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Commit 8fce75a0 authored by Tao Bao's avatar Tao Bao
Browse files

applypatch: Clean up LoadPartitionContents(). 

We don't need three vectors to sort the (size, SHA-1) pairs.

Test: recovery_component_test passes.
Test: Apply a package that calls apply_patch_check() to patch EMMC
      partitions.
Change-Id: I4a6620630a6711f490822cf30f1e7fe5cea6ce49
parent c470dc86

applypatch/applypatch.cpp

+257 −283
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
 * limitations under the License.

 */



#include "applypatch/applypatch.h"



#include <errno.h>

#include <fcntl.h>

#include <libgen.h>
@@ -27,16 +29,18 @@ 


#include <memory>

#include <string>

#include <utility>

#include <vector>



#include <android-base/parseint.h>

#include <android-base/strings.h>

#include <openssl/sha.h>



#include "openssl/sha.h"

#include "applypatch/applypatch.h"

#include "edify/expr.h"

#include "ota_io.h"

#include "print_sha1.h"



static int LoadPartitionContents(const char* filename, FileContents* file);

static int LoadPartitionContents(const std::string& filename, FileContents* file);

static ssize_t FileSink(const unsigned char* data, ssize_t len, void* token);

static int GenerateTarget(FileContents* source_file,

                          const Value* source_patch_value,
@@ -48,36 +52,31 @@ static int GenerateTarget(FileContents* source_file, 
                          size_t target_size,

                          const Value* bonus_data);



// Read a file into memory; store the file contents and associated

// metadata in *file.

//

// Read a file into memory; store the file contents and associated metadata in *file.

// Return 0 on success.

int LoadFileContents(const char* filename, FileContents* file) {

    // A special 'filename' beginning with "EMMC:" means to

    // load the contents of a partition.

  // A special 'filename' beginning with "EMMC:" means to load the contents of a partition.

  if (strncmp(filename, "EMMC:", 5) == 0) {

    return LoadPartitionContents(filename, file);

  }



    if (stat(filename, &file->st) != 0) {

  if (stat(filename, &file->st) == -1) {

    printf("failed to stat \"%s\": %s\n", filename, strerror(errno));

    return -1;

  }



  std::vector<unsigned char> data(file->st.st_size);

    FILE* f = ota_fopen(filename, "rb");

    if (f == NULL) {

  std::unique_ptr<FILE, decltype(&ota_fclose)> f(ota_fopen(filename, "rb"), ota_fclose);

  if (!f) {

    printf("failed to open \"%s\": %s\n", filename, strerror(errno));

    return -1;

  }



    size_t bytes_read = ota_fread(data.data(), 1, data.size(), f);

  size_t bytes_read = ota_fread(data.data(), 1, data.size(), f.get());

  if (bytes_read != data.size()) {

    printf("short read of \"%s\" (%zu bytes of %zu)\n", filename, bytes_read, data.size());

        ota_fclose(f);

    return -1;

  }

    ota_fclose(f);

  file->data = std::move(data);

  SHA1(file->data.data(), file->data.size(), file->sha1);

  return 0;
@@ -97,72 +96,59 @@ int LoadFileContents(const char* filename, FileContents* file) { 
// "end-of-file" marker), so the caller must specify the possible

// lengths and the hash of the data, and we'll do the load expecting

// to find one of those hashes.

static int LoadPartitionContents(const char* filename, FileContents* file) {

    std::string copy(filename);

    std::vector<std::string> pieces = android::base::Split(copy, ":");

    if (pieces.size() < 4 || pieces.size() % 2 != 0) {

        printf("LoadPartitionContents called with bad filename (%s)\n", filename);

static int LoadPartitionContents(const std::string& filename, FileContents* file) {

  std::vector<std::string> pieces = android::base::Split(filename, ":");

  if (pieces.size() < 4 || pieces.size() % 2 != 0 || pieces[0] != "EMMC") {

    printf("LoadPartitionContents called with bad filename \"%s\"\n", filename.c_str());

    return -1;

