[NaCl SDK] Re-land "Added support for NaCl IO to use the IRT Extension API."

native_client_sdk/src/libraries/nacl_io/kernel_wrap_irt_ext.c

+/* 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. */
+
+/* NACL_IO_IRT_EXT is defined in this header */
+#include "nacl_io/kernel_wrap.h"
+
+/*
+ * The entire file is wrapped in this #if. We do this so this .c file can
+ * always be compiled.
+ */
+#if defined(NACL_IO_IRT_EXT)
+
+#include <assert.h>
+#include <errno.h>
+#include <irt.h>
+#include <irt_dev.h>
+#include <irt_extension.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include "nacl_io/kernel_intercept.h"
+#include "nacl_io/log.h"
+
+/*
+ * The following macros are used to interfact with IRT interfaces.
+ */
+/* This macro defines an interfact structure, use as a regular type. */
+#define NACL_IRT_INTERFACE(interface_type) \
+  struct nacl_io_##interface_type {        \
+    const char *query_string;              \
+    bool queried;                          \
+    bool initialized;                      \
+    struct interface_type interface;       \
+  }
+
+/* This macro unconditionally initializes an interface (do not use directly). */
+#define INIT_INTERFACE_BARE(interface_struct)                   \
+  if (!interface_struct.queried) {                              \
+    const size_t bytes __attribute__((unused)) =                \
+      nacl_interface_query(interface_struct.query_string,       \
+                           &interface_struct.interface,         \
+                           sizeof(interface_struct.interface)); \
+    interface_struct.queried = true;                            \
+    interface_struct.initialized =                              \
+      (bytes == sizeof(interface_struct.interface));            \
+  }
+
+/* This macro initializes an interface and does not handle errors. */
+#define INIT_INTERFACE(interface_struct)   \
+  do {                                     \
+    INIT_INTERFACE_BARE(interface_struct); \
+  } while (false)
+
+/* This macro initializes an interface and returns ENOSYS on failure. */
+#define INIT_INTERFACE_ENOSYS(interface_struct) \
+  do {                                          \
+    INIT_INTERFACE_BARE(interface_struct);      \
+    if (!interface_struct.initialized)          \
+      return ENOSYS;                            \
+  } while (false)
+
+/* This macro initializes an interface and asserts on failure. */
+#define INIT_INTERFACE_ASSERT(interface_struct) \
+  do {                                          \
+    INIT_INTERFACE_BARE(interface_struct);      \
+    assert(interface_struct.initialized);       \
+  } while (false)
+
+/* This macro supplies an IRT Extension interface and asserts on failure. */
+#define EXT_SUPPLY_INTERFACE_ASSERT(interface_struct, supplied_struct) \
+  do {                                                                 \
+    const size_t bytes __attribute__((unused)) =                       \
+      nacl_interface_ext_supply(interface_struct.query_string,         \
+                                &supplied_struct,                      \
+                                sizeof(supplied_struct));              \
+    assert(bytes == sizeof(supplied_struct));                          \
+  } while (false)
+
+/*
+ * IRT interfaces as declared in irt.h.
+ */
+static NACL_IRT_INTERFACE(nacl_irt_basic) s_irt_basic = {
+  NACL_IRT_BASIC_v0_1,
+};
+
+static NACL_IRT_INTERFACE(nacl_irt_fdio) s_irt_fdio = {
+  NACL_IRT_FDIO_v0_1,
+};
+
+static NACL_IRT_INTERFACE(nacl_irt_memory) s_irt_memory = {
+  NACL_IRT_MEMORY_v0_3,
+};
+
+static NACL_IRT_INTERFACE(nacl_irt_resource_open) s_irt_resource_open = {
+  NACL_IRT_RESOURCE_OPEN_v0_1,
+};
+
+/*
+ * IRT Dev interfaces as declared in irt_dev.h.
+ */
+static NACL_IRT_INTERFACE(nacl_irt_dev_fdio) s_irt_dev_fdio = {
+  NACL_IRT_DEV_FDIO_v0_3,
+};
+
+static NACL_IRT_INTERFACE(nacl_irt_dev_filename) s_irt_dev_filename = {
+  NACL_IRT_DEV_FILENAME_v0_3,
+};
+
+static bool s_wrapped = false;
+
+/*
+ * Functions for the nacl_irt_dev_fdio interface.
