int32_t NaClSysFstat(struct NaClAppThread *natp,
int d,
uint32_t nasp) {
struct NaClApp *nap = natp->nap;
int32_t retval = -NACL_ABI_EINVAL;
struct NaClDesc *ndp;
struct nacl_abi_stat result;
NaClLog(3,
("Entered NaClSysFstat(0x%08"NACL_PRIxPTR
", %d, 0x%08"NACL_PRIx32")\n"),
(uintptr_t) natp, d, nasp);
ndp = NaClAppGetDesc(nap, d);
if (NULL == ndp) {
NaClLog(4, "bad desc\n");
retval = -NACL_ABI_EBADF;
goto cleanup;
}
retval = (*((struct NaClDescVtbl const *) ndp->base.vtbl)->
Fstat)(ndp, &result);
if (0 == retval) {
if (!NaClFileAccessEnabled()) {
result.nacl_abi_st_ino = NACL_FAKE_INODE_NUM;
}
if (!NaClCopyOutToUser(nap, nasp, &result, sizeof result)) {
retval = -NACL_ABI_EFAULT;
}
}
NaClDescUnref(ndp);
cleanup:
return retval;
}
int32_t NaClSysGetcwd(struct NaClAppThread *natp,
uint32_t buffer,
int len) {
struct NaClApp *nap = natp->nap;
int32_t retval = -NACL_ABI_EINVAL;
char path[NACL_CONFIG_PATH_MAX];
if (!NaClAclBypassChecks) {
retval = -NACL_ABI_EACCES;
goto cleanup;
}
if (len >= NACL_CONFIG_PATH_MAX)
len = NACL_CONFIG_PATH_MAX - 1;
retval = NaClHostDescGetcwd(path, len);
if (retval != 0)
goto cleanup;
if (!NaClCopyOutToUser(nap, buffer, &path, strlen(path) + 1))
retval = -NACL_ABI_EFAULT;
cleanup:
return retval;
}
int32_t NaClSysLstat(struct NaClAppThread *natp,
uint32_t pathname,
uint32_t nasp) {
struct NaClApp *nap = natp->nap;
int32_t retval = -NACL_ABI_EINVAL;
char path[NACL_CONFIG_PATH_MAX];
nacl_host_stat_t stbuf;
NaClLog(3,
("Entered NaClSysLstat(0x%08"NACL_PRIxPTR", 0x%08"NACL_PRIx32","
" 0x%08"NACL_PRIx32")\n"), (uintptr_t) natp, pathname, nasp);
if (!NaClAclBypassChecks) {
return -NACL_ABI_EACCES;
}
retval = CopyPathFromUser(nap, path, sizeof path, pathname);
if (0 != retval)
return retval;
/*
* Perform a host stat.
*/
retval = NaClHostDescLstat(path, &stbuf);
if (0 == retval) {
struct nacl_abi_stat abi_stbuf;
retval = NaClAbiStatHostDescStatXlateCtor(&abi_stbuf, &stbuf);
if (!NaClCopyOutToUser(nap, nasp, &abi_stbuf, sizeof abi_stbuf)) {
return -NACL_ABI_EFAULT;
}
}
return retval;
}
int32_t NaClSysImcMakeBoundSock(struct NaClAppThread *natp,
uint32_t descs_addr) {
/*
* Create a bound socket descriptor and a socket address descriptor.
*/
struct NaClApp *nap = natp->nap;
int32_t retval = -NACL_ABI_EINVAL;
struct NaClDesc *pair[2];
int32_t usr_pair[2];
/* This syscall is not used in Chromium so is disabled by default. */
if (!NaClAclBypassChecks) {
return -NACL_ABI_EACCES;
}
NaClLog(3,
("Entered NaClSysImcMakeBoundSock(0x%08"NACL_PRIxPTR","
" 0x%08"NACL_PRIx32")\n"),
(uintptr_t) natp, descs_addr);
retval = NaClCommonDescMakeBoundSock(pair);
if (0 != retval) {
goto cleanup;
}
usr_pair[0] = NaClAppSetDescAvail(nap, pair[0]);
usr_pair[1] = NaClAppSetDescAvail(nap, pair[1]);
if (!NaClCopyOutToUser(nap, descs_addr, usr_pair, sizeof usr_pair)) {
/*
* NB: The descriptors were briefly observable to untrusted code
* in this window, even though the syscall had not returned yet,
* and another thread which guesses their numbers could actually
* use them, so the NaClDescSafeUnref inside NaClAppSetDesc below
* might not actually deallocate right away. To avoid this, we
* could grab the descriptor lock and hold it until after the
* copyout is done, but that imposes an ordering between the
* descriptor lock and the VM lock which can cause problems
* elsewhere.
