tar + gzip/bzip2/etc: support NOMMU machines (by Alex Landau <landau_alex@yahoo.com>)

9 files changed, 92 insertions, 42 deletions

diff --git a/archival/bbunzip.c b/archival/bbunzip.c
index 56c742a49..a4e525f2e 100644
--- a/archival/bbunzip.c
+++ b/archival/bbunzip.c
@@ -298,7 +298,7 @@ USE_DESKTOP(long long) int unpack_unlzma(void)
 int unlzma_main(int argc, char **argv);
 int unlzma_main(int argc, char **argv)
 {
-        getopt32(argv, "c");
+        getopt32(argv, "cf");
         argv += optind;
         /* lzmacat? */
         if (applet_name[4] == 'c')
diff --git a/archival/libunarchive/Kbuild b/archival/libunarchive/Kbuild
index 3c29d541a..d104524e4 100644
--- a/archival/libunarchive/Kbuild
+++ b/archival/libunarchive/Kbuild
@@ -35,36 +35,34 @@ DPKG_FILES:= \
         get_header_tar.o \
         filter_accept_list_reassign.o
 
-# open_transformer uses fork(). Compile it only if absolutely necessary
 lib-$(CONFIG_RPM)                       += open_transformer.o
-lib-$(CONFIG_FEATURE_TAR_BZIP2)         += open_transformer.o
-lib-$(CONFIG_FEATURE_TAR_LZMA)          += open_transformer.o
-lib-$(CONFIG_FEATURE_TAR_GZIP)          += open_transformer.o
-lib-$(CONFIG_FEATURE_TAR_COMPRESS)      += open_transformer.o
-lib-$(CONFIG_FEATURE_DEB_TAR_GZ)        += open_transformer.o
-lib-$(CONFIG_FEATURE_DEB_TAR_BZ2)       += open_transformer.o
-lib-$(CONFIG_FEATURE_DEB_TAR_LZMA)      += open_transformer.o
-
-lib-$(CONFIG_AR)                        += get_header_ar.o unpack_ar_archive.o
-lib-$(CONFIG_BUNZIP2)                   += decompress_bunzip2.o
-lib-$(CONFIG_UNLZMA)                    += decompress_unlzma.o
-lib-$(CONFIG_CPIO)                      += get_header_cpio.o
-lib-$(CONFIG_DPKG)                      += $(DPKG_FILES)
-lib-$(CONFIG_DPKG_DEB)                  += $(DPKG_FILES)
-lib-$(CONFIG_FEATURE_DEB_TAR_GZ)        += $(GUNZIP_FILES) get_header_tar_gz.o
-lib-$(CONFIG_FEATURE_DEB_TAR_BZ2)       += decompress_bunzip2.o get_header_tar_bz2.o
-lib-$(CONFIG_FEATURE_DEB_TAR_LZMA)      += decompress_unlzma.o get_header_tar_lzma.o
-lib-$(CONFIG_GUNZIP)                    += $(GUNZIP_FILES)
-lib-$(CONFIG_FEATURE_GUNZIP_UNCOMPRESS) += decompress_uncompress.o
-lib-$(CONFIG_RPM2CPIO)                  += $(GUNZIP_FILES) get_header_cpio.o
-lib-$(CONFIG_RPM)                       += $(GUNZIP_FILES) get_header_cpio.o
-lib-$(CONFIG_FEATURE_RPM_BZ2)           += decompress_bunzip2.o
-lib-$(CONFIG_TAR)                       += get_header_tar.o
-lib-$(CONFIG_FEATURE_TAR_BZIP2)         += decompress_bunzip2.o get_header_tar_bz2.o
-lib-$(CONFIG_FEATURE_TAR_LZMA)          += decompress_unlzma.o get_header_tar_lzma.o
-lib-$(CONFIG_FEATURE_TAR_GZIP)          += $(GUNZIP_FILES) get_header_tar_gz.o
-lib-$(CONFIG_FEATURE_TAR_COMPRESS)      += decompress_uncompress.o
-lib-$(CONFIG_UNCOMPRESS)                += decompress_uncompress.o
-lib-$(CONFIG_UNZIP)                     += $(GUNZIP_FILES)
-lib-$(CONFIG_FEATURE_COMPRESS_USAGE)    += decompress_bunzip2.o
+lib-$(CONFIG_FEATURE_TAR_BZIP2)         += open_transformer.o
+lib-$(CONFIG_FEATURE_TAR_LZMA)          += open_transformer.o
+lib-$(CONFIG_FEATURE_TAR_GZIP)          += open_transformer.o
+lib-$(CONFIG_FEATURE_TAR_COMPRESS)      += open_transformer.o
+lib-$(CONFIG_FEATURE_DEB_TAR_GZ)        += open_transformer.o
+lib-$(CONFIG_FEATURE_DEB_TAR_BZ2)       += open_transformer.o
+lib-$(CONFIG_FEATURE_DEB_TAR_LZMA)      += open_transformer.o
 