  }



    if (pieces[0] != "EMMC") {

        printf("LoadPartitionContents called with bad filename (%s)\n", filename);

        return -1;

    }

    const char* partition = pieces[1].c_str();



    size_t pairs = (pieces.size() - 2) / 2;    // # of (size, sha1) pairs in filename

    std::vector<size_t> index(pairs);

    std::vector<size_t> size(pairs);

    std::vector<std::string> sha1sum(pairs);



    for (size_t i = 0; i < pairs; ++i) {

        size[i] = strtol(pieces[i*2+2].c_str(), NULL, 10);

        if (size[i] == 0) {

            printf("LoadPartitionContents called with bad size (%s)\n", filename);

  size_t pair_count = (pieces.size() - 2) / 2;  // # of (size, sha1) pairs in filename

  std::vector<std::pair<size_t, std::string>> pairs;

  for (size_t i = 0; i < pair_count; ++i) {

    size_t size;

    if (!android::base::ParseUint(pieces[i * 2 + 2], &size) || size == 0) {

      printf("LoadPartitionContents called with bad size \"%s\"\n", pieces[i * 2 + 2].c_str());

      return -1;

    }

        sha1sum[i] = pieces[i*2+3].c_str();

        index[i] = i;

    pairs.push_back({ size, pieces[i * 2 + 3] });

  }



    // Sort the index[] array so it indexes the pairs in order of increasing size.

    sort(index.begin(), index.end(),

        [&](const size_t& i, const size_t& j) {

            return (size[i] < size[j]);

        }

    );

  // Sort the pairs array so that they are in order of increasing size.

  std::sort(pairs.begin(), pairs.end());



    FILE* dev = ota_fopen(partition, "rb");

    if (dev == NULL) {

  const char* partition = pieces[1].c_str();

  std::unique_ptr<FILE, decltype(&ota_fclose)> dev(ota_fopen(partition, "rb"), ota_fclose);

  if (!dev) {

    printf("failed to open emmc partition \"%s\": %s\n", partition, strerror(errno));

    return -1;

  }



  SHA_CTX sha_ctx;

  SHA1_Init(&sha_ctx);

    uint8_t parsed_sha[SHA_DIGEST_LENGTH];



  // Allocate enough memory to hold the largest size.

    std::vector<unsigned char> data(size[index[pairs-1]]);

    char* p = reinterpret_cast<char*>(data.data());

    size_t data_size = 0;                // # bytes read so far

  std::vector<unsigned char> buffer(pairs[pair_count - 1].first);

  unsigned char* buffer_ptr = buffer.data();

  size_t buffer_size = 0;  // # bytes read so far

  bool found = false;



    for (size_t i = 0; i < pairs; ++i) {

  for (const auto& pair : pairs) {

    size_t current_size = pair.first;

    const std::string& current_sha1 = pair.second;



    // Read enough additional bytes to get us up to the next size. (Again,

    // we're trying the possibilities in order of increasing size).

        size_t next = size[index[i]] - data_size;

    size_t next = current_size - buffer_size;

    if (next > 0) {

            size_t read = ota_fread(p, 1, next, dev);

      size_t read = ota_fread(buffer_ptr, 1, next, dev.get());

      if (next != read) {

                printf("short read (%zu bytes of %zu) for partition \"%s\"\n",

                       read, next, partition);

        printf("short read (%zu bytes of %zu) for partition \"%s\"\n", read, next, partition);

        return -1;

      }

            SHA1_Update(&sha_ctx, p, read);

            data_size += read;

            p += read;

      SHA1_Update(&sha_ctx, buffer_ptr, read);

      buffer_size += read;

      buffer_ptr += read;

    }



    // Duplicate the SHA context and finalize the duplicate so we can
@@ -172,33 +158,30 @@ static int LoadPartitionContents(const char* filename, FileContents* file) { 
    uint8_t sha_so_far[SHA_DIGEST_LENGTH];