*/
NaClAppSetDesc(nap, usr_pair[0], NULL);
NaClAppSetDesc(nap, usr_pair[1], NULL);
retval = -NACL_ABI_EFAULT;
goto cleanup;
}
retval = 0;
cleanup:
return retval;
}
/*
* This implements 64-bit offsets, so we use |offp| as an in/out
* address so we can have a 64 bit return value.
*/
int32_t NaClSysLseek(struct NaClAppThread *natp,
int d,
uint32_t offp,
int whence) {
struct NaClApp *nap = natp->nap;
nacl_abi_off_t offset;
nacl_off64_t retval64;
int32_t retval = -NACL_ABI_EINVAL;
struct NaClDesc *ndp;
NaClLog(3,
("Entered NaClSysLseek(0x%08"NACL_PRIxPTR", %d,"
" 0x%08"NACL_PRIx32", %d)\n"),
(uintptr_t) natp, d, offp, whence);
ndp = NaClAppGetDesc(nap, d);
if (NULL == ndp) {
retval = -NACL_ABI_EBADF;
goto cleanup;
}
if (!NaClCopyInFromUser(nap, &offset, offp, sizeof offset)) {
retval = -NACL_ABI_EFAULT;
goto cleanup_unref;
}
NaClLog(4, "offset 0x%08"NACL_PRIx64"\n", (uint64_t) offset);
retval64 = (*((struct NaClDescVtbl const *) ndp->base.vtbl)->
Seek)(ndp, (nacl_off64_t) offset, whence);
if (NaClOff64IsNegErrno(&retval64)) {
retval = (int32_t) retval64;
} else {
if (NaClCopyOutToUser(nap, offp, &retval64, sizeof retval64)) {
retval = 0;
} else {
NaClLog(LOG_FATAL,
"NaClSysLseek: in/out ptr became invalid at copyout?\n");
}
}
cleanup_unref:
NaClDescUnref(ndp);
cleanup:
return retval;
}
int32_t NaClSysReadlink(struct NaClAppThread *natp,
uint32_t path,
uint32_t buffer,
uint32_t buffer_size) {
struct NaClApp *nap = natp->nap;
char pathname[NACL_CONFIG_PATH_MAX];
char realpath[NACL_CONFIG_PATH_MAX];
int32_t retval = -NACL_ABI_EINVAL;
uint32_t result_size;
if (!NaClAclBypassChecks)
return -NACL_ABI_EACCES;
retval = CopyPathFromUser(nap, pathname, sizeof pathname, path);
if (0 != retval)
return retval;
retval = NaClHostDescReadlink(pathname, realpath, sizeof(realpath));
if (retval < 0)
return retval;
result_size = retval;
CHECK(result_size <= sizeof(realpath)); /* Sanity check */
if (result_size == sizeof(realpath)) {
/*
* The result either got truncated or it fit exactly. Treat it as
* truncation.
*
* We can't distinguish an exact fit from truncation without doing
* another readlink() call. If result_size == buffer_size, we could
* return success here, but there's little point, because untrusted
* code can't distinguish the two either and we don't currently allow
* using a larger buffer.
