AOSP10 TWRP Merge: fix conflicts and update libraries needed

This allows flame to boot TWRP. Still will need to work on
super partition for vendor and system access.

The plan will be to cherry-pick any updates to android-9.0
through gerrit.twrp.me to this branch as a WIP.
diff --git a/fuse_sideload28/fuse_sideload.cpp b/fuse_sideload28/fuse_sideload.cpp
new file mode 100644
index 0000000..45c79f9
--- /dev/null
+++ b/fuse_sideload28/fuse_sideload.cpp
@@ -0,0 +1,525 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+// This module creates a special filesystem containing two files.
+//
+// "/sideload/package.zip" appears to be a normal file, but reading
+// from it causes data to be fetched from the adb host.  We can use
+// this to sideload packages over an adb connection without having to
+// store the entire package in RAM on the device.
+//
+// Because we may not trust the adb host, this filesystem maintains
+// the following invariant: each read of a given position returns the
+// same data as the first read at that position.  That is, once a
+// section of the file is read, future reads of that section return
+// the same data.  (Otherwise, a malicious adb host process could
+// return one set of bits when the package is read for signature
+// verification, and then different bits for when the package is
+// accessed by the installer.)  If the adb host returns something
+// different than it did on the first read, the reader of the file
+// will see their read fail with EINVAL.
+//
+// The other file, "/sideload/exit", is used to control the subprocess
+// that creates this filesystem.  Calling stat() on the exit file
+// causes the filesystem to be unmounted and the adb process on the
+// device shut down.
+//
+// Note that only the minimal set of file operations needed for these
+// two files is implemented.  In particular, you can't opendir() or
+// readdir() on the "/sideload" directory; ls on it won't work.
+
+#include "fuse_sideload.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include "fuse.h"
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/param.h>  // MIN
+#include <sys/stat.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#ifdef USE_MINCRYPT
+#include "mincrypt/sha256.h"
+#define  SHA256_DIGEST_LENGTH SHA256_DIGEST_SIZE
+#else
+#include <openssl/sha.h>
+#endif
+
+#include <array>
+#include <string>
+#include <vector>
+
+//#include <android-base/stringprintf.h>
+//#include <android-base/unique_fd.h>
+
+static constexpr uint64_t PACKAGE_FILE_ID = FUSE_ROOT_ID + 1;
+static constexpr uint64_t EXIT_FLAG_ID = FUSE_ROOT_ID + 2;
+
+static constexpr int NO_STATUS = 1;
+static constexpr int NO_STATUS_EXIT = 2;
+
+using SHA256Digest = std::array<uint8_t, SHA256_DIGEST_LENGTH>;
+
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+struct fuse_data {
+  int ffd;  // file descriptor for the fuse socket
+
+  provider_vtab vtab;
+
+  uint64_t file_size;  // bytes
+
+  uint32_t block_size;   // block size that the adb host is using to send the file to us
+  uint32_t file_blocks;  // file size in block_size blocks
+
+  uid_t uid;
+  gid_t gid;
+
+  uint32_t curr_block;  // cache the block most recently read from the host
+  uint8_t* block_data;
+
+  uint8_t* extra_block;  // another block of storage for reads that span two blocks
+
+  uint8_t* hashes;        // SHA-256 hash of each block (all zeros
+                          // if block hasn't been read yet)
+};
+
+static void fuse_reply(const fuse_data* fd, uint64_t unique, const void* data, size_t len) {
+  fuse_out_header hdr;
+  hdr.len = len + sizeof(hdr);
+  hdr.error = 0;
+  hdr.unique = unique;
+
+  struct iovec vec[2];
+  vec[0].iov_base = &hdr;
+  vec[0].iov_len = sizeof(hdr);
+  vec[1].iov_base = const_cast<void*>(data);
+  vec[1].iov_len = len;
+
+  int res = writev(fd->ffd, vec, 2);
+  if (res == -1) {
+    printf("*** REPLY FAILED *** %s\n", strerror(errno));
+  }
+}
+
+static int handle_init(void* data, fuse_data* fd, const fuse_in_header* hdr) {
+  const fuse_init_in* req = static_cast<const fuse_init_in*>(data);
+
+  // Kernel 2.6.16 is the first stable kernel with struct fuse_init_out defined (fuse version 7.6).
