minix/servers/pfs/dev_uds.c
Thomas Veerman 1ba514e19c UDS: check connection state better
Select(2)ing on UNIX domain sockets was not working properly because
connection state wasn't properly checked/propagated. So selecting for
a read descriptor and closing the write descriptor on the other end
didn't cause select to return. Similarly, read(2) kept blocking while
it should return an error when the other end closed the socket.

Change-Id: I3f5bb52af1a6b03313d508bf915fc838357ba450
2013-03-07 10:49:21 +00:00

1185 lines
29 KiB
C

/*
* Unix Domain Sockets Implementation (PF_UNIX, PF_LOCAL)
* This code handles requests generated by operations on /dev/uds
*
* The entry points into this file are...
*
* uds_open: handles the open(2) syscall on /dev/uds
* uds_close: handles the close(2) syscall on /dev/uds
* uds_select: handles the select(2) syscall on /dev/uds
* uds_read: handles the read(2) syscall on /dev/uds
* uds_write: handles the write(2) syscall on /dev/uds
* uds_ioctl: handles the ioctl(2) syscall on /dev/uds
* uds_status: handles status requests.
* uds_cancel: handles cancelled syscalls.
*
* Also See...
*
* table.c, uds.c, uds.h
*
* Overview
*
* The interface to unix domain sockets is similar to the
* the interface to network sockets. There is a character
* device (/dev/uds) that uses STYLE_CLONE and this server
* is a 'driver' for that device.
*/
#define DEBUG 0
#include "inc.h"
#include "const.h"
#include "glo.h"
#include "uds.h"
static int uds_perform_read(int minor, endpoint_t m_source, size_t
size, int pretend);
static int uds_perform_write(int minor, endpoint_t m_source, size_t
size, int pretend);
int uds_open(message *dev_m_in, message *dev_m_out)
{
message fs_m_in, fs_m_out;
struct ucred ucred;
int rc, i;
int minor;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_open() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x\n", dev_m_in->USER_ENDPT);
#endif
/*
* Find a slot in the descriptor table for the new descriptor.
* The index of the descriptor in the table will be returned.
* Subsequent calls to read/write/close/ioctl/etc will use this
* minor number. The minor number must be different from the
* the /dev/uds device's minor number (currently 0).
*/
minor = -1; /* to trap error */
for (i = 1; i < NR_FDS; i++) {
if (uds_fd_table[i].state == UDS_FREE) {
minor = i;
break;
}
}
if (minor == -1) {
/* descriptor table full */
uds_set_reply(dev_m_out, DEV_OPEN_REPL, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, ENFILE);
return ENFILE;
}
/*
* We found a slot in uds_fd_table, now initialize the descriptor
*/
/* mark this one as 'in use' so that it doesn't get assigned to
* another socket
*/
uds_fd_table[minor].state = UDS_INUSE;
/* track the system call we are performing in case it gets cancelled */
uds_fd_table[minor].call_nr = dev_m_in->m_type;
uds_fd_table[minor].ioctl = 0;
uds_fd_table[minor].syscall_done = 0;
/* set the socket owner */
uds_fd_table[minor].owner = dev_m_in->USER_ENDPT;
uds_fd_table[minor].endpoint = dev_m_in->USER_ENDPT;
/* setup select(2) framework */
uds_fd_table[minor].selecting = 0;
uds_fd_table[minor].select_proc = 0;
uds_fd_table[minor].sel_ops_in = 0;
uds_fd_table[minor].sel_ops_out = 0;
uds_fd_table[minor].status_updated = 0;
/* initialize the data pointer (pos) to the start of the PIPE */
uds_fd_table[minor].pos = 0;
/* the PIPE is initially empty */
uds_fd_table[minor].size = 0;
/* the default for a new socket is to allow reading and writing.
* shutdown(2) will remove one or both flags.
*/
uds_fd_table[minor].mode = S_IRUSR|S_IWUSR;
/* In libc socket(2) sets this to the actual value later with the
* NWIOSUDSTYPE ioctl().