*/
return -NACL_ABI_ENAMETOOLONG;
}
if (result_size > buffer_size)
result_size = buffer_size;
if (!NaClCopyOutToUser(nap, buffer, realpath, result_size))
return -NACL_ABI_EFAULT;
return result_size;
}
int32_t NaClSysExceptionHandler(struct NaClAppThread *natp,
uint32_t handler_addr,
uint32_t old_handler) {
struct NaClApp *nap = natp->nap;
int32_t rv = -NACL_ABI_EINVAL;
if (!nap->enable_exception_handling) {
rv = -NACL_ABI_ENOSYS;
goto no_lock_exit;
}
if (!NaClIsValidJumpTarget(nap, handler_addr)) {
rv = -NACL_ABI_EFAULT;
goto no_lock_exit;
}
NaClXMutexLock(&nap->exception_mu);
/*
* This needs to be done while holding the lock so that we don't
* start two Windows debug exception handlers.
*/
if (handler_addr != 0) {
if (!NaClDebugExceptionHandlerEnsureAttached(nap)) {
rv = -NACL_ABI_ENOSYS;
goto unlock_exit;
}
}
if (0 != old_handler &&
!NaClCopyOutToUser(nap, (uintptr_t) old_handler,
&nap->exception_handler,
sizeof nap->exception_handler)) {
rv = -NACL_ABI_EFAULT;
goto unlock_exit;
}
nap->exception_handler = handler_addr;
rv = 0;
unlock_exit:
NaClXMutexUnlock(&nap->exception_mu);
no_lock_exit:
return rv;
}
int32_t NaClSysStat(struct NaClAppThread *natp,
const char *pathname,
struct nacl_abi_stat *buf) {
struct NaClApp *nap = natp->nap;
int32_t retval = -NACL_ABI_EINVAL;
char path[NACL_CONFIG_PATH_MAX];
nacl_host_stat_t stbuf;
NaClLog(3,
("Entered NaClSysStat(0x%08"NACL_PRIxPTR", 0x%08"NACL_PRIxPTR","
" 0x%08"NACL_PRIxPTR")\n"),
(uintptr_t) natp, (uintptr_t) pathname, (uintptr_t) buf);
retval = CopyPathFromUser(nap, path, sizeof path, (uintptr_t) pathname);
if (0 != retval)
goto cleanup;
retval = NaClStatAclCheck(nap, path);
if (0 != retval)
goto cleanup;
/*
* Perform a host stat.
*/
retval = NaClHostDescStat(path, &stbuf);
if (0 == retval) {
struct nacl_abi_stat abi_stbuf;
retval = NaClAbiStatHostDescStatXlateCtor(&abi_stbuf,
&stbuf);
if (!NaClCopyOutToUser(nap, (uintptr_t) buf,
&abi_stbuf, sizeof abi_stbuf)) {
retval = -NACL_ABI_EFAULT;
}
}
cleanup:
return retval;
}
int32_t NaClSysImcSocketPair(struct NaClAppThread *natp,
uint32_t descs_out) {
struct NaClApp *nap = natp->nap;
int32_t usr_pair[2];
struct NaClDesc *pair[2];
int32_t retval;
NaClLog(3,
("Entered NaClSysImcSocketPair(0x%08"NACL_PRIxPTR
" 0x%08"NACL_PRIx32")\n"),
(uintptr_t) natp, descs_out);
/* This syscall is not used in Chromium so is disabled by default. */
if (!NaClAclBypassChecks) {
return -NACL_ABI_EACCES;
}
retval = NaClCommonDescSocketPair(pair);
if (0 != retval) {
goto cleanup;
}
usr_pair[0] = NaClAppSetDescAvail(nap, pair[0]);
usr_pair[1] = NaClAppSetDescAvail(nap, pair[1]);
if (!NaClCopyOutToUser(nap, (uintptr_t) descs_out, usr_pair,
sizeof usr_pair)) {
NaClAppSetDesc(nap, usr_pair[0], NULL);
NaClAppSetDesc(nap, usr_pair[1], NULL);
retval = -NACL_ABI_EFAULT;
goto cleanup;
}
retval = 0;
cleanup:
return retval;
}
int32_t NaClSysImcRecvmsg(struct NaClAppThread *natp,
int d,
uint32_t nanimhp,
int flags) {
struct NaClApp *nap = natp->nap;
int32_t retval = -NACL_ABI_EINVAL;
ssize_t ssize_retval;
uintptr_t sysaddr;
size_t i;
struct NaClDesc *ndp;
struct NaClAbiNaClImcMsgHdr kern_nanimh;
struct NaClAbiNaClImcMsgIoVec kern_naiov[NACL_ABI_IMC_IOVEC_MAX];
struct NaClImcMsgIoVec kern_iov[NACL_ABI_IMC_IOVEC_MAX];
int32_t usr_desc[NACL_ABI_IMC_USER_DESC_MAX];
struct NaClImcTypedMsgHdr recv_hdr;
struct NaClDesc *new_desc[NACL_ABI_IMC_DESC_MAX];
nacl_abi_size_t num_user_desc;
struct NaClDesc *invalid_desc = NULL;
NaClLog(3,
("Entered NaClSysImcRecvMsg(0x%08"NACL_PRIxPTR", %d,"
" 0x%08"NACL_PRIx32")\n"),
(uintptr_t) natp, d, nanimhp);
/*
* First, we validate user-supplied message headers before
* allocating a receive buffer.