+  // The structure is the same from 7.6 through 7.22. Beginning with 7.23, the structure increased
+  // in size and added new parameters.
+  if (req->major != FUSE_KERNEL_VERSION || req->minor < 6) {
+    printf("Fuse kernel version mismatch: Kernel version %d.%d, Expected at least %d.6", req->major,
+           req->minor, FUSE_KERNEL_VERSION);
+    return -1;
+  }
+
+  fuse_init_out out;
+  out.minor = MIN(req->minor, FUSE_KERNEL_MINOR_VERSION);
+  size_t fuse_struct_size = sizeof(out);
+#if defined(FUSE_COMPAT_22_INIT_OUT_SIZE)
+  /* FUSE_KERNEL_VERSION >= 23. */
+
+  // If the kernel only works on minor revs older than or equal to 22, then use the older structure
+  // size since this code only uses the 7.22 version of the structure.
+  if (req->minor <= 22) {
+    fuse_struct_size = FUSE_COMPAT_22_INIT_OUT_SIZE;
+  }
+#endif
+
+  out.major = FUSE_KERNEL_VERSION;
+  out.max_readahead = req->max_readahead;
+  out.flags = 0;
+  out.max_background = 32;
+  out.congestion_threshold = 32;
+  out.max_write = 4096;
+  fuse_reply(fd, hdr->unique, &out, fuse_struct_size);
+
+  return NO_STATUS;
+}
+
+static void fill_attr(fuse_attr* attr, const fuse_data* fd, uint64_t nodeid, uint64_t size,
+                      uint32_t mode) {
+  memset(attr, 0, sizeof(*attr));
+  attr->nlink = 1;
+  attr->uid = fd->uid;
+  attr->gid = fd->gid;
+  attr->blksize = 4096;
+
+  attr->ino = nodeid;
+  attr->size = size;
+  attr->blocks = (size == 0) ? 0 : (((size - 1) / attr->blksize) + 1);
+  attr->mode = mode;
+}
+
+static int handle_getattr(void* /* data */, const fuse_data* fd, const fuse_in_header* hdr) {
+  struct fuse_attr_out out;
+  memset(&out, 0, sizeof(out));
+  out.attr_valid = 10;
+
+  if (hdr->nodeid == FUSE_ROOT_ID) {
+    fill_attr(&(out.attr), fd, hdr->nodeid, 4096, S_IFDIR | 0555);
+  } else if (hdr->nodeid == PACKAGE_FILE_ID) {
+    fill_attr(&(out.attr), fd, PACKAGE_FILE_ID, fd->file_size, S_IFREG | 0444);
+  } else if (hdr->nodeid == EXIT_FLAG_ID) {
+    fill_attr(&(out.attr), fd, EXIT_FLAG_ID, 0, S_IFREG | 0);
+  } else {
+    return -ENOENT;
+  }
+
+  fuse_reply(fd, hdr->unique, &out, sizeof(out));
+  return (hdr->nodeid == EXIT_FLAG_ID) ? NO_STATUS_EXIT : NO_STATUS;
+}
+
+static int handle_lookup(void* data, const fuse_data* fd, const fuse_in_header* hdr) {
+  if (data == nullptr) return -ENOENT;
+
+  struct fuse_entry_out out;
+  memset(&out, 0, sizeof(out));
+  out.entry_valid = 10;
+  out.attr_valid = 10;
+
+  std::string filename(static_cast<const char*>(data));
+  if (filename == FUSE_SIDELOAD_HOST_FILENAME) {
+    out.nodeid = PACKAGE_FILE_ID;
+    out.generation = PACKAGE_FILE_ID;
+    fill_attr(&(out.attr), fd, PACKAGE_FILE_ID, fd->file_size, S_IFREG | 0444);
+  } else if (filename == FUSE_SIDELOAD_HOST_EXIT_FLAG) {
+    out.nodeid = EXIT_FLAG_ID;
+    out.generation = EXIT_FLAG_ID;
+    fill_attr(&(out.attr), fd, EXIT_FLAG_ID, 0, S_IFREG | 0);
+  } else {
+    return -ENOENT;
+  }
+
+  fuse_reply(fd, hdr->unique, &out, sizeof(out));
+  return (out.nodeid == EXIT_FLAG_ID) ? NO_STATUS_EXIT : NO_STATUS;
+}
+
+static int handle_open(void* /* data */, const fuse_data* fd, const fuse_in_header* hdr) {