*/
uds_fd_table[minor].type = -1;
/* Clear the backlog by setting each entry to -1 */
for (i = 0; i < UDS_SOMAXCONN; i++) {
/* initially no connections are pending */
uds_fd_table[minor].backlog[i] = -1;
}
memset(&uds_fd_table[minor].ancillary_data, '\0', sizeof(struct
ancillary));
for (i = 0; i < OPEN_MAX; i++) {
uds_fd_table[minor].ancillary_data.fds[i] = -1;
}
/* default the size to UDS_SOMAXCONN */
uds_fd_table[minor].backlog_size = UDS_SOMAXCONN;
/* the socket isn't listening for incoming connections until
* listen(2) is called
*/
uds_fd_table[minor].listening = 0;
/* initially the socket is not connected to a peer */
uds_fd_table[minor].peer = -1;
/* there isn't a child waiting to be accept(2)'d */
uds_fd_table[minor].child = -1;
/* initially the socket is not bound or listening on an address */
memset(&(uds_fd_table[minor].addr), '\0', sizeof(struct sockaddr_un));
memset(&(uds_fd_table[minor].source), '\0', sizeof(struct sockaddr_un));
memset(&(uds_fd_table[minor].target), '\0', sizeof(struct sockaddr_un));
/* Initially the socket isn't suspended. */
uds_fd_table[minor].suspended = UDS_NOT_SUSPENDED;
/* and the socket doesn't have an I/O grant initially */
uds_fd_table[minor].io_gr = (cp_grant_id_t) 0;
/* since there is no I/O grant it effectively has no size either */
uds_fd_table[minor].io_gr_size = 0;
/* The process isn't suspended so we don't flag it as revivable */
uds_fd_table[minor].ready_to_revive = 0;
/* get the effective user id and effective group id from the endpoint */
/* this is needed in the REQ_NEWNODE request to PFS. */
rc = getnucred(uds_fd_table[minor].endpoint, &ucred);
if (rc == -1) {
/* roll back the changes we made to the descriptor */
memset(&(uds_fd_table[minor]), '\0', sizeof(uds_fd_t));
/* likely error: invalid endpoint / proc doesn't exist */
uds_set_reply(dev_m_out, DEV_OPEN_REPL, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, errno);
return errno;
}
/* Prepare Request to the FS side of PFS */
fs_m_in.m_type = REQ_NEWNODE;
fs_m_in.REQ_MODE = I_NAMED_PIPE;
fs_m_in.REQ_DEV = NO_DEV;
fs_m_in.REQ_UID = ucred.uid;
fs_m_in.REQ_GID = ucred.gid;
/* Request a new inode on the pipe file system */
rc = fs_newnode(&fs_m_in, &fs_m_out);
if (rc != OK) {
/* roll back the changes we made to the descriptor */
memset(&(uds_fd_table[minor]), '\0', sizeof(uds_fd_t));
/* likely error: get_block() failed */
uds_set_reply(dev_m_out, DEV_OPEN_REPL, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, rc);
return rc;
}
/* Process the response */
uds_fd_table[minor].inode_nr = fs_m_out.RES_INODE_NR;
/* prepare the reply */
uds_fd_table[minor].syscall_done = 1;
uds_set_reply(dev_m_out, DEV_OPEN_REPL, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, minor);
return minor;
}
int uds_close(message *dev_m_in, message *dev_m_out)
{
int minor;
message fs_m_in, fs_m_out;
int rc;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_close() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x\n", dev_m_in->USER_ENDPT);
#endif
minor = uds_minor(dev_m_in);
if (uds_fd_table[minor].state != UDS_INUSE) {
/* attempted to close a socket that hasn't been opened --
* something is very wrong :(
*/
uds_set_reply(dev_m_out, DEV_CLOSE_REPL, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, EINVAL);
return EINVAL;
}
/* no need to track the syscall in case of cancellation. close() is
* atomic and can't be cancelled. no need to update the endpoint here,
* we won't be needing it to kill the socket
*/
/* if the socket is connected, disconnect it */
if (uds_fd_table[minor].peer != -1) {
int peer = uds_fd_table[minor].peer;
/* set peer of this peer to -1 */
uds_fd_table[peer].peer = -1;
/* error to pass to peer */
uds_fd_table[peer].err = ECONNRESET;
/* if peer was blocked on I/O revive peer */
if (uds_fd_table[peer].suspended) {
uds_fd_table[peer].ready_to_revive = 1;
uds_unsuspend(dev_m_in->m_source, peer);
}
}
if (uds_fd_table[minor].ancillary_data.nfiledes > 0) {
clear_fds(minor, &(uds_fd_table[minor].ancillary_data));