*/
if (!NaClCopyInFromUser(nap, &kern_nanimh, nanimhp, sizeof kern_nanimh)) {
NaClLog(4, "NaClImcMsgHdr not in user address space\n");
retval = -NACL_ABI_EFAULT;
goto cleanup_leave;
}
/* copy before validating */
if (kern_nanimh.iov_length > NACL_ABI_IMC_IOVEC_MAX) {
NaClLog(4, "gather/scatter array too large: %"NACL_PRIdNACL_SIZE"\n",
kern_nanimh.iov_length);
retval = -NACL_ABI_EINVAL;
goto cleanup_leave;
}
if (kern_nanimh.desc_length > NACL_ABI_IMC_USER_DESC_MAX) {
NaClLog(4, "handle vector too long: %"NACL_PRIdNACL_SIZE"\n",
kern_nanimh.desc_length);
retval = -NACL_ABI_EINVAL;
goto cleanup_leave;
}
if (kern_nanimh.iov_length > 0) {
/*
* Copy IOV array into kernel space. Validate this snapshot and do
* user->kernel address conversions on this snapshot.
*/
if (!NaClCopyInFromUser(nap, kern_naiov, (uintptr_t) kern_nanimh.iov,
(kern_nanimh.iov_length * sizeof kern_naiov[0]))) {
NaClLog(4, "gather/scatter array not in user address space\n");
retval = -NACL_ABI_EFAULT;
goto cleanup_leave;
}
/*
* Convert every IOV base from user to system address, validate
* range of bytes are really in user address space.
*/
for (i = 0; i < kern_nanimh.iov_length; ++i) {
sysaddr = NaClUserToSysAddrRange(nap,
(uintptr_t) kern_naiov[i].base,
kern_naiov[i].length);
if (kNaClBadAddress == sysaddr) {
NaClLog(4, "iov number %"NACL_PRIuS" not entirely in user space\n", i);
retval = -NACL_ABI_EFAULT;
goto cleanup_leave;
}
kern_iov[i].base = (void *) sysaddr;
kern_iov[i].length = kern_naiov[i].length;
}
}
if (kern_nanimh.desc_length > 0) {
sysaddr = NaClUserToSysAddrRange(nap,
(uintptr_t) kern_nanimh.descv,
kern_nanimh.desc_length * sizeof(int32_t));
if (kNaClBadAddress == sysaddr) {
retval = -NACL_ABI_EFAULT;
goto cleanup_leave;
}
}
ndp = NaClAppGetDesc(nap, d);
if (NULL == ndp) {
NaClLog(4, "receiving descriptor invalid\n");
retval = -NACL_ABI_EBADF;
goto cleanup_leave;
}
recv_hdr.iov = kern_iov;
recv_hdr.iov_length = kern_nanimh.iov_length;
recv_hdr.ndescv = new_desc;
recv_hdr.ndesc_length = NACL_ARRAY_SIZE(new_desc);
memset(new_desc, 0, sizeof new_desc);
recv_hdr.flags = 0; /* just to make it obvious; IMC will clear it for us */
/* lock user memory ranges in kern_naiov */
for (i = 0; i < kern_nanimh.iov_length; ++i) {
NaClVmIoWillStart(nap,
kern_naiov[i].base,
kern_naiov[i].base + kern_naiov[i].length - 1);
}
ssize_retval = NACL_VTBL(NaClDesc, ndp)->RecvMsg(ndp, &recv_hdr, flags);
/* unlock user memory ranges in kern_naiov */
for (i = 0; i < kern_nanimh.iov_length; ++i) {
NaClVmIoHasEnded(nap,
kern_naiov[i].base,
kern_naiov[i].base + kern_naiov[i].length - 1);
}
/*
* retval is number of user payload bytes received and excludes the
* header bytes.
