] = va_arg(argp, char*);
-               va_end(argp);
-
-               args[vargc-1] = (char*) NULL;
+       f = popen(buffer, "r");
+       if (!f) {
+               SYSERROR("popen failed");
+               return -1;
+       }
 
-               execv(script, args);
-               /* if we cannot exec, we exit this fork */
-               SYSERROR("Failed to execute script '%s' for container '%s': %s",
-                        script, name);
-               exit(1);
+       output = malloc(LXC_LOG_BUFFER_SIZE);
+       if (!output) {
+               ERROR("failed to allocate memory for script output");
+               return -1;
        }
 
-       waitpid(pid, &status, 0);
-       if (status != 0) {
-               /* something weird happened */
-               SYSERROR("Script '%s' terminated with non-zero exitcode %d",
-                        name, status);
+       while(fgets(output, LXC_LOG_BUFFER_SIZE, f))
+               DEBUG("script output: %s", output);
+
+       free(output);
+
+       if (pclose(f)) {
+               ERROR("Script exited on error");
                return -1;
        }