+  if (hdr->nodeid == EXIT_FLAG_ID) return -EPERM;
+  if (hdr->nodeid != PACKAGE_FILE_ID) return -ENOENT;
+
+  struct fuse_open_out out;
+  memset(&out, 0, sizeof(out));
+  out.fh = 10;  // an arbitrary number; we always use the same handle
+  fuse_reply(fd, hdr->unique, &out, sizeof(out));
+  return NO_STATUS;
+}
+
+static int handle_flush(void* /* data */, fuse_data* /* fd */, const fuse_in_header* /* hdr */) {
+  return 0;
+}
+
+static int handle_release(void* /* data */, fuse_data* /* fd */, const fuse_in_header* /* hdr */) {
+  return 0;
+}
+
+// Fetch a block from the host into fd->curr_block and fd->block_data.
+// Returns 0 on successful fetch, negative otherwise.
+static int fetch_block(fuse_data* fd, uint32_t block) {
+  if (block == fd->curr_block) {
+    return 0;
+  }
+
+  if (block >= fd->file_blocks) {
+    memset(fd->block_data, 0, fd->block_size);
+    fd->curr_block = block;
+    return 0;
+  }
+
+  size_t fetch_size = fd->block_size;
+  if (block * fd->block_size + fetch_size > fd->file_size) {
+    // If we're reading the last (partial) block of the file, expect a shorter response from the
+    // host, and pad the rest of the block with zeroes.
+    fetch_size = fd->file_size - (block * fd->block_size);
+    memset(fd->block_data + fetch_size, 0, fd->block_size - fetch_size);
+  }
+
+  int result = fd->vtab.read_block(block, fd->block_data, fetch_size);
+  if (result < 0) return result;
+
+  fd->curr_block = block;
+
+  // Verify the hash of the block we just got from the host.
+  //
+  // - If the hash of the just-received data matches the stored hash for the block, accept it.
+  // - If the stored hash is all zeroes, store the new hash and accept the block (this is the first
+  //   time we've read this block).
+  // - Otherwise, return -EINVAL for the read.
+
+  uint8_t hash[SHA256_DIGEST_LENGTH];
+#ifdef USE_MINCRYPT
+  SHA256_hash(fd->block_data, fd->block_size, hash);
+#else
+  SHA256(fd->block_data, fd->block_size, hash);
+#endif
+  uint8_t* blockhash = fd->hashes + block * SHA256_DIGEST_LENGTH;
+  if (memcmp(hash, blockhash, SHA256_DIGEST_LENGTH) == 0) {
+    return 0;
+  }
+
+  int i;
+  for (i = 0; i < SHA256_DIGEST_LENGTH; ++i) {
+    if (blockhash[i] != 0) {
+      fd->curr_block = -1;
+      return -EIO;
+    }
+  }
+
+  memcpy(blockhash, hash, SHA256_DIGEST_LENGTH);
+  return 0;
+}
+
+static int handle_read(void* data, fuse_data* fd, const fuse_in_header* hdr) {
+  if (hdr->nodeid != PACKAGE_FILE_ID) return -ENOENT;
+
+  const fuse_read_in* req = static_cast<const fuse_read_in*>(data);
+  uint64_t offset = req->offset;
+  uint32_t size = req->size;
+
+  // The docs on the fuse kernel interface are vague about what to do when a read request extends
+  // past the end of the file. We can return a short read -- the return structure does include a
+  // length field -- but in testing that caused the program using the file to segfault. (I
+  // speculate that this is due to the reading program accessing it via mmap; maybe mmap dislikes
+  // when you return something short of a whole page?) To fix this we zero-pad reads that extend
+  // past the end of the file so we're always returning exactly as many bytes as were requested.
