blob: 3206764895c060932a61423a223b3ff7ecc0054b [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/sandbox_ipc_linux.h"
#include <fcntl.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include "base/command_line.h"
#include "base/files/scoped_file.h"
#include "base/linux_util.h"
#include "base/macros.h"
#include "base/memory/shared_memory.h"
#include "base/posix/eintr_wrapper.h"
#include "base/posix/unix_domain_socket.h"
#include "base/process/launch.h"
#include "base/strings/string_number_conversions.h"
#include "content/browser/renderer_host/font_utils_linux.h"
#include "content/common/font_config_ipc_linux.h"
#include "content/public/common/content_switches.h"
#include "sandbox/linux/services/libc_interceptor.h"
#include "services/service_manager/sandbox/linux/sandbox_linux.h"
#include "skia/ext/skia_utils_base.h"
#include "third_party/skia/include/ports/SkFontConfigInterface.h"
#include "ui/gfx/font.h"
#include "ui/gfx/font_fallback_linux.h"
#include "ui/gfx/font_render_params.h"
namespace content {
namespace {
SandboxIPCHandler::TestObserver* g_test_observer = nullptr;
// Converts gfx::FontRenderParams::Hinting to WebFontRenderStyle::hintStyle.
// Returns an int for serialization, but the underlying Blink type is a char.
int ConvertHinting(gfx::FontRenderParams::Hinting hinting) {
switch (hinting) {
case gfx::FontRenderParams::HINTING_NONE:
return 0;
case gfx::FontRenderParams::HINTING_SLIGHT:
return 1;
case gfx::FontRenderParams::HINTING_MEDIUM:
return 2;
case gfx::FontRenderParams::HINTING_FULL:
return 3;
}
NOTREACHED() << "Unexpected hinting value " << hinting;
return 0;
}
// Converts gfx::FontRenderParams::SubpixelRendering to
// WebFontRenderStyle::useSubpixelRendering. Returns an int for serialization,
// but the underlying Blink type is a char.
int ConvertSubpixelRendering(
gfx::FontRenderParams::SubpixelRendering rendering) {
switch (rendering) {
case gfx::FontRenderParams::SUBPIXEL_RENDERING_NONE:
return 0;
case gfx::FontRenderParams::SUBPIXEL_RENDERING_RGB:
return 1;
case gfx::FontRenderParams::SUBPIXEL_RENDERING_BGR:
return 1;
case gfx::FontRenderParams::SUBPIXEL_RENDERING_VRGB:
return 1;
case gfx::FontRenderParams::SUBPIXEL_RENDERING_VBGR:
return 1;
}
NOTREACHED() << "Unexpected subpixel rendering value " << rendering;
return 0;
}
} // namespace
// static
void SandboxIPCHandler::SetObserverForTests(
SandboxIPCHandler::TestObserver* observer) {
g_test_observer = observer;
}
SandboxIPCHandler::SandboxIPCHandler(int lifeline_fd, int browser_socket)
: lifeline_fd_(lifeline_fd), browser_socket_(browser_socket) {}
void SandboxIPCHandler::Run() {
struct pollfd pfds[2];
pfds[0].fd = lifeline_fd_;
pfds[0].events = POLLIN;
pfds[1].fd = browser_socket_;
pfds[1].events = POLLIN;
int failed_polls = 0;
for (;;) {
const int r =
HANDLE_EINTR(poll(pfds, arraysize(pfds), -1 /* no timeout */));
// '0' is not a possible return value with no timeout.
DCHECK_NE(0, r);
if (r < 0) {
PLOG(WARNING) << "poll";
if (failed_polls++ == 3) {
LOG(FATAL) << "poll(2) failing. SandboxIPCHandler aborting.";
return;
}
continue;
}
failed_polls = 0;
// The browser process will close the other end of this pipe on shutdown,
// so we should exit.
if (pfds[0].revents) {
break;
}
// If poll(2) reports an error condition in this fd,
// we assume the zygote is gone and we exit the loop.
if (pfds[1].revents & (POLLERR | POLLHUP)) {
break;
}
if (pfds[1].revents & POLLIN) {
HandleRequestFromChild(browser_socket_);
}
}
VLOG(1) << "SandboxIPCHandler stopping.";
}
void SandboxIPCHandler::HandleRequestFromChild(int fd) {
std::vector<base::ScopedFD> fds;
// A FontConfigIPC::METHOD_MATCH message could be kMaxFontFamilyLength
// bytes long (this is the largest message type).
