+/*
+ * Copyright (C) 2016 Jo-Philipp Wich <jo@mein.io>
+ * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
+ *
+ * Zlib decrompression utility routines.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <poll.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include "gzip.h"
+
+static void
+to_devnull(int fd)
+{
+ int devnull = open("/dev/null", fd ? O_WRONLY : O_RDONLY);
+
+ if (devnull >= 0)
+ dup2(devnull, fd);
+
+ if (devnull > STDERR_FILENO)
+ close(devnull);
+}
+
+void *
+gzip_thread(void *ptr)
+{
+ struct gzip_handle *zh = ptr;
+ char buf[4096];
+ int len, ret;
+
+ while (1) {
+ if (zh->file)
+ len = fread(buf, 1, sizeof(buf), zh->file);
+ else if (zh->gzip)
+ len = gzip_read(zh->gzip, buf, sizeof(buf));
+
+ if (len <= 0)
+ break;
+
+ do {
+ ret = write(zh->wfd, buf, len);
+ } while (ret == -1 && errno == EINTR);
+ }
+
+ close(zh->wfd);
+ zh->wfd = -1;
+}
+
+int
+gzip_exec(struct gzip_handle *zh, const char *filename)
+{
+ int rpipe[2] = { -1, -1 }, wpipe[2] = { -1, -1 };
+ struct sigaction pipe_sa = { .sa_handler = SIG_IGN };
+
+ zh->rfd = -1;
+ zh->wfd = -1;
+
+ if (sigaction(SIGPIPE, &pipe_sa, &zh->pipe_sa) < 0)
+ return -1;
+
+ if (pipe(rpipe) < 0)
+ return -1;
+
+ if (!filename && pipe(wpipe) < 0) {
+ close(rpipe[0]);
+ close(rpipe[1]);
+ return -1;
+ }
+
+ zh->pid = vfork();
+
+ switch (zh->pid) {
+ case -1:
+ return -1;
+
+ case 0:
+ to_devnull(STDERR_FILENO);
+
+ if (filename) {
+ to_devnull(STDIN_FILENO);
+ }
+ else {
+ dup2(wpipe[0], STDIN_FILENO);
+ close(wpipe[0]);
+ close(wpipe[1]);
+ }
+
+ dup2(rpipe[1], STDOUT_FILENO);
+ close(rpipe[0]);
+ close(rpipe[1]);
+
+ execlp("gzip", "gzip", "-d", "-c", filename, NULL);
+ exit(-1);
+
+ default:
+ zh->rfd = rpipe[0];
+ zh->wfd = wpipe[1];
+
+ fcntl(zh->rfd, F_SETFD, fcntl(zh->rfd, F_GETFD) | FD_CLOEXEC);
+ close(rpipe[1]);
+
+ if (zh->wfd >= 0) {
+ fcntl(zh->wfd, F_SETFD, fcntl(zh->wfd, F_GETFD) | FD_CLOEXEC);
+ close(wpipe[0]);
+ pthread_create(&zh->thread, NULL, gzip_thread, zh);
+ }
+ }
+
+ return 0;
+}
+
+ssize_t
+gzip_read(struct gzip_handle *zh, char *buf, ssize_t len)
+{
+ ssize_t ret;
+
+ do {
+ ret = read(zh->rfd, buf, len);
+ } while (ret == -1 && errno != EINTR);
+
+ return ret;
+}
+
+ssize_t
+gzip_copy(struct gzip_handle *zh, FILE *out, ssize_t len)
+{
+ char buf[4096];
+ ssize_t rlen, total = 0;
+
+ while (len > 0) {
+ rlen = gzip_read(zh, buf,
+ (len > sizeof(buf)) ? sizeof(buf) : len);
+
+ if (rlen <= 0)
+ break;
+
+ if (out != NULL) {
+ if (fwrite(buf, 1, rlen, out) != rlen)
+ break;
+ }
+
+ len -= rlen;
+ total += rlen;
+ }
+
+ return total;
+}
+
+FILE *
+gzip_fdopen(struct gzip_handle *zh, const char *filename)
+{
+ memset(zh, 0, sizeof(*zh));
+
+ if (!filename || gzip_exec(zh, filename) < 0)
+ return NULL;
+
+ fcntl(zh->rfd, F_SETFL, fcntl(zh->rfd, F_GETFL) & ~O_NONBLOCK);
+
+ return fdopen(zh->rfd, "r");
+}
+
+int
+gzip_close(struct gzip_handle *zh)
+{
+ int code = -1;
+
+ if (zh->rfd >= 0)
+ close(zh->rfd);
+
+ if (zh->wfd >= 0)
+ close(zh->wfd);
+
+ if (zh->pid > 0) {
+ kill(zh->pid, SIGKILL);
+ waitpid(zh->pid, &code, 0);
+ }
+
+ if (zh->file)
+ fclose(zh->file);
+
+ if (zh->thread)
+ pthread_join(zh->thread, NULL);
+
+ sigaction(SIGPIPE, &zh->pipe_sa, NULL);
+
+ return WIFEXITED(code) ? WEXITSTATUS(code) : -1;
+}
projects / project / opkg-lede.git / commitdiff