}
/* Prepare Request to the FS side of PFS */
fs_m_in.m_type = REQ_PUTNODE;
fs_m_in.REQ_INODE_NR = uds_fd_table[minor].inode_nr;
fs_m_in.REQ_COUNT = 1;
/* set the socket back to its original UDS_FREE state */
memset(&(uds_fd_table[minor]), '\0', sizeof(uds_fd_t));
/* Request the removal of the inode from the pipe file system */
rc = fs_putnode(&fs_m_in, &fs_m_out);
if (rc != OK) {
perror("fs_putnode");
/* likely error: get_block() failed */
return rc;
}
uds_set_reply(dev_m_out, DEV_CLOSE_REPL, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, OK);
return OK;
}
int uds_select(message *dev_m_in, message *dev_m_out)
{
int i, bytes;
int minor;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_select() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x\n", dev_m_in->USER_ENDPT);
#endif
minor = uds_minor(dev_m_in);
if (uds_fd_table[minor].state != UDS_INUSE) {
/* attempted to close a socket that hasn't been opened --
* something is very wrong :(
*/
uds_sel_reply(dev_m_out, DEV_SEL_REPL1, minor, EINVAL);
return EINVAL;
}
/* setup select(2) framework */
uds_fd_table[minor].selecting = 1;
uds_fd_table[minor].select_proc = dev_m_in->m_source;
/* track the system call we are performing in case it gets cancelled */
uds_fd_table[minor].call_nr = dev_m_in->m_type;
uds_fd_table[minor].ioctl = 0;
uds_fd_table[minor].syscall_done = 0;
/* Can't update the process endpoint here, no info. */
uds_fd_table[minor].sel_ops_in = dev_m_in->USER_ENDPT;
uds_fd_table[minor].sel_ops_out = 0;
/* check if there is data available to read */
bytes = uds_perform_read(minor, dev_m_in->m_source, 1, 1);
if (bytes > 0) {
/* there is data in the pipe for us to read */
uds_fd_table[minor].sel_ops_out |= SEL_RD;
} else if (uds_fd_table[minor].listening == 1) {
/* check for pending connections */
for (i = 0; i < uds_fd_table[minor].backlog_size; i++) {
if (uds_fd_table[minor].backlog[i] != -1) {
uds_fd_table[minor].sel_ops_out |= SEL_RD;
break;
}
}
} else if (bytes != SUSPEND) {
uds_fd_table[minor].sel_ops_out |= SEL_RD;
}
/* check if we can write without blocking */
bytes = uds_perform_write(minor, dev_m_in->m_source, PIPE_BUF, 1);
if (bytes != 0 && bytes != SUSPEND) {
/* There is room to write or there is an error condition */
uds_fd_table[minor].sel_ops_out |= SEL_WR;
}
uds_fd_table[minor].syscall_done = 1;
uds_sel_reply(dev_m_out, DEV_SEL_REPL1, minor,
uds_fd_table[minor].sel_ops_out);
return uds_fd_table[minor].sel_ops_out;
}
static int uds_perform_read(int minor, endpoint_t m_source,
size_t size, int pretend)
{
int rc, peer;
message fs_m_in;
message fs_m_out;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_perform_read() call_count=%d\n", minor,
++call_count);
#endif
peer = uds_fd_table[minor].peer;
if (size <= 0) {
return 0;
}
/* check if we are allowed to read */
if (!(uds_fd_table[minor].mode & S_IRUSR)) {
/* socket is shutdown for reading */
return EPIPE;
}
/* skip reads and writes of 0 (or less!) bytes */
if (uds_fd_table[minor].size == 0) {
if (peer == -1) {
/* We're not connected. That's only a problem when this
* socket is connection oriented. */
if (uds_fd_table[minor].type == SOCK_STREAM ||
uds_fd_table[minor].type == SOCK_SEQPACKET) {
if (uds_fd_table[minor].err == ECONNRESET) {
uds_fd_table[minor].err = 0;
return ECONNRESET;
} else {
return ENOTCONN;
}
}
}
/* Check if process is reading from a closed pipe */
if (peer != -1 && !(uds_fd_table[peer].mode & S_IWUSR) &&
uds_fd_table[minor].size == 0) {
return 0;
}
if (pretend) {
return SUSPEND;
}
/* maybe a process is blocked waiting to write? if
* needed revive the writer
*/
if (peer != -1 && uds_fd_table[peer].suspended) {
uds_fd_table[peer].ready_to_revive = 1;
uds_unsuspend(m_source, peer);
}
#if DEBUG == 1
printf("(uds) [%d] suspending read request\n", minor);
#endif
/* Process is reading from an empty pipe,
* suspend it so some bytes can be written
*/
uds_fd_table[minor].suspended = UDS_SUSPENDED_READ;
return SUSPEND;
}
if (pretend) {
return (size > uds_fd_table[minor].size) ?