+lib-$(CONFIG_AR)                        += get_header_ar.o unpack_ar_archive.o
+lib-$(CONFIG_BUNZIP2)                   += decompress_bunzip2.o
+lib-$(CONFIG_UNLZMA)                    += decompress_unlzma.o
+lib-$(CONFIG_CPIO)                      += get_header_cpio.o
+lib-$(CONFIG_DPKG)                      += $(DPKG_FILES)
+lib-$(CONFIG_DPKG_DEB)                  += $(DPKG_FILES)
+lib-$(CONFIG_FEATURE_DEB_TAR_GZ)        += $(GUNZIP_FILES) get_header_tar_gz.o
+lib-$(CONFIG_FEATURE_DEB_TAR_BZ2)       += decompress_bunzip2.o get_header_tar_bz2.o
+lib-$(CONFIG_FEATURE_DEB_TAR_LZMA)      += decompress_unlzma.o get_header_tar_lzma.o
+lib-$(CONFIG_GUNZIP)                    += $(GUNZIP_FILES)
+lib-$(CONFIG_FEATURE_GUNZIP_UNCOMPRESS) += decompress_uncompress.o
+lib-$(CONFIG_RPM2CPIO)                  += $(GUNZIP_FILES) get_header_cpio.o
+lib-$(CONFIG_RPM)                       += $(GUNZIP_FILES) get_header_cpio.o
+lib-$(CONFIG_FEATURE_RPM_BZ2)           += decompress_bunzip2.o
+lib-$(CONFIG_TAR)                       += get_header_tar.o
+lib-$(CONFIG_FEATURE_TAR_BZIP2)         += decompress_bunzip2.o get_header_tar_bz2.o
+lib-$(CONFIG_FEATURE_TAR_LZMA)          += decompress_unlzma.o get_header_tar_lzma.o
+lib-$(CONFIG_FEATURE_TAR_GZIP)          += $(GUNZIP_FILES) get_header_tar_gz.o
+lib-$(CONFIG_FEATURE_TAR_COMPRESS)      += decompress_uncompress.o
+lib-$(CONFIG_UNCOMPRESS)                += decompress_uncompress.o
+lib-$(CONFIG_UNZIP)                     += $(GUNZIP_FILES)
+lib-$(CONFIG_FEATURE_COMPRESS_USAGE)    += decompress_bunzip2.o
diff --git a/archival/libunarchive/get_header_tar_bz2.c b/archival/libunarchive/get_header_tar_bz2.c
index e11f44cad..8f7f83fc2 100644
--- a/archival/libunarchive/get_header_tar_bz2.c
+++ b/archival/libunarchive/get_header_tar_bz2.c
@@ -11,7 +11,7 @@ char get_header_tar_bz2(archive_handle_t *archive_handle)
         /* Can't lseek over pipes */
         archive_handle->seek = seek_by_read;
 