+  // (Users of the mapped file have to know its real length anyway.)
+
+  fuse_out_header outhdr;
+  outhdr.len = sizeof(outhdr) + size;
+  outhdr.error = 0;
+  outhdr.unique = hdr->unique;
+
+  struct iovec vec[3];
+  vec[0].iov_base = &outhdr;
+  vec[0].iov_len = sizeof(outhdr);
+
+  uint32_t block = offset / fd->block_size;
+  int result = fetch_block(fd, block);
+  if (result != 0) return result;
+
+  // Two cases:
+  //
+  //   - the read request is entirely within this block. In this case we can reply immediately.
+  //
+  //   - the read request goes over into the next block. Note that since we mount the filesystem
+  //     with max_read=block_size, a read can never span more than two blocks. In this case we copy
+  //     the block to extra_block and issue a fetch for the following block.
+
+  uint32_t block_offset = offset - (block * fd->block_size);
+
+  int vec_used;
+  if (size + block_offset <= fd->block_size) {
+    // First case: the read fits entirely in the first block.
+
+    vec[1].iov_base = fd->block_data + block_offset;
+    vec[1].iov_len = size;
+    vec_used = 2;
+  } else {
+    // Second case: the read spills over into the next block.
+
+    memcpy(fd->extra_block, fd->block_data + block_offset, fd->block_size - block_offset);
+    vec[1].iov_base = fd->extra_block;
+    vec[1].iov_len = fd->block_size - block_offset;
+
+    result = fetch_block(fd, block + 1);
+    if (result != 0) return result;
+    vec[2].iov_base = fd->block_data;
+    vec[2].iov_len = size - vec[1].iov_len;
+    vec_used = 3;
+  }
+
+  if (writev(fd->ffd, vec, vec_used) == -1) {
+    printf("*** READ REPLY FAILED: %s ***\n", strerror(errno));
+  }
+  return NO_STATUS;
+}
+
+int run_fuse_sideload(const provider_vtab& vtab, uint64_t file_size, uint32_t block_size,
+                      const char* mount_point) {
+  // If something's already mounted on our mountpoint, try to remove it. (Mostly in case of a
+  // previous abnormal exit.)
+  umount2(mount_point, MNT_FORCE);
+
+  // fs/fuse/inode.c in kernel code uses the greater of 4096 and the passed-in max_read.
+  if (block_size < 4096) {
+    fprintf(stderr, "block size (%u) is too small\n", block_size);
+    return -1;
+  }
+  if (block_size > (1 << 22)) {  // 4 MiB
+    fprintf(stderr, "block size (%u) is too large\n", block_size);
+    return -1;
+  }
+
+  fuse_data fd;
+  memset(&fd, 0, sizeof(fd));
+  fd.vtab = vtab;
+  fd.file_size = file_size;
+  fd.block_size = block_size;
+  fd.file_blocks = (file_size == 0) ? 0 : (((file_size - 1) / block_size) + 1);
+
+  int result;
+  if (fd.file_blocks > (1 << 18)) {
+    fprintf(stderr, "file has too many blocks (%u)\n", fd.file_blocks);
+    result = -1;
+    goto done;
+  }
+
+  fd.hashes = (uint8_t*)calloc(fd.file_blocks, SHA256_DIGEST_LENGTH);
+  if (fd.hashes == NULL) {
+    fprintf(stderr, "failed to allocate %d bites for hashes\n",
+            fd.file_blocks * SHA256_DIGEST_LENGTH);
+    result = -1;
+    goto done;
+  }
+
+  fd.uid = getuid();
+  fd.gid = getgid();
+
+  fd.curr_block = -1;
+  fd.block_data = static_cast<uint8_t*>(malloc(block_size));
+  if (fd.block_data == nullptr) {
