Linux: Add support for chrooted renderers.

skia/ext/SkFontHost_fontconfig_ipc.cpp

+/* libs/graphics/ports/SkFontHost_fontconfig_direct.cpp
+**
+** Copyright 2009, Google Inc.
+**
+** 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
+**
+**     http://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.
+*/
+
+// http://code.google.com/p/chromium/wiki/LinuxSandboxIPC
+
+#include "SkFontHost_fontconfig_ipc.h"
+
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+
+FontConfigIPC::FontConfigIPC(int fd)
+    : fd_(fd) {
+}
+
+FontConfigIPC::~FontConfigIPC() {
+    close(fd_);
+}
+
+static ssize_t SyncIPC(int fd, const struct iovec* output, unsigned output_len,
+                       int* result_fd, const struct iovec* input,
+                       unsigned input_len) {
+    char cmsg_buf[CMSG_SPACE(sizeof(int))];
+
+    int fds[2];
+    if (socketpair(AF_UNIX, SOCK_DGRAM, 0, fds) == -1)
+        return false;
+
+    struct msghdr msg = {0};
+    msg.msg_iov = const_cast<struct iovec*>(input);
+    msg.msg_iovlen = input_len;
+    msg.msg_control = cmsg_buf;
+    msg.msg_controllen = sizeof(cmsg_buf);
+
+    struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg);
+    cmsg->cmsg_level = SOL_SOCKET;
+    cmsg->cmsg_type = SCM_RIGHTS;
+    cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+    *(int *) CMSG_DATA(cmsg) = fds[1];
+    msg.msg_controllen = cmsg->cmsg_len;
+
+    ssize_t r;
+    do {
+      r = sendmsg(fd, &msg, 0);
+    } while (r == -1 && errno == EINTR);
+    close(fds[1]);
+
+    if (r == -1) {
+        close(fds[0]);
+        return -1;
+    }
+
+    memset(&msg, 0, sizeof(msg));

[Lei Zhang, 2009/06/04 01:30:43]

fta reports compile failure. http://paste.ubuntu.com/187812/

needs string.h

+
+    msg.msg_iov = const_cast<struct iovec*>(output);
+    msg.msg_iovlen = output_len;
+    msg.msg_control = cmsg_buf;
+    msg.msg_controllen = sizeof(cmsg_buf);
+
+    do {
+        r = recvmsg(fds[0], &msg, 0);
+    } while (r == -1 && errno == EINTR);
+    close(fds[0]);
+
+    if (r == -1 || msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))
+        return -1;
+
+    cmsg = CMSG_FIRSTHDR(&msg);
+    if (cmsg && cmsg->cmsg_level == SOL_SOCKET &&
+        cmsg->cmsg_type == SCM_RIGHTS) {
+        const int fd = *(int*) CMSG_DATA(cmsg);
+        if (!result_fd)
+            close(fd);
+        *result_fd = fd;
+    }
+
+    return r;
+}
+
+bool FontConfigIPC::Match(std::string* result_family,
+                          unsigned* result_fileid,
+                          bool fileid_valid, unsigned fileid,
+                          const std::string& family, int is_bold,
+                          int is_italic) {
+    MatchRequest request;
+    request.method = METHOD_MATCH;
+    request.fileid_valid = fileid_valid;
+    request.fileid = fileid;
+    request.is_bold = is_bold;
+    request.is_italic = is_italic;
+
+    if (family.size() > 255)
+        return false;
+    request.family_len = family.size();
+
+    struct iovec out_iov[2];
+    out_iov[0].iov_base = &request;
+    out_iov[0].iov_len = sizeof(request);
+    if (family.size()) {
+        out_iov[1].iov_base = const_cast<char*>(family.data());
+        out_iov[1].iov_len = family.size();
+    }
+
+    MatchReply reply;
+    char filename_buf[PATH_MAX];

[Lei Zhang, 2009/06/04 01:30:43]

and limits.h

+
+    struct iovec in_iov[2];
+    in_iov[0].iov_base = &reply;
+    in_iov[0].iov_len = sizeof(reply);
+    in_iov[1].iov_base = filename_buf;
+    in_iov[1].iov_len = sizeof(filename_buf);
+
+    const ssize_t r = SyncIPC(fd_, in_iov, 2, NULL, out_iov,
+                              family.size() ? 2 : 1);
+
+    if (r == -1 || r < sizeof(reply))
+        return false;
+
+    if (reply.result == 0)
+        return false;
+
+    *result_fileid = reply.result_fileid;
+    if (r != sizeof(reply) + reply.filename_len)
+        return false;
+    if (result_family)
+      *result_family = std::string(filename_buf, reply.filename_len);
+
+    return true;
+}
+
+int FontConfigIPC::Open(unsigned fileid) {
+    OpenRequest request;
+    OpenReply reply;
+    const struct iovec out_iov = {&request, sizeof(request)};
+    const struct iovec in_iov = {&reply, sizeof(reply)};
+    int result_fd = -1;
+
+    request.method = METHOD_OPEN;
+    request.fileid = fileid;
+    const ssize_t r = SyncIPC(fd_, &in_iov, 1, &result_fd, &out_iov, 1);
+    if (r == -1 || r != sizeof(reply) || reply.result == 0) {
+        if (result_fd >= 0)
+            close(result_fd);
+        return -1;
+    }
+
+    return result_fd;
+}