#include <unistd.h>
#include "libbb.h"
-extern FILE *gz_open(FILE *compressed_file, int *pid)
+static int gz_use_vfork;
+
+FILE *gz_open(FILE * compressed_file, int *pid)
{
int unzip_pipe[2];
+ off_t floc;
+ int cfile = -1;
+
+ gz_use_vfork = (getenv("OPKG_USE_VFORK") != NULL);
+
+ if (gz_use_vfork) {
+ /* Create a new file descriptor for the input stream
+ * (it *must* be associated with a file), and lseek()
+ * to the same position in that fd as the stream.
+ */
+ cfile = dup(fileno(compressed_file));
+ floc = ftello(compressed_file);
+ lseek(cfile, floc, SEEK_SET);
+ setenv("GZIP", "--quiet", 0);
+ }
+
+ if (pipe(unzip_pipe) != 0) {
+ perror_msg("pipe");
+ return (NULL);
+ }
+
+ /* If we don't flush, we end up with two copies of anything pending,
+ one from the parent, one from the child */
+ fflush(stdout);
+ fflush(stderr);
- if (pipe(unzip_pipe)!=0) {
- error_msg("pipe error");
- return(NULL);
+ if (gz_use_vfork) {
+ *pid = vfork();
+ } else {
+ *pid = fork();
}
- if ((*pid = fork()) == -1) {
- error_msg("fork failed");
- return(NULL);
+
+ if (*pid < 0) {
+ perror_msg("fork");
+ return (NULL);
}
- if (*pid==0) {
+
+ if (*pid == 0) {
/* child process */
close(unzip_pipe[0]);
- unzip(compressed_file, fdopen(unzip_pipe[1], "w"));
- fflush(NULL);
- fclose(compressed_file);
- close(unzip_pipe[1]);
- exit(EXIT_SUCCESS);
+ if (gz_use_vfork) {
+ dup2(unzip_pipe[1], 1);
+ dup2(cfile, 0);
+ execlp("gunzip", "gunzip", NULL);
+ /* If we get here, we had a failure */
+ _exit(EXIT_FAILURE);
+ } else {
+ unzip(compressed_file, fdopen(unzip_pipe[1], "w"));
+ fflush(NULL);
+ fclose(compressed_file);
+ close(unzip_pipe[1]);
+ _exit(EXIT_SUCCESS);
+ }
}
- close(unzip_pipe[1]);
- if (unzip_pipe[0] == -1) {
- error_msg("gzip stream init failed");
+ /* Parent process is executing here */
+ if (gz_use_vfork) {
+ close(cfile);
}
- return(fdopen(unzip_pipe[0], "r"));
+ close(unzip_pipe[1]);
+ return (fdopen(unzip_pipe[0], "r"));
}
-/* gz_open implementation using gunzip and a vfork/exec -- dodges OOM killer */
-extern FILE *gzvopen(FILE *compressed_file, int *pid)
+int gz_close(int gunzip_pid)
{
- int unzip_pipe[2];
- off_t floc;
- int cfile;
-
- /* create a new file descriptor for the input stream
- * (it *must* be associated with a file)
- * and seek to the same position in that fd as the stream.
- */
- cfile = dup(fileno(compressed_file));
- floc = ftello(compressed_file);
- lseek(cfile, floc, SEEK_SET);
-
- /* create the pipe */
- if (pipe(unzip_pipe)!=0) {
- error_msg("gzvopen(): pipe error");
- return(NULL);
+ int status;
+ int ret;
+
+ if (gz_use_vfork) {
+ /* The gunzip process remains running in the background if we
+ * used the vfork()/exec() technique - so we have to kill it
+ * forcibly. There might be a better way to do this, but that
+ * affect a lot of other parts of opkg, and this works fine.
+ */
+ if (kill(gunzip_pid, SIGTERM) == -1) {
+ perror_msg("gz_close(): unable to kill gunzip pid.");
+ return -1;
+ }
}
- *pid = vfork();
-
- if (*pid < 0) {
- error_msg("gzvopen(): fork failed");
- return(NULL);
+ if (waitpid(gunzip_pid, &status, 0) == -1) {
+ perror_msg("waitpid");
+ return -1;
}
- if (*pid==0) {
- /* child process - reads STDIN, writes to pipe */
-
- /* close unused read end of pipe */
- close(unzip_pipe[0]);
-
- /* connect child's stdout to the pipe write end */
- dup2(unzip_pipe[1], 1);
-
- /* connect child's stdin to the fd passed in to us */
- dup2(cfile, 0);
-
- /* execute the gunzip utility */
- execlp("gunzip","gunzip",NULL);
-
- /* if we get here, we had a failure - since we are
- * using vfork(), we cannot call exit(), must call _exit().
- */
- _exit(-1);
+ if (gz_use_vfork) {
+ /* Bail out here if we used the vfork()/exec() technique. */
+ return 0;
}
- /* Parent process is executing here */
-
- /* we have no more need of the duplicate fd */
- close(cfile);
+ if (WIFSIGNALED(status)) {
+ error_msg("Unzip process killed by signal %d.\n",
+ WTERMSIG(status));
+ return -1;
+ }
- /* close the write end of the pipe */
- close(unzip_pipe[1]);
+ if (!WIFEXITED(status)) {
+ /* shouldn't happen */
+ error_msg
+ ("Your system is broken: got status %d from waitpid.\n",
+ status);
+ return -1;
+ }
- /* return the read end of the pipe as a FILE */
- return(fdopen(unzip_pipe[0], "r"));
-}
+ if ((ret = WEXITSTATUS(status))) {
+ error_msg("Unzip process failed with return code %d.\n", ret);
+ return -1;
+ }
-extern void gzvclose(int gunzip_pid)
-{
- if (kill(gunzip_pid, SIGTERM) == -1) {
- perror("gzvclose()");
- fprintf(stderr,"%s: unable to kill gunzip pid.\n",
- __FUNCTION__);
- }
-
- if (waitpid(gunzip_pid, NULL, 0) == -1) {
- fprintf(stderr,"%s: unable to wait on gunzip pid.\n",
- __FUNCTION__);
- }
+ return 0;
}