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-rw-r--r--minzip/SysUtil.cpp212
1 files changed, 212 insertions, 0 deletions
diff --git a/minzip/SysUtil.cpp b/minzip/SysUtil.cpp
new file mode 100644
index 000000000..4cdd60d9f
--- /dev/null
+++ b/minzip/SysUtil.cpp
@@ -0,0 +1,212 @@
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * System utilities.
+ */
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <android-base/logging.h>
+
+#include "SysUtil.h"
+
+static bool sysMapFD(int fd, MemMapping* pMap) {
+ assert(pMap != NULL);
+
+ struct stat sb;
+ if (fstat(fd, &sb) == -1) {
+ PLOG(ERROR) << "fstat(" << fd << ") failed";
+ return false;
+ }
+
+ void* memPtr = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (memPtr == MAP_FAILED) {
+ PLOG(ERROR) << "mmap(" << sb.st_size << ", R, PRIVATE, " << fd << ", 0) failed";
+ return false;
+ }
+
+ pMap->addr = reinterpret_cast<unsigned char*>(memPtr);
+ pMap->length = sb.st_size;
+ pMap->range_count = 1;
+ pMap->ranges = reinterpret_cast<MappedRange*>(malloc(sizeof(MappedRange)));
+ if (pMap->ranges == NULL) {
+ PLOG(ERROR) << "malloc failed";
+ munmap(memPtr, sb.st_size);
+ return false;
+ }
+ pMap->ranges[0].addr = memPtr;
+ pMap->ranges[0].length = sb.st_size;
+
+ return true;
+}
+
+static int sysMapBlockFile(FILE* mapf, MemMapping* pMap)
+{
+ char block_dev[PATH_MAX+1];
+ size_t size;
+ unsigned int blksize;
+ size_t blocks;
+ unsigned int range_count;
+ unsigned int i;
+
+ if (fgets(block_dev, sizeof(block_dev), mapf) == NULL) {
+ PLOG(ERROR) << "failed to read block device from header";
+ return -1;
+ }
+ for (i = 0; i < sizeof(block_dev); ++i) {
+ if (block_dev[i] == '\n') {
+ block_dev[i] = 0;
+ break;
+ }
+ }
+
+ if (fscanf(mapf, "%zu %u\n%u\n", &size, &blksize, &range_count) != 3) {
+ LOG(ERROR) << "failed to parse block map header";
+ return -1;
+ }
+ if (blksize != 0) {
+ blocks = ((size-1) / blksize) + 1;
+ }
+ if (size == 0 || blksize == 0 || blocks > SIZE_MAX / blksize || range_count == 0) {
+ LOG(ERROR) << "invalid data in block map file: size " << size << ", blksize " << blksize
+ << ", range_count " << range_count;
+ return -1;
+ }
+
+ pMap->range_count = range_count;
+ pMap->ranges = reinterpret_cast<MappedRange*>(calloc(range_count, sizeof(MappedRange)));
+ if (pMap->ranges == NULL) {
+ PLOG(ERROR) << "calloc(" << range_count << ", " << sizeof(MappedRange) << ") failed";
+ return -1;
+ }
+
+ // Reserve enough contiguous address space for the whole file.
+ unsigned char* reserve = reinterpret_cast<unsigned char*>(mmap64(NULL, blocks * blksize,
+ PROT_NONE, MAP_PRIVATE | MAP_ANON, -1, 0));
+ if (reserve == MAP_FAILED) {
+ PLOG(ERROR) << "failed to reserve address space";
+ free(pMap->ranges);
+ return -1;
+ }
+
+ int fd = open(block_dev, O_RDONLY);
+ if (fd < 0) {
+ PLOG(ERROR) << "failed to open block device " << block_dev;
+ munmap(reserve, blocks * blksize);
+ free(pMap->ranges);
+ return -1;
+ }
+
+ unsigned char* next = reserve;
+ size_t remaining_size = blocks * blksize;
+ bool success = true;
+ for (i = 0; i < range_count; ++i) {
+ size_t start, end;
+ if (fscanf(mapf, "%zu %zu\n", &start, &end) != 2) {
+ LOG(ERROR) << "failed to parse range " << i << " in block map";
+ success = false;
+ break;
+ }
+ size_t length = (end - start) * blksize;
+ if (end <= start || ((end - start) > SIZE_MAX / blksize) || length > remaining_size) {
+ LOG(ERROR) << "unexpected range in block map: " << start << " " << end;
+ success = false;
+ break;
+ }
+
+ void* addr = mmap64(next, length, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, ((off64_t)start)*blksize);
+ if (addr == MAP_FAILED) {
+ PLOG(ERROR) << "failed to map block " << i;
+ success = false;
+ break;
+ }
+ pMap->ranges[i].addr = addr;
+ pMap->ranges[i].length = length;
+
+ next += length;
+ remaining_size -= length;
+ }
+ if (success && remaining_size != 0) {
+ LOG(ERROR) << "ranges in block map are invalid: remaining_size = " << remaining_size;
+ success = false;
+ }
+ if (!success) {
+ close(fd);
+ munmap(reserve, blocks * blksize);
+ free(pMap->ranges);
+ return -1;
+ }
+
+ close(fd);
+ pMap->addr = reserve;
+ pMap->length = size;
+
+ LOG(INFO) << "mmapped " << range_count << " ranges";
+
+ return 0;
+}
+
+int sysMapFile(const char* fn, MemMapping* pMap)
+{
+ memset(pMap, 0, sizeof(*pMap));
+
+ if (fn && fn[0] == '@') {
+ // A map of blocks
+ FILE* mapf = fopen(fn+1, "r");
+ if (mapf == NULL) {
+ PLOG(ERROR) << "Unable to open '" << (fn+1) << "'";
+ return -1;
+ }
+
+ if (sysMapBlockFile(mapf, pMap) != 0) {
+ LOG(ERROR) << "Map of '" << fn << "' failed";
+ fclose(mapf);
+ return -1;
+ }
+
+ fclose(mapf);
+ } else {
+ // This is a regular file.
+ int fd = open(fn, O_RDONLY);
+ if (fd == -1) {
+ PLOG(ERROR) << "Unable to open '" << fn << "'";
+ return -1;
+ }
+
+ if (!sysMapFD(fd, pMap)) {
+ LOG(ERROR) << "Map of '" << fn << "' failed";
+ close(fd);
+ return -1;
+ }
+
+ close(fd);
+ }
+ return 0;
+}
+
+/*
+ * Release a memory mapping.
+ */
+void sysReleaseMap(MemMapping* pMap)
+{
+ int i;
+ for (i = 0; i < pMap->range_count; ++i) {
+ if (munmap(pMap->ranges[i].addr, pMap->ranges[i].length) < 0) {
+ PLOG(ERROR) << "munmap(" << pMap->ranges[i].addr << ", " << pMap->ranges[i].length
+ << ") failed";
+ }
+ }
+ free(pMap->ranges);
+ pMap->ranges = NULL;
+ pMap->range_count = 0;
+}