upload android base code part3

android/bootable/recovery/applypatch/imgpatch.cpp

@@ -0,0 +1,291 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// See imgdiff.cpp in this directory for a description of the patch file
+// format.
+
+#include <applypatch/imgpatch.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/cdefs.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/memory.h>
+#include <applypatch/applypatch.h>
+#include <applypatch/imgdiff.h>
+#include <openssl/sha.h>
+#include <zlib.h>
+
+static inline int64_t Read8(const void *address) {
+  return android::base::get_unaligned<int64_t>(address);
+}
+
+static inline int32_t Read4(const void *address) {
+  return android::base::get_unaligned<int32_t>(address);
+}
+
+// This function is a wrapper of ApplyBSDiffPatch(). It has a custom sink function to deflate the
+// patched data and stream the deflated data to output.
+static bool ApplyBSDiffPatchAndStreamOutput(const uint8_t* src_data, size_t src_len,
+                                            const Value* patch, size_t patch_offset,
+                                            const char* deflate_header, SinkFn sink, SHA_CTX* ctx) {
+  size_t expected_target_length = static_cast<size_t>(Read8(deflate_header + 32));
+  int level = Read4(deflate_header + 40);
+  int method = Read4(deflate_header + 44);
+  int window_bits = Read4(deflate_header + 48);
+  int mem_level = Read4(deflate_header + 52);
+  int strategy = Read4(deflate_header + 56);
+
+  std::unique_ptr<z_stream, decltype(&deflateEnd)> strm(new z_stream(), deflateEnd);
+  strm->zalloc = Z_NULL;
+  strm->zfree = Z_NULL;
+  strm->opaque = Z_NULL;
+  strm->avail_in = 0;
+  strm->next_in = nullptr;
+  int ret = deflateInit2(strm.get(), level, method, window_bits, mem_level, strategy);
+  if (ret != Z_OK) {
+    LOG(ERROR) << "Failed to init uncompressed data deflation: " << ret;
+    return false;
+  }
+
+  // Define a custom sink wrapper that feeds to bspatch. It deflates the available patch data on
+  // the fly and outputs the compressed data to the given sink.
+  size_t actual_target_length = 0;
+  size_t total_written = 0;
+  static constexpr size_t buffer_size = 32768;
+  auto compression_sink = [&](const uint8_t* data, size_t len) -> size_t {
+    // The input patch length for an update never exceeds INT_MAX.
+    strm->avail_in = len;
+    strm->next_in = data;
+    do {
+      std::vector<uint8_t> buffer(buffer_size);
+      strm->avail_out = buffer_size;
+      strm->next_out = buffer.data();
+      if (actual_target_length + len < expected_target_length) {
+        ret = deflate(strm.get(), Z_NO_FLUSH);
+      } else {
+        ret = deflate(strm.get(), Z_FINISH);
+      }
+      if (ret != Z_OK && ret != Z_STREAM_END) {
+        LOG(ERROR) << "Failed to deflate stream: " << ret;
+        // zero length indicates an error in the sink function of bspatch().
+        return 0;
+      }
+
+      size_t have = buffer_size - strm->avail_out;
+      total_written += have;
+      if (sink(buffer.data(), have) != have) {
+        LOG(ERROR) << "Failed to write " << have << " compressed bytes to output.";
+        return 0;
+      }
+      if (ctx) SHA1_Update(ctx, buffer.data(), have);
+    } while ((strm->avail_in != 0 || strm->avail_out == 0) && ret != Z_STREAM_END);
+
+    actual_target_length += len;
+    return len;
+  };
+
+  if (ApplyBSDiffPatch(src_data, src_len, patch, patch_offset, compression_sink, nullptr) != 0) {
+    return false;
+  }
+
+  if (ret != Z_STREAM_END) {
+    LOG(ERROR) << "ret is expected to be Z_STREAM_END, but it's " << ret;
+    return false;
+  }
+
+  if (expected_target_length != actual_target_length) {
+    LOG(ERROR) << "target length is expected to be " << expected_target_length << ", but it's "
+               << actual_target_length;
+    return false;
+  }
+  LOG(DEBUG) << "bspatch writes " << total_written << " bytes in total to streaming output.";
+
+  return true;
+}
+
+int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const unsigned char* patch_data,
+                    size_t patch_size, SinkFn sink) {
+  Value patch(VAL_BLOB, std::string(reinterpret_cast<const char*>(patch_data), patch_size));
+
+  return ApplyImagePatch(old_data, old_size, &patch, sink, nullptr, nullptr);
+}
+
+/*
+ * Apply the patch given in 'patch_filename' to the source data given
+ * by (old_data, old_size).  Write the patched output to the 'output'
+ * file, and update the SHA context with the output data as well.
+ * Return 0 on success.
+ */
+int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value* patch, SinkFn sink,
+                    SHA_CTX* ctx, const Value* bonus_data) {
+  if (patch->data.size() < 12) {
+    printf("patch too short to contain header\n");
+    return -1;
+  }
+
+  // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
+  // (IMGDIFF1, which is no longer supported, used CHUNK_NORMAL and
+  // CHUNK_GZIP.)