*/
NaClLog(3, "NaClSysImcRecvMsg: RecvMsg() returned %"NACL_PRIdS"\n",
ssize_retval);
if (NaClSSizeIsNegErrno(&ssize_retval)) {
/* negative error numbers all have valid 32-bit representations,
* so this cast is safe. */
retval = (int32_t) ssize_retval;
goto cleanup;
} else if (ssize_retval > INT32_MAX || ssize_retval < INT32_MIN) {
retval = -NACL_ABI_EOVERFLOW;
goto cleanup;
} else {
/* cast is safe due to range check above */
retval = (int32_t) ssize_retval;
}
/*
* NB: recv_hdr.flags may contain NACL_ABI_MESSAGE_TRUNCATED and/or
* NACL_ABI_HANDLES_TRUNCATED.
*/
kern_nanimh.flags = recv_hdr.flags;
/*
* Now internalize the NaClHandles as NaClDesc objects.
*/
num_user_desc = recv_hdr.ndesc_length;
if (kern_nanimh.desc_length < num_user_desc) {
kern_nanimh.flags |= NACL_ABI_RECVMSG_DESC_TRUNCATED;
for (i = kern_nanimh.desc_length; i < num_user_desc; ++i) {
NaClDescUnref(new_desc[i]);
new_desc[i] = NULL;
}
num_user_desc = kern_nanimh.desc_length;
}
invalid_desc = (struct NaClDesc *) NaClDescInvalidMake();
/* prepare to write out to user space the descriptor numbers */
for (i = 0; i < num_user_desc; ++i) {
if (invalid_desc == new_desc[i]) {
usr_desc[i] = kKnownInvalidDescNumber;
NaClDescUnref(new_desc[i]);
} else {
usr_desc[i] = NaClAppSetDescAvail(nap, new_desc[i]);
}
new_desc[i] = NULL;
}
if (0 != num_user_desc &&
!NaClCopyOutToUser(nap, (uintptr_t) kern_nanimh.descv, usr_desc,
num_user_desc * sizeof usr_desc[0])) {
NaClLog(LOG_FATAL,
("NaClSysImcRecvMsg: in/out ptr (descv %"NACL_PRIxPTR
") became invalid at copyout?\n"),
(uintptr_t) kern_nanimh.descv);
}
kern_nanimh.desc_length = num_user_desc;
if (!NaClCopyOutToUser(nap, nanimhp, &kern_nanimh, sizeof kern_nanimh)) {
NaClLog(LOG_FATAL,
"NaClSysImcRecvMsg: in/out ptr (iov) became"
" invalid at copyout?\n");
}
/* copy out updated desc count, flags */
cleanup:
if (retval < 0) {
for (i = 0; i < NACL_ARRAY_SIZE(new_desc); ++i) {
if (NULL != new_desc[i]) {
NaClDescUnref(new_desc[i]);
new_desc[i] = NULL;
}
}
}
NaClDescUnref(ndp);
NaClDescSafeUnref(invalid_desc);
NaClLog(3, "NaClSysImcRecvMsg: returning %d\n", retval);
cleanup_leave:
return retval;
}