uds_fd_table[minor].size : size;
}
/* Prepare Request to the FS side of PFS */
fs_m_in.m_type = REQ_READ;
fs_m_in.REQ_INODE_NR = uds_fd_table[minor].inode_nr;
fs_m_in.REQ_GRANT = uds_fd_table[minor].io_gr;
fs_m_in.REQ_SEEK_POS_HI = 0;
fs_m_in.REQ_SEEK_POS_LO = uds_fd_table[minor].pos;
fs_m_in.REQ_NBYTES = (size > uds_fd_table[minor].size) ?
uds_fd_table[minor].size : size;
/* perform the read */
rc = fs_readwrite(&fs_m_in, &fs_m_out);
if (rc != OK) {
perror("fs_readwrite");
return rc;
}
/* Process the response */
#if DEBUG == 1
printf("(uds) [%d] read complete\n", minor);
#endif
/* move the position of the data pointer up to data we haven't
* read yet
*/
uds_fd_table[minor].pos += fs_m_out.RES_NBYTES;
/* decrease the number of unread bytes */
uds_fd_table[minor].size -= fs_m_out.RES_NBYTES;
/* if we have 0 unread bytes, move the data pointer back to the
* start of the buffer
*/
if (uds_fd_table[minor].size == 0) {
uds_fd_table[minor].pos = 0;
}
/* maybe a big write was waiting for us to read some data, if
* needed revive the writer
*/
if (peer != -1 && uds_fd_table[peer].suspended) {
uds_fd_table[peer].ready_to_revive = 1;
uds_unsuspend(m_source, peer);
}
/* see if peer is blocked on select() and a write is possible
* (from peer to minor)
*/
if (peer != -1 && uds_fd_table[peer].selecting == 1 &&
(uds_fd_table[minor].size+uds_fd_table[minor].pos + 1 < PIPE_BUF)){
/* if the peer wants to know about write being possible
* and it doesn't know about it already, then let the peer know.
*/
if (peer != -1 && (uds_fd_table[peer].sel_ops_in & SEL_WR) &&
!(uds_fd_table[peer].sel_ops_out & SEL_WR)) {
/* a write on peer is possible now */
uds_fd_table[peer].sel_ops_out |= SEL_WR;
uds_fd_table[peer].status_updated = 1;
uds_unsuspend(m_source, peer);
}
}
return fs_m_out.RES_NBYTES; /* return number of bytes read */
}
static int uds_perform_write(int minor, endpoint_t m_source,
size_t size, int pretend)
{
int rc, peer, i;
message fs_m_in;
message fs_m_out;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_perform_write() call_count=%d\n", minor,
++call_count);
#endif
/* skip reads and writes of 0 (or less!) bytes */
if (size <= 0) {
return 0;
}
/* check if we are allowed to write */
if (!(uds_fd_table[minor].mode & S_IWUSR)) {
/* socket is shutdown for writing */
return EPIPE;
}
if (size > PIPE_BUF) {
/* message is too big to ever write to the PIPE */
return EMSGSIZE;
}
if (uds_fd_table[minor].type == SOCK_STREAM ||
uds_fd_table[minor].type == SOCK_SEQPACKET) {
/* if we're writing with a connection oriented socket,
* then it needs a peer to write to
*/
if (uds_fd_table[minor].peer == -1) {
if (uds_fd_table[minor].err == ECONNRESET) {
uds_fd_table[minor].err = 0;
return ECONNRESET;
} else {
return ENOTCONN;
}
} else {
peer = uds_fd_table[minor].peer;
}
} else /* uds_fd_table[minor].type == SOCK_DGRAM */ {
peer = -1;
/* locate the "peer" we want to write to */
for (i = 0; i < NR_FDS; i++) {
/* look for a SOCK_DGRAM socket that is bound on
* the target address
*/
if (uds_fd_table[i].type == SOCK_DGRAM &&
uds_fd_table[i].addr.sun_family == AF_UNIX &&
!strncmp(uds_fd_table[minor].target.sun_path,
uds_fd_table[i].addr.sun_path, UNIX_PATH_MAX)) {
peer = i;
break;
}
}
}
if (peer == -1) {
if (pretend)
return SUSPEND;
return ENOENT;
}
/* check if we write to a closed pipe */
if (!(uds_fd_table[peer].mode & S_IRUSR)) {
return EPIPE;
}
/* check if write would overrun buffer. check if message
* boundry preserving types (SEQPACKET and DGRAM) wouldn't write
* to an empty buffer. check if connectionless sockets have a
* target to write to.
