applypatch changes for patching recovery image
Make some changes needed to applypatch in order to store the recovery
image in the system partition as a binary patch relative to the boot
image:
- make applypatch use shared libraries, so it's smaller. It will
need to be on the main system so it can install the recovery
image. Make an applypatch_static binary for use in recovery
packages (still needed for updating cupcake devices to donut).
- output the results of patching to an in-memory buffer and write
that to the partition; there's no convenient /tmp for us to us.
(This should be basically a no-op in recovery, since /tmp is a
ramdisk anyway.)
diff --git a/tools/applypatch/applypatch.c b/tools/applypatch/applypatch.c
index 06089ea..394c584 100644
--- a/tools/applypatch/applypatch.c
+++ b/tools/applypatch/applypatch.c
@@ -282,9 +282,10 @@
return 0;
}
-// Copy the contents of source_file to target_mtd partition, a string
-// of the form "MTD:<partition>[:...]". Return 0 on success.
-int CopyToMTDPartition(const char* source_file, const char* target_mtd) {
+// Write a memory buffer to target_mtd partition, a string of the form
+// "MTD:<partition>[:...]". Return 0 on success.
+int WriteToMTDPartition(unsigned char* data, size_t len,
+ const char* target_mtd) {
char* partition = strchr(target_mtd, ':');
if (partition == NULL) {
fprintf(stderr, "bad MTD target name \"%s\"\n", target_mtd);
@@ -298,13 +299,6 @@
if (end != NULL)
*end = '\0';
- FILE* f = fopen(source_file, "rb");
- if (f == NULL) {
- fprintf(stderr, "failed to open %s for reading: %s\n",
- source_file, strerror(errno));
- return -1;
- }
-
if (!mtd_partitions_scanned) {
mtd_scan_partitions();
mtd_partitions_scanned = 1;
@@ -323,20 +317,14 @@
return -1;
}
- const int buffer_size = 4096;
- char buffer[buffer_size];
- size_t read;
- while ((read = fread(buffer, 1, buffer_size, f)) > 0) {
- size_t written = mtd_write_data(ctx, buffer, read);
- if (written != read) {
- fprintf(stderr, "only wrote %d of %d bytes to MTD %s\n",
- written, read, partition);
- mtd_write_close(ctx);
- return -1;
- }
+ size_t written = mtd_write_data(ctx, (char*)data, len);
+ if (written != len) {
+ fprintf(stderr, "only wrote %d of %d bytes to MTD %s\n",
+ written, len, partition);
+ mtd_write_close(ctx);
+ return -1;
}
- fclose(f);
if (mtd_erase_blocks(ctx, -1) < 0) {
fprintf(stderr, "error finishing mtd write of %s\n", partition);
mtd_write_close(ctx);
@@ -476,6 +464,26 @@
return 0;
}
+size_t FileSink(unsigned char* data, size_t len, void* token) {
+ return fwrite(data, 1, len, (FILE*)token);
+}
+
+typedef struct {
+ unsigned char* buffer;
+ size_t size;
+ size_t pos;
+} MemorySinkInfo;
+
+size_t MemorySink(unsigned char* data, size_t len, void* token) {
+ MemorySinkInfo* msi = (MemorySinkInfo*)token;
+ if (msi->size - msi->pos < len) {
+ return -1;
+ }
+ memcpy(msi->buffer + msi->pos, data, len);
+ msi->pos += len;
+ return len;
+}
+
// Return the amount of free space (in bytes) on the filesystem
// containing filename. filename must exist. Return -1 on error.
size_t FreeSpaceForFile(const char* filename) {
@@ -720,19 +728,36 @@
}
char* outname = NULL;
+ FILE* output = NULL;
+ MemorySinkInfo msi;
+ SinkFn sink = NULL;
+ void* token = NULL;
if (strncmp(target_filename, "MTD:", 4) == 0) {
- outname = MTD_TARGET_TEMP_FILE;
+ // We store the decoded output in memory.
+ msi.buffer = malloc(target_size);
+ if (msi.buffer == NULL) {
+ fprintf(stderr, "failed to alloc %ld bytes for output\n",
+ (long)target_size);
+ return 1;
+ }
+ msi.pos = 0;
+ msi.size = target_size;
+ sink = MemorySink;
+ token = &msi;
} else {
// We write the decoded output to "<tgt-file>.patch".
outname = (char*)malloc(strlen(target_filename) + 10);
strcpy(outname, target_filename);
strcat(outname, ".patch");
- }
- FILE* output = fopen(outname, "wb");
- if (output == NULL) {
- fprintf(stderr, "failed to open output file %s: %s\n",
- outname, strerror(errno));
- return 1;
+
+ output = fopen(outname, "wb");
+ if (output == NULL) {
+ fprintf(stderr, "failed to open output file %s: %s\n",
+ outname, strerror(errno));
+ return 1;
+ }
+ sink = FileSink;
+ token = output;
}
#define MAX_HEADER_LENGTH 8
@@ -759,7 +784,7 @@
} else if (header_bytes_read >= 8 &&
memcmp(header, "BSDIFF40", 8) == 0) {
int result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size,
- patch_filename, 0, output, &ctx);
+ patch_filename, 0, sink, token, &ctx);
if (result != 0) {
fprintf(stderr, "ApplyBSDiffPatch failed\n");
return result;
@@ -768,7 +793,7 @@
memcmp(header, "IMGDIFF", 7) == 0 &&
(header[7] == '1' || header[7] == '2')) {
int result = ApplyImagePatch(source_to_use->data, source_to_use->size,
- patch_filename, output, &ctx);
+ patch_filename, sink, token, &ctx);
if (result != 0) {
fprintf(stderr, "ApplyImagePatch failed\n");
return result;
@@ -778,9 +803,11 @@
return 1;
}
- fflush(output);
- fsync(fileno(output));
- fclose(output);
+ if (output != NULL) {
+ fflush(output);
+ fsync(fileno(output));
+ fclose(output);
+ }
const uint8_t* current_target_sha1 = SHA_final(&ctx);
if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) {
@@ -788,13 +815,13 @@
return 1;
}
- if (strcmp(outname, MTD_TARGET_TEMP_FILE) == 0) {
+ if (output == NULL) {
// Copy the temp file to the MTD partition.
- if (CopyToMTDPartition(outname, target_filename) != 0) {
- fprintf(stderr, "copy of %s to %s failed\n", outname, target_filename);
+ if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) {
+ fprintf(stderr, "write of patched data to %s failed\n", target_filename);
return 1;
}
- unlink(outname);
+ free(msi.buffer);
} else {
// Give the .patch file the same owner, group, and mode of the
// original source file.