sandboxed-api/sandboxed_api/sandbox2/util/maps_parser.cc

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// Copyright 2019 Google LLC
//
// 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
//
// https://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.
#include "sandboxed_api/sandbox2/util/maps_parser.h"
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "absl/strings/str_split.h"
namespace sandbox2 {
absl::StatusOr<std::vector<MapsEntry>> ParseProcMaps(
const std::string& contents) {
// Note: The format string
// https://github.com/torvalds/linux/blob/v4.14/fs/proc/task_mmu.c#L289
// changed to a non-format string implementation
// (show_vma_header_prefix()).
static constexpr char kFormatString[] =
"%lx-%lx %c%c%c%c %lx %x:%x %lu %1023s";
static constexpr size_t kFilepathLength = 1023;
std::vector<std::string> lines =
absl::StrSplit(contents, '\n', absl::SkipEmpty());
std::vector<MapsEntry> entries;
for (const auto& line : lines) {
MapsEntry entry{};
char r, w, x, s;
entry.path.resize(kFilepathLength + 1, '\0');
int n_matches = sscanf(
line.c_str(), kFormatString, &entry.start, &entry.end, &r, &w, &x, &s,
&entry.pgoff, &entry.major, &entry.minor, &entry.inode, &entry.path[0]);
// Some lines do not have a filename.
if (n_matches == 10) {
entry.path.clear();
} else if (n_matches == 11) {
entry.path.resize(strlen(entry.path.c_str()));
} else {
return absl::FailedPreconditionError("Invalid format");
}
entry.is_readable = r == 'r';
entry.is_writable = w == 'w';
entry.is_executable = x == 'x';
entry.is_shared = s == 's';
entries.push_back(entry);
}
return entries;
}
} // namespace sandbox2