-        archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_bz2_stream);
+        archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_bz2_stream, "bunzip2", "bunzip2", "-cf", "-", NULL);
         archive_handle->offset = 0;
         while (get_header_tar(archive_handle) == EXIT_SUCCESS) /**/;
 
diff --git a/archival/libunarchive/get_header_tar_gz.c b/archival/libunarchive/get_header_tar_gz.c
index 85070d978..a99061411 100644
--- a/archival/libunarchive/get_header_tar_gz.c
+++ b/archival/libunarchive/get_header_tar_gz.c
@@ -8,19 +8,26 @@
 
 char get_header_tar_gz(archive_handle_t *archive_handle)
 {
+#if BB_MMU
         unsigned char magic[2];
+#endif
 
         /* Can't lseek over pipes */
         archive_handle->seek = seek_by_read;
 
+        /* Check gzip magic only if open_transformer will invoke unpack_gz_stream (MMU case).
+         * Otherwise, it will invoke an external helper "gunzip -cf" (NOMMU case) which will
+         * need the header. */
+#if BB_MMU
         xread(archive_handle->src_fd, &magic, 2);
         if ((magic[0] != 0x1f) || (magic[1] != 0x8b)) {
                 bb_error_msg_and_die("invalid gzip magic");
         }
 
         check_header_gzip_or_die(archive_handle->src_fd);
+#endif
 
-        archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_gz_stream);
+        archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_gz_stream, "gunzip", "gunzip", "-cf", "-", NULL);
         archive_handle->offset = 0;
         while (get_header_tar(archive_handle) == EXIT_SUCCESS) /**/;
 
diff --git a/archival/libunarchive/get_header_tar_lzma.c b/archival/libunarchive/get_header_tar_lzma.c
index 771f664f2..f0e45f2c5 100644
--- a/archival/libunarchive/get_header_tar_lzma.c
+++ b/archival/libunarchive/get_header_tar_lzma.c
@@ -14,7 +14,7 @@ char get_header_tar_lzma(archive_handle_t * archive_handle)
         /* Can't lseek over pipes */
         archive_handle->seek = seek_by_read;
 
-        archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_lzma_stream);
+        archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_lzma_stream, "unlzma", "unlzma", "-cf", "-", NULL);
         archive_handle->offset = 0;
         while (get_header_tar(archive_handle) == EXIT_SUCCESS) /**/;
 
diff --git a/archival/libunarchive/open_transformer.c b/archival/libunarchive/open_transformer.c
index 93f01be6f..f8f587e8d 100644
--- a/archival/libunarchive/open_transformer.c
+++ b/archival/libunarchive/open_transformer.c
@@ -7,29 +7,48 @@
 #include "unarchive.h"
 
 /* transformer(), more than meets the eye */
+/*
+ * On MMU machine, the transform_prog and ... are stripped
+ * by a macro in include/unarchive.h. On NOMMU, transformer is stripped.
+ */
 int open_transformer(int src_fd,
-        USE_DESKTOP(long long) int (*transformer)(int src_fd, int dst_fd))
+        USE_DESKTOP(long long) int (*transformer)(int src_fd, int dst_fd),
+        const char *transform_prog, ...)
 {
         int fd_pipe[2];
         int pid;
 
         xpipe(fd_pipe);
 
+#if BB_MMU
         pid = fork();
-        if (pid == -1) {
+#else
+        pid = vfork();
+#endif
+        if (pid == -1)
                 bb_perror_msg_and_die("fork failed");
-        }
 
         if (pid == 0) {
+#if !BB_MMU
+                va_list ap;
+#endif
                 /* child process */
                 close(fd_pipe[0]); /* We don't wan't to read from the parent */
                 // FIXME: error check?
+#if BB_MMU
                 transformer(src_fd, fd_pipe[1]);
                 if (ENABLE_FEATURE_CLEAN_UP) {
                         close(fd_pipe[1]); /* Send EOF */
                         close(src_fd);
                 }
                 exit(0);
+#else
+                xmove_fd(src_fd, 0);
+                xmove_fd(fd_pipe[1], 1);
+                va_start(ap, transform_prog);
+                BB_EXECVP(transform_prog, ap);
+                bb_perror_and_die("exec failed");
+#endif
                 /* notreached */
         }
 
