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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "LSBUtils.h"
#include <fstream>
#include <string>
#include <string_view>
#include <unistd.h>
#include "base/process_util.h"
#include "mozilla/FileUtils.h"
#include "mozilla/Result.h"
#include "mozilla/ResultVariant.h"
#include "mozilla/ipc/LaunchError.h"
namespace mozilla::widget::lsb {
static const char gLsbReleasePath[] = "/usr/bin/lsb_release";
static const char gEtcOsReleasePath[] = "/etc/os-release";
static const char gUsrOsReleasePath[] = "/usr/lib/os-release";
// See https://www.freedesktop.org/software/systemd/man/latest/os-release.html
bool ExtractAndSetValue(nsACString& aContainer, std::string_view& aValue) {
// We assume the value is well formed and doesn't contain escape characters.
if (aValue.size() > 1 && (aValue.front() == '"' || aValue.front() == '\'')) {
// We assume the quote is properly balanced.
aValue = aValue.substr(1, aValue.size() - 2);
}
aContainer.Assign(aValue.data(), aValue.size());
return !aValue.empty();
}
bool GetOSRelease(nsACString& aDistributor, nsACString& aDescription,
nsACString& aRelease, nsACString& aCodename) {
std::ifstream stream(gEtcOsReleasePath);
if (stream.fail()) {
stream.open(gUsrOsReleasePath);
if (stream.fail()) {
return false;
}
}
bool seen_id = false, seen_pretty_name = false, seen_version_id = false;
std::string rawline;
nsAutoCString name;
nsAutoCString build_id;
while (std::getline(stream, rawline)) {
std::string_view line(rawline);
size_t pos = line.find('=');
if (pos != std::string_view::npos) {
auto key = line.substr(0, pos);
auto value = line.substr(pos + 1);
if (key == "ID") {
if (ExtractAndSetValue(aDistributor, value)) {
// Capitalize the first letter of the id. This mimics what
// lsb_release does on Debian and derivatives. On RH derivatives,
// ID tends to be capitalized already.
char* c = aDistributor.BeginWriting();
if (*c >= 'a' && *c <= 'z') {
*c -= ('a' - 'A');
}
seen_id = true;
}
} else if (key == "NAME") {
ExtractAndSetValue(name, value);
} else if (key == "PRETTY_NAME") {
if (ExtractAndSetValue(aDescription, value)) seen_pretty_name = true;
} else if (key == "VERSION_ID") {
if (ExtractAndSetValue(aRelease, value)) seen_version_id = true;
} else if (key == "BUILD_ID") {
ExtractAndSetValue(build_id, value);
} else if (key == "VERSION_CODENAME") {
ExtractAndSetValue(aCodename, value);
}
}
}
// If NAME is set and only differs from ID in case, use NAME.
if (seen_id && !name.IsEmpty() && name.EqualsIgnoreCase(aDistributor)) {
aDistributor = name;
}
// If VERSION_ID is not set but BUILD_ID is, use BUILD_ID.
if (!seen_version_id && !build_id.IsEmpty()) {
aRelease = build_id;
seen_version_id = true;
}
// Only consider our work done if we've seen at least ID, PRETTY_NAME and
// VERSION_ID.
return seen_id && seen_pretty_name && seen_version_id;
}
bool GetLSBRelease(nsACString& aDistributor, nsACString& aDescription,
nsACString& aRelease, nsACString& aCodename) {
// Nowadays, /etc/os-release is more likely to be available than
// /usr/bin/lsb_release. Relying on the former also avoids forking.
if (GetOSRelease(aDistributor, aDescription, aRelease, aCodename)) {
return true;
}
if (access(gLsbReleasePath, R_OK) != 0) return false;
int pipefd[2];
if (pipe(pipefd) == -1) {
NS_WARNING("pipe() failed!");
return false;
}
std::vector<std::string> argv = {gLsbReleasePath, "-idrc"};
base::LaunchOptions options;
options.fds_to_remap.push_back({pipefd[1], STDOUT_FILENO});
options.wait = true;
base::ProcessHandle process;
Result<Ok, ipc::LaunchError> err = base::LaunchApp(argv, options, &process);
close(pipefd[1]);
if (err.isErr()) {
NS_WARNING("Failed to spawn lsb_release!");
close(pipefd[0]);
return false;
}
ScopedCloseFile stream(fdopen(pipefd[0], "r"));
if (!stream) {
NS_WARNING("Could not wrap fd!");
close(pipefd[0]);
return false;
}
char dist[256], desc[256], release[256], codename[256];
if (fscanf(stream,
"Distributor ID:\t%255[^\n]\n"
"Description:\t%255[^\n]\n"
"Release:\t%255[^\n]\n"
"Codename:\t%255[^\n]\n",
dist, desc, release, codename) != 4) {
NS_WARNING("Failed to parse lsb_release!");
return false;
}
aDistributor.Assign(dist);
aDescription.Assign(desc);
aRelease.Assign(release);
aCodename.Assign(codename);
return true;
}
} // namespace mozilla::widget::lsb
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