+ */
+static int ext_close(int fd) {
+  ERRNO_RTN(ki_close(fd));
+}
+
+static int ext_dup(int fd, int *newfd) {
+  *newfd = ki_dup(fd);
+  ERRNO_RTN(*newfd);
+}
+
+static int ext_dup2(int fd, int newfd) {
+  newfd = ki_dup2(fd, newfd);
+  ERRNO_RTN(newfd);
+}
+
+static int ext_read(int fd, void *buf, size_t count, size_t *nread) {
+  ssize_t signed_nread = ki_read(fd, buf, count);
+  *nread = (size_t) signed_nread;
+  ERRNO_RTN(signed_nread);
+}
+
+static int ext_write(int fd, const void *buf, size_t count, size_t *nwrote) {
+  ssize_t signed_nwrote = ki_write(fd, buf, count);
+  *nwrote = (size_t) signed_nwrote;
+  ERRNO_RTN(signed_nwrote);
+}
+
+static int ext_seek(int fd, nacl_irt_off_t offset, int whence,
+                    nacl_irt_off_t *new_offset) {
+  *new_offset = ki_lseek(fd, offset, whence);
+  ERRNO_RTN(*new_offset);
+}
+
+static int ext_fstat(int fd, struct stat *buf) {
+  ERRNO_RTN(ki_fstat(fd, buf));
+}
+
+static int ext_getdents(int fd, struct dirent *ents, size_t count,
+                        size_t *nread) {
+  int rtn = ki_getdents(fd, ents, count);
+  RTN_ERRNO_IF(rtn < 0);
+  *nread = rtn;
+  return 0;
+}
+
+/*
+ * Functions for the nacl_irt_memory interface.
+ */
+static int ext_mmap(void **addr, size_t len, int prot, int flags, int fd,
+                    nacl_irt_off_t off) {
+  if (flags & MAP_ANONYMOUS)
+    return s_irt_memory.interface.mmap(addr, len, prot, flags, fd, off);
+
+  *addr = ki_mmap(*addr, len, prot, flags, fd, off);
+  RTN_ERRNO_IF(*addr == (void*)-1);
+  return 0;
+}
+
+static int ext_munmap(void *addr, size_t length) {
+  /*
+   * Always let the real munmap run on the address range. It is not an error if
+   * there are no mapped pages in that range.
+   */
+  ki_munmap(addr, length);
+  return s_irt_memory.interface.munmap(addr, length);
+}
+
+/*
+ * Extra functions for the nacl_irt_dev_fdio interface.
+ */
+static int ext_fchdir(int fd) {
+  ERRNO_RTN(ki_fchdir(fd));
+}
+
+static int ext_fchmod(int fd, mode_t mode) {
+  ERRNO_RTN(ki_fchmod(fd, mode));
+}
+
+static int ext_fsync(int fd) {
+  ERRNO_RTN(ki_fsync(fd));
+}
+
+static int ext_fdatasync(int fd) {
+  ERRNO_RTN(ki_fdatasync(fd));
+}
+
+static int ext_ftruncate(int fd, nacl_irt_off_t length) {
+  ERRNO_RTN(ki_ftruncate(fd, length));
+}
+
+static int ext_isatty(int fd, int *result) {
+  *result = ki_isatty(fd);
+  RTN_ERRNO_IF(*result == 0);
+  return 0;
+}
+
+/*
+ * Functions for the nacl_irt_dev_filename interface.