diff --git a/archival/rpm.c b/archival/rpm.c
index 674ee2640..4d723b73f 100644
--- a/archival/rpm.c
+++ b/archival/rpm.c
@@ -187,9 +187,15 @@ int rpm_main(int argc, char **argv)
 
 static void extract_cpio_gz(int fd)
 {
-        USE_DESKTOP(long long) int (*xformer)(int src_fd, int dst_fd);
         archive_handle_t *archive_handle;
         unsigned char magic[2];
+#if BB_MMU
+        USE_DESKTOP(long long) int (*xformer)(int src_fd, int dst_fd);
+        enum { xformer_prog = 0 };
+#else
+        enum { xformer = 0 };
+        const char *xformer_prog;
+#endif
 
         /* Initialize */
         archive_handle = init_handle();
@@ -202,11 +208,19 @@ static void extract_cpio_gz(int fd)
         archive_handle->offset = 0;
 
         xread(archive_handle->src_fd, &magic, 2);
+#if BB_MMU
         xformer = unpack_gz_stream;
+#else
+        xformer_prog = "gunzip";
+#endif
         if ((magic[0] != 0x1f) || (magic[1] != 0x8b)) {
                 if (ENABLE_FEATURE_RPM_BZ2
                  && (magic[0] == 0x42) && (magic[1] == 0x5a)) {
+#if BB_MMU
                         xformer = unpack_bz2_stream;
+#else
+                        xformer_prog = "bunzip2";
+#endif
         /* We can do better, need modifying unpack_bz2_stream to not require
          * first 2 bytes. Not very hard to do... I mean, TODO :) */
                         xlseek(archive_handle->src_fd, -2, SEEK_CUR);
@@ -214,11 +228,17 @@ static void extract_cpio_gz(int fd)
                         bb_error_msg_and_die("no gzip"
                                 USE_FEATURE_RPM_BZ2("/bzip")
                                 " magic");
-        } else
+        } else {
                 check_header_gzip_or_die(archive_handle->src_fd);
+#if !BB_MMU
+                /* NOMMU version of open_transformer execs an external unzipper that should
+                 * have the file position at the start of the file */
+                xlseek(archive_handle->src_fd, 0, SEEK_SET);
+#endif
+        }
 
         xchdir("/"); /* Install RPM's to root */
-        archive_handle->src_fd = open_transformer(archive_handle->src_fd, xformer);
+        archive_handle->src_fd = open_transformer(archive_handle->src_fd, xformer, xformer_prog, xformer_prog, "-cf", "-", NULL);
         archive_handle->offset = 0;
         while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
                 continue;
diff --git a/archival/tar.c b/archival/tar.c
index f0d397114..e0d4daff7 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -660,7 +660,7 @@ static char get_header_tar_Z(archive_handle_t *archive_handle)
                 bb_error_msg_and_die("invalid magic");
         }
 
-        archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress);
+        archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress, "uncompress", "uncompress", "-cf", "-", NULL);
         archive_handle->offset = 0;
         while (get_header_tar(archive_handle) == EXIT_SUCCESS)
                 /* nothing */;
diff --git a/include/unarchive.h b/include/unarchive.h
index bea055852..51ec89cc0 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -115,7 +115,13 @@ extern USE_DESKTOP(long long) int inflate_unzip(inflate_unzip_result *res, unsig
 extern USE_DESKTOP(long long) int unpack_gz_stream(int src_fd, int dst_fd);
 extern USE_DESKTOP(long long) int unpack_lzma_stream(int src_fd, int dst_fd);
 
+#if BB_MMU
 extern int open_transformer(int src_fd,
         USE_DESKTOP(long long) int (*transformer)(int src_fd, int dst_fd));
+#define open_transformer(src_fd, transformer, transform_prog, ...) open_transformer(src_fd, transformer)
+#else
+extern int open_transformer(int src_fd, const char *transform_prog, ...);
+#define open_transformer(src_fd, transformer, transform_prog, ...) open_transformer(src_fd, transform_prog, __VA_ARGS__)
+#endif
 
 #endif