    SHA1_Final(sha_so_far, &temp_ctx);



        if (ParseSha1(sha1sum[index[i]].c_str(), parsed_sha) != 0) {

            printf("failed to parse sha1 %s in %s\n", sha1sum[index[i]].c_str(), filename);

    uint8_t parsed_sha[SHA_DIGEST_LENGTH];

    if (ParseSha1(current_sha1.c_str(), parsed_sha) != 0) {

      printf("failed to parse SHA-1 %s in %s\n", current_sha1.c_str(), filename.c_str());

      return -1;

    }



    if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_LENGTH) == 0) {

            // we have a match.  stop reading the partition; we'll return

            // the data we've read so far.

            printf("partition read matched size %zu sha %s\n",

                   size[index[i]], sha1sum[index[i]].c_str());

      // We have a match. Stop reading the partition; we'll return the data we've read so far.

      printf("partition read matched size %zu SHA-1 %s\n", current_size, current_sha1.c_str());

      found = true;

      break;

    }

  }



    ota_fclose(dev);



  if (!found) {

    // Ran off the end of the list of (size, sha1) pairs without finding a match.

        printf("contents of partition \"%s\" didn't match %s\n", partition, filename);

    printf("contents of partition \"%s\" didn't match %s\n", partition, filename.c_str());

    return -1;

  }



  SHA1_Final(file->sha1, &sha_ctx);



    data.resize(data_size);

    file->data = std::move(data);

  buffer.resize(buffer_size);

  file->data = std::move(buffer);

  // Fake some stat() info.

  file->st.st_mode = 0644;

  file->st.st_uid = 0;
@@ -250,18 +233,13 @@ int SaveFileContents(const char* filename, const FileContents* file) { 
// might contain multiple colons, but WriteToPartition() only uses the first

// two and ignores the rest. Return 0 on success.

int WriteToPartition(const unsigned char* data, size_t len, const char* target) {

    std::string copy(target);

    std::vector<std::string> pieces = android::base::Split(copy, ":");

  std::vector<std::string> pieces = android::base::Split(std::string(target), ":");



    if (pieces.size() < 2) {

  if (pieces.size() < 2 || pieces[0] != "EMMC") {

    printf("WriteToPartition called with bad target (%s)\n", target);

    return -1;

  }



    if (pieces[0] != "EMMC") {

        printf("WriteToPartition called with bad target (%s)\n", target);

        return -1;

    }

  const char* partition = pieces[1].c_str();



  size_t start = 0;
@@ -288,6 +266,7 @@ int WriteToPartition(const unsigned char* data, size_t len, const char* target) 
      }

      start += written;

    }



    if (ota_fsync(fd) != 0) {

      printf("failed to sync to %s (%s)\n", partition, strerror(errno));

      return -1;
@@ -296,14 +275,14 @@ int WriteToPartition(const unsigned char* data, size_t len, const char* target) 
      printf("failed to close %s (%s)\n", partition, strerror(errno));

      return -1;

    }



    fd = ota_open(partition, O_RDONLY);

    if (fd < 0) {

      printf("failed to reopen %s for verify (%s)\n", partition, strerror(errno));

      return -1;

    }



        // Drop caches so our subsequent verification read

        // won't just be reading the cache.

    // Drop caches so our subsequent verification read won't just be reading the cache.

    sync();

    int dc = ota_open("/proc/sys/vm/drop_caches", O_WRONLY);

    if (TEMP_FAILURE_RETRY(ota_write(dc, "3\n", 2)) == -1) {
@@ -316,10 +295,10 @@ int WriteToPartition(const unsigned char* data, size_t len, const char* target) 


    // verify

    if (TEMP_FAILURE_RETRY(lseek(fd, 0, SEEK_SET)) == -1) {

            printf("failed to seek back to beginning of %s: %s\n",

                   partition, strerror(errno));

      printf("failed to seek back to beginning of %s: %s\n", partition, strerror(errno));

      return -1;