+ */
+static int ext_open(const char *pathname, int oflag, mode_t cmode, int *newfd) {
+  *newfd = ki_open(pathname, oflag, cmode);
+  ERRNO_RTN(*newfd);
+}
+
+static int ext_stat(const char *pathname, struct stat *buf) {
+  ERRNO_RTN(ki_stat(pathname, buf));
+}
+
+static int ext_mkdir(const char *pathname, mode_t mode) {
+  ERRNO_RTN(ki_mkdir(pathname, mode));
+}
+
+static int ext_rmdir(const char *pathname) {
+  ERRNO_RTN(ki_rmdir(pathname));
+}
+
+static int ext_chdir(const char *pathname) {
+  ERRNO_RTN(ki_chdir(pathname));
+}
+
+static int ext_getcwd(char *pathname, size_t len) {
+  char *rtn = ki_getcwd(pathname, len);
+  RTN_ERRNO_IF(NULL == rtn);
+  return 0;
+}
+
+static int ext_unlink(const char *pathname) {
+  ERRNO_RTN(ki_unlink(pathname));
+}
+
+static int ext_truncate(const char *pathname, nacl_irt_off_t length) {
+  ERRNO_RTN(ki_truncate(pathname, length));
+}
+
+static int ext_lstat(const char *pathname, struct stat *buf) {
+  ERRNO_RTN(ki_lstat(pathname, buf));
+}
+
+static int ext_link(const char *pathname, const char *newpath) {
+  ERRNO_RTN(ki_link(pathname, newpath));
+}
+
+static int ext_rename(const char *pathname, const char *newpath) {
+  ERRNO_RTN(ki_rename(pathname, newpath));
+}
+
+static int ext_symlink(const char *pathname, const char *newpath) {
+  ERRNO_RTN(ki_symlink(pathname, newpath));
+}
+
+static int ext_chmod(const char *pathname, mode_t mode) {
+  ERRNO_RTN(ki_chmod(pathname, mode));
+}
+
+static int ext_access(const char *pathname, int amode) {
+  ERRNO_RTN(ki_access(pathname, amode));
+}
+
+static int ext_readlink(const char *pathname, char *buf, size_t count,
+                        size_t *nread) {
+  int rtn = ki_readlink(pathname, buf, count);
+  RTN_ERRNO_IF(rtn < 0);
+  *nread = rtn;
+  return 0;
+}
+
+static int ext_utimes(const char *pathname, const struct timeval *times) {
+  ERRNO_RTN(ki_utimes(pathname, times));
+}
+
+/*
+ * Functions declared inside of kernel_wrap_real.h.
+ */
+
+int _real_close(int fd) {
+  INIT_INTERFACE_ENOSYS(s_irt_fdio);
+  return s_irt_fdio.interface.close(fd);
+}
+
+void _real_exit(int status) {
+  INIT_INTERFACE_ASSERT(s_irt_basic);
+  return s_irt_basic.interface.exit(status);
+}
+
+int _real_fstat(int fd, struct stat *buf) {
+  INIT_INTERFACE_ENOSYS(s_irt_fdio);
+  return s_irt_fdio.interface.fstat(fd, buf);
+}
+
+int _real_getdents(int fd, void *nacl_buf, size_t nacl_count, size_t *nread) {
+  INIT_INTERFACE_ENOSYS(s_irt_fdio);
+  return s_irt_fdio.interface.getdents(fd, (struct dirent *) nacl_buf,
+                                       nacl_count, nread);
+}
+
+int _real_isatty(int fd, int *result) {
+  INIT_INTERFACE_ENOSYS(s_irt_dev_fdio);
+  return s_irt_dev_fdio.interface.isatty(fd, result);
+}
+
+int _real_lseek(int fd, int64_t offset, int whence, int64_t *new_offset) {
+  INIT_INTERFACE_ENOSYS(s_irt_fdio);
+  return s_irt_fdio.interface.seek(fd, offset, whence, new_offset);
+}
+
+int _real_mkdir(const char *pathname, mode_t mode) {
+  INIT_INTERFACE_ENOSYS(s_irt_dev_filename);
+  return s_irt_dev_filename.interface.mkdir(pathname, mode);
+}
+
+int _real_mmap(void **addr,
+               size_t length,
+               int prot,
+               int flags,
+               int fd,
+               int64_t offset) {
+  INIT_INTERFACE_ENOSYS(s_irt_memory);
+  return s_irt_memory.interface.mmap(addr, length, prot, flags, fd, offset);
+}
+
+int _real_munmap(void *addr, size_t length) {
+  INIT_INTERFACE_ENOSYS(s_irt_memory);
+  return s_irt_memory.interface.munmap(addr, length);
+}
+
+int _real_open(const char *pathname, int oflag, mode_t mode, int *newfd) {
+  INIT_INTERFACE_ENOSYS(s_irt_dev_filename);
+  return s_irt_dev_filename.interface.open(pathname, oflag, mode, newfd);
+}
+
+int _real_open_resource(const char *file, int *fd) {
+  INIT_INTERFACE_ENOSYS(s_irt_resource_open);
+  return s_irt_resource_open.interface.open_resource(file, fd);
+}
+
+int _real_read(int fd, void *buf, size_t count, size_t *nread) {
+  INIT_INTERFACE_ENOSYS(s_irt_fdio);
+  return s_irt_fdio.interface.read(fd, buf, count, nread);
+}
+
+int _real_rmdir(const char *pathname) {
+  INIT_INTERFACE_ENOSYS(s_irt_dev_filename);
+  return s_irt_dev_filename.interface.rmdir(pathname);
+}
+
+int _real_write(int fd, const void *buf, size_t count, size_t *nwrote) {
+  INIT_INTERFACE_ENOSYS(s_irt_fdio);
+  return s_irt_fdio.interface.write(fd, buf, count, nwrote);
+}
+
+int _real_getcwd(char *pathname, size_t len) {
+  INIT_INTERFACE_ENOSYS(s_irt_dev_filename);
+  return s_irt_dev_filename.interface.getcwd(pathname, len);
+}
+
+/*
+ * Kernel Wrap init/uninit functions declared in kernel_wrap.h.
