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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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,
#include "SandboxLogging.h"
#ifdef ANDROID
# include <android/log.h>
#endif
#include <algorithm>
#include <stdio.h>
#include <string.h>
#include <sys/uio.h>
#include <unistd.h>
#include "base/posix/eintr_wrapper.h"
#ifdef __GLIBC_PREREQ
# if __GLIBC_PREREQ(2, 32)
# define HAVE_STRERRORNAME_NP 1
# endif
#endif
namespace mozilla {
// Alters an iovec array to remove the first `toDrop` bytes. This
// complexity is necessary because writev can return a short write
// (e.g., if stderr is a pipe and the buffer is almost full).
static void IOVecDrop(struct iovec* iov, int iovcnt, size_t toDrop) {
while (toDrop > 0 && iovcnt > 0) {
size_t toDropHere = std::min(toDrop, iov->iov_len);
iov->iov_base = static_cast<char*>(iov->iov_base) + toDropHere;
iov->iov_len -= toDropHere;
toDrop -= toDropHere;
++iov;
--iovcnt;
}
}
void SandboxLogError(const char* message) {
#ifdef ANDROID
// This uses writev internally and appears to be async signal safe.
__android_log_write(ANDROID_LOG_ERROR, "Sandbox", message);
#endif
static char logPrefixProcess[16];
static const ssize_t printfSize =
::base::strings::SafeSPrintf(logPrefixProcess, "[%d] ", getpid());
static const size_t pidSize =
std::clamp(static_cast<size_t>(printfSize), static_cast<size_t>(0),
static_cast<size_t>(sizeof(logPrefixProcess) - 1));
static const char logPrefix[] = "Sandbox: ", logSuffix[] = "\n";
struct iovec iovs[4] = {
{const_cast<char*>(logPrefixProcess), pidSize},
{const_cast<char*>(logPrefix), sizeof(logPrefix) - 1},
{const_cast<char*>(message), strlen(message)},
{const_cast<char*>(logSuffix), sizeof(logSuffix) - 1},
};
while (iovs[2].iov_len > 0) {
ssize_t written = HANDLE_EINTR(writev(STDERR_FILENO, iovs, 4));
if (written <= 0) {
break;
}
IOVecDrop(iovs, 4, static_cast<size_t>(written));
}
}
ssize_t GetLibcErrorName(char* aBuf, size_t aSize, int aErr) {
const char* errStr;
#ifdef HAVE_STRERRORNAME_NP
// This is the function we'd like to have, but it's a glibc
// extension and present only in newer versions.
errStr = strerrorname_np(aErr);
#else
// Otherwise, handle most of the basic / common errors with a big
// switch statement.
switch (aErr) {
# define HANDLE_ERR(x) \
case x: \
errStr = #x; \
break
// errno-base.h
HANDLE_ERR(EPERM);
HANDLE_ERR(ENOENT);
HANDLE_ERR(ESRCH);
HANDLE_ERR(EINTR);
HANDLE_ERR(EIO);
HANDLE_ERR(ENXIO);
HANDLE_ERR(E2BIG);
HANDLE_ERR(ENOEXEC);
HANDLE_ERR(EBADF);
HANDLE_ERR(ECHILD);
HANDLE_ERR(EAGAIN);
HANDLE_ERR(ENOMEM);
HANDLE_ERR(EACCES);
HANDLE_ERR(EFAULT);
HANDLE_ERR(ENOTBLK);
HANDLE_ERR(EBUSY);
HANDLE_ERR(EEXIST);
HANDLE_ERR(EXDEV);
HANDLE_ERR(ENODEV);
HANDLE_ERR(ENOTDIR);
HANDLE_ERR(EISDIR);
HANDLE_ERR(EINVAL);
HANDLE_ERR(ENFILE);
HANDLE_ERR(EMFILE);
HANDLE_ERR(ENOTTY);
HANDLE_ERR(ETXTBSY);
HANDLE_ERR(EFBIG);
HANDLE_ERR(ENOSPC);
HANDLE_ERR(ESPIPE);
HANDLE_ERR(EROFS);
HANDLE_ERR(EMLINK);
HANDLE_ERR(EPIPE);
HANDLE_ERR(EDOM);
HANDLE_ERR(ERANGE);
// selected other errors
HANDLE_ERR(ENAMETOOLONG);
HANDLE_ERR(ENOSYS);
HANDLE_ERR(ENOTEMPTY);
HANDLE_ERR(ELOOP);
HANDLE_ERR(ENOTSOCK);
HANDLE_ERR(EMSGSIZE);
HANDLE_ERR(ECONNRESET);
HANDLE_ERR(ECONNREFUSED);
HANDLE_ERR(EHOSTUNREACH);
HANDLE_ERR(ESTALE);
# undef HANDLE_ERR
default:
errStr = nullptr;
}
#endif // no strerrorname_np
if (errStr) {
return base::strings::SafeSNPrintf(aBuf, aSize, "%s", errStr);
}
return base::strings::SafeSNPrintf(aBuf, aSize, "error %d", aErr);
}
} // namespace mozilla