# This patchset implements the suggestion found in xsystem.c in the
# original opkg sources -- use vfork and exec instead of system().
#
# This, like the preceding patch in this patchset is vital to dodging
# the OOM killer on small-memory machines.
#
# Mike Westerhof, Dec 2008

--- orig/libopkg/opkg.c	2008-12-20 15:07:04.000000000 -0600
+++ opkg/libopkg/opkg.c	2008-12-21 21:41:07.000000000 -0600
@@ -31,6 +31,7 @@
 
 #include "sprintf_alloc.h"
 #include "file_util.h"
+#include "xsystem.h"
 
 #include <libbb/libbb.h>
 
--- orig/libopkg/xsystem.h	2008-03-01 12:55:29.000000000 -0600
+++ opkg/libopkg/xsystem.h	2008-12-21 21:41:07.000000000 -0600
@@ -29,6 +29,7 @@
    as defined in <sys/wait.h>.
 */
 int xsystem(const char *cmd);
+int xvsystem(const char *cmd, char *const argv[]);
 
 #endif
 	 
--- orig/libopkg/xsystem.c	2008-04-17 11:00:51.000000000 -0500
+++ opkg/libopkg/xsystem.c	2008-12-21 21:41:07.000000000 -0600
@@ -62,3 +62,58 @@
     return -1;
 }
 	 
+int xvsystem(const char *cmd, char *const argv[])
+{
+    int err;
+    pid_t pid;
+
+#ifdef DO_DEBUG
+    int i = 0;
+    char *p;
+    printf("DEBUG: xvsystem: execute ");
+    while (p = argv[i++]) {
+	    printf("\"%s\" ", p);
+    }
+    printf("\n");
+#endif
+
+    pid = vfork();
+
+    if (pid == 0) {		/* Child */
+	execvp(cmd, argv);
+	_exit(1);
+
+    } else if (pid == -1) {	/* Error on fork() */
+	perror("vfork()");
+	fprintf(stderr, "%s: ERROR: fork failed before execution: `%s'\n",
+		__FUNCTION__, cmd);
+	return -1;
+
+    } else {			/* Parent */
+	if (waitpid(pid, &err, 0) != pid) {	/* wait for child */
+	    perror("waitpid()");
+	    fprintf(stderr, "%s: ERROR: failed to execute: `%s'\n",
+		    __FUNCTION__, cmd);
+	    return -1;
+	}
+    }
+
+#ifdef DO_DEBUG
+    printf("DEBUG: xvsystem: child exit status %d\n", err);
+#endif
+
+    if (WIFSIGNALED(err)) {
+	fprintf(stderr, "%s: ERROR: Child process died due to signal %d: `%s'\n",
+		__FUNCTION__, WTERMSIG(err), cmd);
+	return -1;
+    }
+
+    if (WIFEXITED(err)) {
+	/* Normal child exit */
+	return WEXITSTATUS(err);
+    }
+
+    fprintf(stderr, "%s: ERROR: Received unintelligible return value from system: %d",
+	    __FUNCTION__, err);
+    return -1;
+}
--- orig/libopkg/opkg_conf.c	2008-12-20 15:06:50.000000000 -0600
+++ opkg/libopkg/opkg_conf.c	2008-12-21 21:41:07.000000000 -0600
@@ -316,10 +320,8 @@
      err = rmdir(conf->tmp_dir);
      if (err) {
 	  if (errno == ENOTEMPTY) {
-	       char *cmd;
-	       sprintf_alloc(&cmd, "rm -fr %s\n", conf->tmp_dir);
-	       err = xsystem(cmd);
-	       free(cmd);
+	       char *argv[] = {"rm", "-fr", conf->tmp_dir, NULL};
+	       err = xvsystem(argv[0], argv);
 	  }
 	  if (err)
 	       fprintf(stderr, "WARNING: Unable to remove temporary directory: %s: %s\n", conf->tmp_dir, strerror(errno));
--- orig/libopkg/opkg_install.c	2008-12-20 15:06:51.000000000 -0600
+++ opkg/libopkg/opkg_install.c	2008-12-21 21:41:07.000000000 -0600
@@ -1617,13 +1617,9 @@
 	  }
 
 	  if (strcmp(response, "d") == 0) {
-	       char *cmd;
-
+	       char *argv[] = {"diff", "-u", backup, file_name, NULL};
 	       free(response);
-	       /* XXX: BUG rewrite to use exec or busybox's internal diff */
-	       sprintf_alloc(&cmd, "diff -u %s %s", backup, file_name);
-	       xsystem(cmd);
-	       free(cmd);
+	       xvsystem(argv[0], argv);
 	       printf("    [Press ENTER to continue]\n");
 	       response = file_read_line_alloc(stdin);
 	       free(response);
--- orig/libopkg/pkg.c	2008-12-20 15:06:50.000000000 -0600
+++ opkg/libopkg/pkg.c	2008-12-21 23:31:39.000000000 -0600
@@ -1534,7 +1564,12 @@
      sprintf_alloc(&cmd, "%s %s", path, args);
      free(path);
 
-     err = xsystem(cmd);
+//     err = xsystem(cmd);
+     {
+	char *argv[] = {"sh", "-c", cmd, NULL};
+	err = xvsystem(argv[0], argv);
+     }
+
      free(cmd);
 
      if (err) {
--- orig/libopkg/opkg_cmd.c	2008-12-20 15:07:04.000000000 -0600
+++ opkg/libopkg/opkg_cmd.c	2008-12-21 21:41:07.000000000 -0600
@@ -33,6 +33,7 @@
 #include "libbb/libbb.h"
 #include "opkg_utils.h"
 #include "opkg_defines.h"
+#include "xsystem.h"
 
 #include <fnmatch.h>
 
@@ -371,7 +373,7 @@
 	    
 	    sprintf_alloc (&path, "%s/%s", ctx->statedir, de->d_name);
 	    if (access (path, X_OK) == 0) {
-		if (system (path)) {
+		if (system (path)) {   /* FIXME FIXME */
 		    err = errno;
 		    perror (de->d_name);
 		}
--- orig/libopkg/opkg_download.c	2008-12-20 15:07:04.000000000 -0600
+++ opkg/libopkg/opkg_download.c	2008-12-21 21:44:30.000000000 -0600
@@ -129,16 +129,21 @@
 #else
     {
       int res;
-      char *wgetcmd;
-      char *wgetopts;
-      wgetopts = getenv("OPKG_WGETOPTS");
-      sprintf_alloc(&wgetcmd, "wget -q %s%s -O \"%s\" \"%s\"",
-		    (conf->http_proxy || conf->ftp_proxy) ? "-Y on " : "",
-		    (wgetopts!=NULL) ? wgetopts : "",
-		    tmp_file_location, src);
-      opkg_message(conf, OPKG_INFO, "Executing: %s\n", wgetcmd);
-      res = xsystem(wgetcmd);
-      free(wgetcmd);
+      char *argv[16];
+      int i = 0;
+
+      argv[i++] = "wget";
+      argv[i++] = "-q";
+      if (conf->http_proxy || conf->ftp_proxy) {
+	 argv[i++] = "-Y";
+	 argv[i++] = "on";
+      }
+      argv[i++] = "-O";
+      argv[i++] = tmp_file_location;
+      argv[i++] = src;
+      argv[i++] = NULL;
+      res = xvsystem(argv[0], argv);
+
       if (res) {
 	opkg_message(conf, OPKG_ERROR, "Failed to download %s, error %d\n", src, res);
 	free(tmp_file_location);