1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <inttypes.h>
18#include <fcntl.h>
19#include <string.h>
20#include <unistd.h>
21
22#include <android-base/unique_fd.h>
23
24#include "LineBuffer.h"
25#include "ProcessMappings.h"
26#include "log.h"
27
28// This function is not re-entrant since it uses a static buffer for
29// the line data.
30bool ProcessMappings(pid_t pid, allocator::vector<Mapping>& mappings) {
31  char map_buffer[1024];
32  snprintf(map_buffer, sizeof(map_buffer), "/proc/%d/maps", pid);
33  android::base::unique_fd fd(open(map_buffer, O_RDONLY));
34  if (fd == -1) {
35    return false;
36  }
37
38  LineBuffer line_buf(fd, map_buffer, sizeof(map_buffer));
39  char* line;
40  size_t line_len;
41  while (line_buf.GetLine(&line, &line_len)) {
42    int name_pos;
43    char perms[5];
44    Mapping mapping{};
45    if (sscanf(line, "%" SCNxPTR "-%" SCNxPTR " %4s %*x %*x:%*x %*d %n",
46        &mapping.begin, &mapping.end, perms, &name_pos) == 3) {
47      if (perms[0] == 'r') {
48        mapping.read = true;
49      }
50      if (perms[1] == 'w') {
51        mapping.write = true;
52      }
53      if (perms[2] == 'x') {
54        mapping.execute = true;
55      }
56      if (perms[3] == 'p') {
57        mapping.priv = true;
58      }
59      if ((size_t)name_pos < line_len) {
60        strlcpy(mapping.name, line + name_pos, sizeof(mapping.name));
61      }
62      mappings.emplace_back(mapping);
63    }
64  }
65  return true;
66}
67