+ */
+void kernel_wrap_init() {
+  if (!s_wrapped) {
+    LOG_TRACE("kernel_wrap_init");
+
+    /*
+     * Register interfaces as listed in irt.h.
+     */
+
+    /* Register nacl_irt_basic interface. */
+    INIT_INTERFACE_ASSERT(s_irt_basic);
+    struct nacl_irt_basic basic_calls = {
+      ki_exit,
+      s_irt_basic.interface.gettod,
+      s_irt_basic.interface.clock,
+      s_irt_basic.interface.nanosleep,
+      s_irt_basic.interface.sched_yield,
+      s_irt_basic.interface.sysconf,
+    };
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_basic, basic_calls);
+
+    /* Register nacl_irt_fdio interface. */
+    INIT_INTERFACE(s_irt_fdio);
+    struct nacl_irt_fdio fdio = {
+      ext_close,
+      ext_dup,
+      ext_dup2,
+      ext_read,
+      ext_write,
+      ext_seek,
+      ext_fstat,
+      ext_getdents,
+    };
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_fdio, fdio);
+
+    /* Register nacl_irt_memory interface. */
+    INIT_INTERFACE_ASSERT(s_irt_memory);
+    struct nacl_irt_memory mem = {
+      ext_mmap,
+      ext_munmap,
+      s_irt_memory.interface.mprotect,
+    };
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_memory, mem);
+
+    /*
+     * Register interfaces as listed in irt_dev.h.
+     */
+
+    /* Register nacl_irt_dev_fdio interface. */
+    INIT_INTERFACE(s_irt_dev_fdio);
+    struct nacl_irt_dev_fdio dev_fdio = {
+      ext_close,
+      ext_dup,
+      ext_dup2,
+      ext_read,
+      ext_write,
+      ext_seek,
+      ext_fstat,
+      ext_getdents,
+      ext_fchdir,
+      ext_fchmod,
+      ext_fsync,
+      ext_fdatasync,
+      ext_ftruncate,
+      ext_isatty,
+    };
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_dev_fdio, dev_fdio);
+
+    /* Register nacl_irt_dev_filename interface. */
+    INIT_INTERFACE(s_irt_dev_filename);
+    struct nacl_irt_dev_filename dev_filename = {
+      ext_open,
+      ext_stat,
+      ext_mkdir,
+      ext_rmdir,
+      ext_chdir,
+      ext_getcwd,
+      ext_unlink,
+      ext_truncate,
+      ext_lstat,
+      ext_link,
+      ext_rename,
+      ext_symlink,
+      ext_chmod,
+      ext_access,
+      ext_readlink,
+      ext_utimes,
+    };
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_dev_filename, dev_filename);
+
+    s_wrapped = true;
+  }
+}
+
+void kernel_wrap_uninit() {
+  if (s_wrapped) {
+    LOG_TRACE("kernel_wrap_uninit");
+
+    /* Register original IRT interfaces in irt.h. */
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_basic,
+                                s_irt_basic.interface);
+
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_fdio,
+                                s_irt_fdio.interface);
+
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_memory,
+                                s_irt_memory.interface);
+
+    /*
+     * Register optional original IRT dev interfaces in irt_dev.h, these
+     * may or may not exist since they are dev interfaces. If they do not
+     * exist go ahead and supply an empty interface as that's what they
+     * were originally before we supplied any extension interfaces.
+     */
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_dev_fdio,
+                                s_irt_dev_fdio.interface);
+
+    EXT_SUPPLY_INTERFACE_ASSERT(s_irt_dev_filename,
+                                s_irt_dev_filename.interface);
+
+    s_wrapped = false;
+  }
+}
+
+#endif