    }



    unsigned char buffer[4096];

    start = len;

    for (size_t p = 0; p < len; p += sizeof(buffer)) {
@@ -330,19 +309,17 @@ int WriteToPartition(const unsigned char* data, size_t len, const char* target) 


      size_t so_far = 0;

      while (so_far < to_read) {

                ssize_t read_count =

                    TEMP_FAILURE_RETRY(ota_read(fd, buffer+so_far, to_read-so_far));

        ssize_t read_count = TEMP_FAILURE_RETRY(ota_read(fd, buffer + so_far, to_read - so_far));

        if (read_count == -1) {

                    printf("verify read error %s at %zu: %s\n",

                           partition, p, strerror(errno));

          printf("verify read error %s at %zu: %s\n", partition, p, strerror(errno));

          return -1;

        } else if (read_count == 0) {

          printf("verify read reached unexpected EOF, %s at %zu\n", partition, p);

          return -1;

        }

        if (static_cast<size_t>(read_count) < to_read) {

                    printf("short verify read %s at %zu: %zd %zu %s\n",

                           partition, p, read_count, to_read, strerror(errno));

          printf("short verify read %s at %zu: %zd %zu %s\n", partition, p, read_count, to_read,

                 strerror(errno));

        }

        so_far += read_count;

      }
@@ -375,7 +352,6 @@ int WriteToPartition(const unsigned char* data, size_t len, const char* target) 
  return 0;

}





// Take a string 'str' of 40 hex digits and parse it into the 20

// byte array 'digest'.  'str' may contain only the digest or be of

// the form "<digest>:<anything>".  Return 0 on success, -1 on any
@@ -430,16 +406,14 @@ int applypatch_check(const char* filename, const std::vector<std::string>& patch 
  // partitions, where the filename encodes the sha1s; no need to

  // check them twice.)

  if (LoadFileContents(filename, &file) != 0 ||

        (patch_sha1_str.size() > 0 && FindMatchingPatch(file.sha1, patch_sha1_str) < 0)) {

        printf("file \"%s\" doesn't have any of expected "

               "sha1 sums; checking cache\n", filename);

      (!patch_sha1_str.empty() && FindMatchingPatch(file.sha1, patch_sha1_str) < 0)) {

    printf("file \"%s\" doesn't have any of expected sha1 sums; checking cache\n", filename);



    // If the source file is missing or corrupted, it might be because

    // we were killed in the middle of patching it.  A copy of it

    // should have been made in CACHE_TEMP_SOURCE.  If that file

    // exists and matches the sha1 we're looking for, the check still

    // passes.



    if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) {

      printf("failed to load cache file\n");

      return 1;
@@ -544,10 +518,8 @@ int applypatch(const char* source_filename, 
        return 1;

    }



    FileContents copy_file;

    FileContents source_file;

    const Value* source_patch_value = nullptr;

    const Value* copy_patch_value = nullptr;



    // We try to load the target file into the source_file object.

    if (LoadFileContents(target_filename, &source_file) == 0) {
@@ -575,6 +547,8 @@ int applypatch(const char* source_filename, 
        }

    }



    FileContents copy_file;

    const Value* copy_patch_value = nullptr;

    if (source_patch_value == nullptr) {

        source_file.data.clear();

        printf("source file is bad; trying copy\n");
@@ -620,7 +594,6 @@ int applypatch_flash(const char* source_filename, const char* target_filename, 
        return 1;

    }



    FileContents source_file;

    std::string target_str(target_filename);



    std::vector<std::string> pieces = android::base::Split(target_str, ":");
@@ -633,7 +606,8 @@ int applypatch_flash(const char* source_filename, const char* target_filename, 
    pieces.push_back(std::to_string(target_size));

    pieces.push_back(target_sha1_str);

    std::string fullname = android::base::Join(pieces, ':');

    if (LoadPartitionContents(fullname.c_str(), &source_file) == 0 &&

    FileContents source_file;

    if (LoadPartitionContents(fullname, &source_file) == 0 &&

        memcmp(source_file.sha1, target_sha1, SHA_DIGEST_LENGTH) == 0) {

      // The early-exit case: the image was already applied, this partition

      // has the desired hash, nothing for us to do.