// 128 bytes padding are necessary so recvmsg() does not return MSG_TRUNC
// error for a maximum length message.
char buf[FontConfigIPC::kMaxFontFamilyLength + 128];
const ssize_t len =
base::UnixDomainSocket::RecvMsg(fd, buf, sizeof(buf), &fds);
if (len == -1) {
// TODO: should send an error reply, or the sender might block forever.
if (errno == EMSGSIZE) {
NOTREACHED()
<< "Sandbox host message is larger than kMaxFontFamilyLength";
} else {
PLOG(ERROR) << "Recvmsg failed";
NOTREACHED();
}
return;
}
if (fds.empty())
return;
base::Pickle pickle(buf, len);
base::PickleIterator iter(pickle);
int kind;
if (!iter.ReadInt(&kind))
return;
// Give sandbox first shot at request, if it is not handled, then
// false is returned and we continue on.
if (sandbox::HandleInterceptedCall(kind, fd, iter, fds))
return;
if (kind == FontConfigIPC::METHOD_MATCH) {
HandleFontMatchRequest(fd, iter, fds);
} else if (kind == FontConfigIPC::METHOD_OPEN) {
HandleFontOpenRequest(fd, iter, fds);
} else if (kind ==
service_manager::SandboxLinux::METHOD_GET_FALLBACK_FONT_FOR_CHAR) {
HandleGetFallbackFontForChar(fd, iter, fds);
} else if (kind ==
service_manager::SandboxLinux::METHOD_GET_STYLE_FOR_STRIKE) {
HandleGetStyleForStrike(fd, iter, fds);
} else if (kind ==
service_manager::SandboxLinux::METHOD_MAKE_SHARED_MEMORY_SEGMENT) {
HandleMakeSharedMemorySegment(fd, iter, fds);
} else if (kind ==
service_manager::SandboxLinux::METHOD_MATCH_WITH_FALLBACK) {
HandleMatchWithFallback(fd, iter, fds);
}
}
int SandboxIPCHandler::FindOrAddPath(const SkString& path) {
int count = paths_.size();
for (int i = 0; i < count; ++i) {
if (path == paths_[i])
return i;
}
paths_.emplace_back(path);
return count;
}
void SandboxIPCHandler::HandleFontMatchRequest(
int fd,
base::PickleIterator iter,
const std::vector<base::ScopedFD>& fds) {
SkFontStyle requested_style;
std::string family;
if (!iter.ReadString(&family) ||
!skia::ReadSkFontStyle(&iter, &requested_style))
return;
SkFontConfigInterface::FontIdentity result_identity;
SkString result_family;
SkFontStyle result_style;
SkFontConfigInterface* fc =
SkFontConfigInterface::GetSingletonDirectInterface();
const bool r =
fc->matchFamilyName(family.c_str(), requested_style, &result_identity,
&result_family, &result_style);
base::Pickle reply;
if (!r) {
reply.WriteBool(false);
} else {
// Stash away the returned path, so we can give it an ID (index)
// which will later be given to us in a request to open the file.
int index = FindOrAddPath(result_identity.fString);
result_identity.fID = static_cast<uint32_t>(index);
reply.WriteBool(true);
skia::WriteSkString(&reply, result_family);
skia::WriteSkFontIdentity(&reply, result_identity);
skia::WriteSkFontStyle(&reply, result_style);
}
SendRendererReply(fds, reply, -1);
}
void SandboxIPCHandler::HandleFontOpenRequest(
int fd,
base::PickleIterator iter,
const std::vector<base::ScopedFD>& fds) {
uint32_t index;
if (!iter.ReadUInt32(&index))
return;
if (index >= static_cast<uint32_t>(paths_.size()))
return;
if (g_test_observer) {
g_test_observer->OnFontOpen(index);
}
const int result_fd = open(paths_[index].c_str(), O_RDONLY);
base::Pickle reply;
reply.WriteBool(result_fd != -1);
// The receiver will have its own access to the file, so we will close it
// after this send.