+  size_t pos = 12;
+  const char* header = &patch->data[0];
+  if (memcmp(header, "IMGDIFF2", 8) != 0) {
+    printf("corrupt patch file header (magic number)\n");
+    return -1;
+  }
+
+  int num_chunks = Read4(header + 8);
+
+  for (int i = 0; i < num_chunks; ++i) {
+    // each chunk's header record starts with 4 bytes.
+    if (pos + 4 > patch->data.size()) {
+      printf("failed to read chunk %d record\n", i);
+      return -1;
+    }
+    int type = Read4(&patch->data[pos]);
+    pos += 4;
+
+    if (type == CHUNK_NORMAL) {
+      const char* normal_header = &patch->data[pos];
+      pos += 24;
+      if (pos > patch->data.size()) {
+        printf("failed to read chunk %d normal header data\n", i);
+        return -1;
+      }
+
+      size_t src_start = static_cast<size_t>(Read8(normal_header));
+      size_t src_len = static_cast<size_t>(Read8(normal_header + 8));
+      size_t patch_offset = static_cast<size_t>(Read8(normal_header + 16));
+
+      if (src_start + src_len > old_size) {
+        printf("source data too short\n");
+        return -1;
+      }
+      if (ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink, ctx) != 0) {
+        printf("Failed to apply bsdiff patch.\n");
+        return -1;
+      }
+    } else if (type == CHUNK_RAW) {
+      const char* raw_header = &patch->data[pos];
+      pos += 4;
+      if (pos > patch->data.size()) {
+        printf("failed to read chunk %d raw header data\n", i);
+        return -1;
+      }
+
+      size_t data_len = static_cast<size_t>(Read4(raw_header));
+
+      if (pos + data_len > patch->data.size()) {
+        printf("failed to read chunk %d raw data\n", i);
+        return -1;
+      }
+      if (ctx) SHA1_Update(ctx, &patch->data[pos], data_len);
+      if (sink(reinterpret_cast<const unsigned char*>(&patch->data[pos]), data_len) != data_len) {
+        printf("failed to write chunk %d raw data\n", i);
+        return -1;
+      }
+      pos += data_len;
+    } else if (type == CHUNK_DEFLATE) {
+      // deflate chunks have an additional 60 bytes in their chunk header.
+      const char* deflate_header = &patch->data[pos];
+      pos += 60;
+      if (pos > patch->data.size()) {
+        printf("failed to read chunk %d deflate header data\n", i);
+        return -1;
+      }
+
+      size_t src_start = static_cast<size_t>(Read8(deflate_header));
+      size_t src_len = static_cast<size_t>(Read8(deflate_header + 8));
+      size_t patch_offset = static_cast<size_t>(Read8(deflate_header + 16));
+      size_t expanded_len = static_cast<size_t>(Read8(deflate_header + 24));
+
+      if (src_start + src_len > old_size) {
+        printf("source data too short\n");
+        return -1;
+      }
+
+      // Decompress the source data; the chunk header tells us exactly
+      // how big we expect it to be when decompressed.
+
+      // Note: expanded_len will include the bonus data size if
+      // the patch was constructed with bonus data.  The
+      // deflation will come up 'bonus_size' bytes short; these
+      // must be appended from the bonus_data value.
+      size_t bonus_size = (i == 1 && bonus_data != NULL) ? bonus_data->data.size() : 0;
+
+      std::vector<unsigned char> expanded_source(expanded_len);
+
+      // inflate() doesn't like strm.next_out being a nullptr even with
+      // avail_out being zero (Z_STREAM_ERROR).
+      if (expanded_len != 0) {
+        z_stream strm;
+        strm.zalloc = Z_NULL;
+        strm.zfree = Z_NULL;
+        strm.opaque = Z_NULL;
+        strm.avail_in = src_len;
+        strm.next_in = old_data + src_start;
+        strm.avail_out = expanded_len;
+        strm.next_out = expanded_source.data();
+
+        int ret = inflateInit2(&strm, -15);
+        if (ret != Z_OK) {
+          printf("failed to init source inflation: %d\n", ret);
+          return -1;
+        }
+
+        // Because we've provided enough room to accommodate the output
+        // data, we expect one call to inflate() to suffice.
+        ret = inflate(&strm, Z_SYNC_FLUSH);
+        if (ret != Z_STREAM_END) {
+          printf("source inflation returned %d\n", ret);
+          return -1;
+        }
+        // We should have filled the output buffer exactly, except
+        // for the bonus_size.
+        if (strm.avail_out != bonus_size) {
+          printf("source inflation short by %zu bytes\n", strm.avail_out - bonus_size);
+          return -1;
+        }
+        inflateEnd(&strm);
+
+        if (bonus_size) {
+          memcpy(expanded_source.data() + (expanded_len - bonus_size), &bonus_data->data[0],
+                 bonus_size);
+        }
+      }
+
+      if (!ApplyBSDiffPatchAndStreamOutput(expanded_source.data(), expanded_len, patch,
+                                           patch_offset, deflate_header, sink, ctx)) {
+        LOG(ERROR) << "Fail to apply streaming bspatch.";
+        return -1;
+      }
+
+    } else {
+      printf("patch chunk %d is unknown type %d\n", i, type);
+      return -1;
+    }
+  }
+
+  return 0;
+}