+    fprintf(stderr, "failed to allocate %d bites for block_data\n", block_size);
+    result = -1;
+    goto done;
+  }
+  fd.extra_block = static_cast<uint8_t*>(malloc(block_size));
+  if (fd.extra_block == nullptr) {
+    fprintf(stderr, "failed to allocate %d bites for extra_block\n", block_size);
+    result = -1;
+    goto done;
+  }
+
+  fd.ffd = open("/dev/fuse", O_RDWR);
+  if (!fd.ffd) {
+    perror("open /dev/fuse");
+    result = -1;
+    goto done;
+  }
+
+  {
+  char opts[256];
+  snprintf(opts, sizeof(opts),
+          ("fd=%d,user_id=%d,group_id=%d,max_read=%u,"
+           "allow_other,rootmode=040000"),
+           fd.ffd, fd.uid, fd.gid, block_size);
+
+  result = mount("/dev/fuse", FUSE_SIDELOAD_HOST_MOUNTPOINT, "fuse",
+                 MS_NOSUID | MS_NODEV | MS_RDONLY | MS_NOEXEC, opts);
+  if (result < 0) {
+      perror("mount");
+      goto done;
+    }
+  }
+
+  uint8_t request_buffer[sizeof(fuse_in_header) + PATH_MAX * 8];
+  for (;;) {
+    ssize_t len = TEMP_FAILURE_RETRY(read(fd.ffd, request_buffer, sizeof(request_buffer)));
+    if (len == -1) {
+      perror("read request");
+      if (errno == ENODEV) {
+        result = -1;
+        break;
+      }
+      continue;
+    }
+
+    if (static_cast<size_t>(len) < sizeof(fuse_in_header)) {
+      fprintf(stderr, "request too short: len=%zd\n", len);
+      continue;
+    }
+
+    fuse_in_header* hdr = reinterpret_cast<fuse_in_header*>(request_buffer);
+    void* data = request_buffer + sizeof(fuse_in_header);
+
+    result = -ENOSYS;
+
+    switch (hdr->opcode) {
+      case FUSE_INIT:
+        result = handle_init(data, &fd, hdr);
+        break;
+
+      case FUSE_LOOKUP:
+        result = handle_lookup(data, &fd, hdr);
+        break;
+
+      case FUSE_GETATTR:
+        result = handle_getattr(data, &fd, hdr);
+        break;
+
+      case FUSE_OPEN:
+        result = handle_open(data, &fd, hdr);
+        break;
+
+      case FUSE_READ:
+        result = handle_read(data, &fd, hdr);
+        break;
+
+      case FUSE_FLUSH:
+        result = handle_flush(data, &fd, hdr);
+        break;
+
+      case FUSE_RELEASE:
+        result = handle_release(data, &fd, hdr);
+        break;
+
+      default:
+        fprintf(stderr, "unknown fuse request opcode %d\n", hdr->opcode);
+        break;
+    }
+
+    if (result == NO_STATUS_EXIT) {
+      result = 0;
+      break;
+    }
+
+    if (result != NO_STATUS) {
+      fuse_out_header outhdr;
+      outhdr.len = sizeof(outhdr);
+      outhdr.error = result;
+      outhdr.unique = hdr->unique;
+      TEMP_FAILURE_RETRY(write(fd.ffd, &outhdr, sizeof(outhdr)));
+    }
+  }
+
+done:
+  fd.vtab.close();
+
+  if (umount2(mount_point, MNT_DETACH) == -1) {
+    fprintf(stderr, "fuse_sideload umount failed: %s\n", strerror(errno));
+  }
+
+  free(fd.block_data);
+  free(fd.extra_block);
+
+  return result;
+}
+
+extern "C" int run_old_fuse_sideload(const struct provider_vtab& vtab, void* cookie __unused,
+                      uint64_t file_size, uint32_t block_size)
+{
+    return run_fuse_sideload(vtab, file_size, block_size, FUSE_SIDELOAD_HOST_MOUNTPOINT);
+}