SendRendererReply(fds, reply, result_fd);
if (result_fd >= 0) {
int err = IGNORE_EINTR(close(result_fd));
DCHECK(!err);
}
}
void SandboxIPCHandler::HandleGetFallbackFontForChar(
int fd,
base::PickleIterator iter,
const std::vector<base::ScopedFD>& fds) {
// The other side of this call is
// content/common/child_process_sandbox_support_impl_linux.cc
UChar32 c;
if (!iter.ReadInt(&c))
return;
std::string preferred_locale;
if (!iter.ReadString(&preferred_locale))
return;
auto fallback_font = gfx::GetFallbackFontForChar(c, preferred_locale);
int fontconfig_interface_id =
FindOrAddPath(SkString(fallback_font.filename.data()));
if (g_test_observer) {
g_test_observer->OnGetFallbackFontForChar(c, fallback_font.name,
fontconfig_interface_id);
}
base::Pickle reply;
reply.WriteString(fallback_font.name);
reply.WriteString(fallback_font.filename);
reply.WriteInt(fontconfig_interface_id);
reply.WriteInt(fallback_font.ttc_index);
reply.WriteBool(fallback_font.is_bold);
reply.WriteBool(fallback_font.is_italic);
SendRendererReply(fds, reply, -1);
}
void SandboxIPCHandler::HandleGetStyleForStrike(
int fd,
base::PickleIterator iter,
const std::vector<base::ScopedFD>& fds) {
std::string family;
bool bold;
bool italic;
uint16_t pixel_size;
if (!iter.ReadString(&family) || !iter.ReadBool(&bold) ||
!iter.ReadBool(&italic) || !iter.ReadUInt16(&pixel_size)) {
return;
}
gfx::FontRenderParamsQuery query;
query.families.push_back(family);
query.pixel_size = pixel_size;
query.style = italic ? gfx::Font::ITALIC : 0;
query.weight = bold ? gfx::Font::Weight::BOLD : gfx::Font::Weight::NORMAL;
const gfx::FontRenderParams params = gfx::GetFontRenderParams(query, nullptr);
// These are passed as ints since they're interpreted as tri-state chars in
// Blink.
base::Pickle reply;
reply.WriteInt(params.use_bitmaps);
reply.WriteInt(params.autohinter);
reply.WriteInt(params.hinting != gfx::FontRenderParams::HINTING_NONE);
reply.WriteInt(ConvertHinting(params.hinting));
reply.WriteInt(params.antialiasing);
reply.WriteInt(ConvertSubpixelRendering(params.subpixel_rendering));
reply.WriteInt(params.subpixel_positioning);
SendRendererReply(fds, reply, -1);
}
void SandboxIPCHandler::HandleMakeSharedMemorySegment(
int fd,
base::PickleIterator iter,
const std::vector<base::ScopedFD>& fds) {
base::SharedMemoryCreateOptions options;
uint32_t size;
if (!iter.ReadUInt32(&size))
return;
options.size = size;
if (!iter.ReadBool(&options.executable))
return;
int shm_fd = -1;
base::SharedMemory shm;
if (shm.Create(options))
shm_fd = shm.handle().GetHandle();
base::Pickle reply;
SendRendererReply(fds, reply, shm_fd);
}
void SandboxIPCHandler::HandleMatchWithFallback(
int fd,
base::PickleIterator iter,
const std::vector<base::ScopedFD>& fds) {
std::string face;
bool is_bold;
bool is_italic;
uint32_t charset;
uint32_t fallback_family;
if (!iter.ReadString(&face) || face.empty() || !iter.ReadBool(&is_bold) ||
!iter.ReadBool(&is_italic) || !iter.ReadUInt32(&charset) ||
!iter.ReadUInt32(&fallback_family)) {
return;
}
int font_fd = MatchFontFaceWithFallback(face, is_bold, is_italic, charset,
fallback_family);
base::Pickle reply;
SendRendererReply(fds, reply, font_fd);
if (font_fd >= 0) {
if (IGNORE_EINTR(close(font_fd)) < 0)
PLOG(ERROR) << "close";
}
}
void SandboxIPCHandler::SendRendererReply(
const std::vector<base::ScopedFD>& fds,
const base::Pickle& reply,
int reply_fd) {
struct msghdr msg;
memset(&msg, 0, sizeof(msg));
struct iovec iov = {const_cast<void*>(reply.data()), reply.size()};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
char control_buffer[CMSG_SPACE(sizeof(int))];
if (reply_fd != -1) {
struct stat st;
if (fstat(reply_fd, &st) == 0 && S_ISDIR(st.st_mode)) {
LOG(FATAL) << "Tried to send a directory descriptor over sandbox IPC";
// We must never send directory descriptors to a sandboxed process
// because they can use openat with ".." elements in the path in order
// to escape the sandbox and reach the real filesystem.
}
struct cmsghdr* cmsg;
msg.msg_control = control_buffer;
msg.msg_controllen = sizeof(control_buffer);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
memcpy(CMSG_DATA(cmsg), &reply_fd, sizeof(reply_fd));
msg.msg_controllen = cmsg->cmsg_len;
}
if (HANDLE_EINTR(sendmsg(fds[0].get(), &msg, MSG_DONTWAIT)) < 0)
PLOG(ERROR) << "sendmsg";
}
SandboxIPCHandler::~SandboxIPCHandler() {
if (IGNORE_EINTR(close(lifeline_fd_)) < 0)
PLOG(ERROR) << "close";
if (IGNORE_EINTR(close(browser_socket_)) < 0)
PLOG(ERROR) << "close";
}
} // namespace content