*/
if ((uds_fd_table[peer].pos+uds_fd_table[peer].size+size > PIPE_BUF) ||
((uds_fd_table[minor].type == SOCK_SEQPACKET ||
uds_fd_table[minor].type == SOCK_DGRAM) &&
uds_fd_table[peer].size > 0)) {
if (pretend) {
return SUSPEND;
}
/* if needed revive the reader */
if (uds_fd_table[peer].suspended) {
uds_fd_table[peer].ready_to_revive = 1;
uds_unsuspend(m_source, peer);
}
#if DEBUG == 1
printf("(uds) [%d] suspending write request\n", minor);
#endif
/* Process is reading from an empty pipe,
* suspend it so some bytes can be written
*/
uds_fd_table[minor].suspended = UDS_SUSPENDED_WRITE;
return SUSPEND;
}
if (pretend) {
return size;
}
/* Prepare Request to the FS side of PFS */
fs_m_in.m_type = REQ_WRITE;
fs_m_in.REQ_INODE_NR = uds_fd_table[peer].inode_nr;
fs_m_in.REQ_GRANT = uds_fd_table[minor].io_gr;
fs_m_in.REQ_SEEK_POS_HI = 0;
fs_m_in.REQ_SEEK_POS_LO = uds_fd_table[peer].pos +
uds_fd_table[peer].size;
fs_m_in.REQ_NBYTES = size;
/* Request the write */
rc = fs_readwrite(&fs_m_in, &fs_m_out);
if (rc != OK) {
perror("fs_readwrite");
return rc;
}
/* Process the response */
#if DEBUG == 1
printf("(uds) [%d] write complete\n", minor);
#endif
/* increase the count of unread bytes */
uds_fd_table[peer].size += fs_m_out.RES_NBYTES;
/* fill in the source address to be returned by recvfrom & recvmsg */
if (uds_fd_table[minor].type == SOCK_DGRAM) {
memcpy(&uds_fd_table[peer].source, &uds_fd_table[minor].addr,
sizeof(struct sockaddr_un));
}
/* revive peer that was waiting for us to write */
if (uds_fd_table[peer].suspended) {
uds_fd_table[peer].ready_to_revive = 1;
uds_unsuspend(m_source, peer);
}
/* see if peer is blocked on select()*/
if (uds_fd_table[peer].selecting == 1 && fs_m_out.RES_NBYTES > 0) {
/* if the peer wants to know about data ready to read
* and it doesn't know about it already, then let the peer
* know we have data for it.
*/
if ((uds_fd_table[peer].sel_ops_in & SEL_RD) &&
!(uds_fd_table[peer].sel_ops_out & SEL_RD)) {
/* a read on peer is possible now */
uds_fd_table[peer].sel_ops_out |= SEL_RD;
uds_fd_table[peer].status_updated = 1;
uds_unsuspend(m_source, peer);
}
}
return fs_m_out.RES_NBYTES; /* return number of bytes written */
}
int uds_read(message *dev_m_in, message *dev_m_out)
{
int bytes;
int minor;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_read() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x | Position 0x%x\n", dev_m_in->USER_ENDPT,
dev_m_in->POSITION);
#endif
minor = uds_minor(dev_m_in);
if (uds_fd_table[minor].state != UDS_INUSE) {
/* attempted to close a socket that hasn't been opened --
* something is very wrong :(
*/
uds_set_reply(dev_m_out, DEV_REVIVE, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, EINVAL);
return EINVAL;
}
/* track the system call we are performing in case it gets cancelled */
uds_fd_table[minor].call_nr = dev_m_in->m_type;
uds_fd_table[minor].ioctl = 0;
uds_fd_table[minor].syscall_done = 0;
/* Update the process endpoint. */
uds_fd_table[minor].endpoint = dev_m_in->USER_ENDPT;
/* setup select(2) framework */
uds_fd_table[minor].selecting = 0;
/* save I/O Grant info */
uds_fd_table[minor].io_gr = (cp_grant_id_t) dev_m_in->IO_GRANT;
uds_fd_table[minor].io_gr_size = dev_m_in->COUNT;
bytes = uds_perform_read(minor, dev_m_in->m_source,
uds_fd_table[minor].io_gr_size, 0);
uds_set_reply(dev_m_out, DEV_REVIVE, uds_fd_table[minor].endpoint,
uds_fd_table[minor].io_gr, bytes);
return bytes;
}
int uds_write(message *dev_m_in, message *dev_m_out)
{
int bytes;
int minor;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_write() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x | Position 0x%x\n", dev_m_in->USER_ENDPT,
dev_m_in->POSITION);
#endif
minor = uds_minor(dev_m_in);
if (uds_fd_table[minor].state != UDS_INUSE) {
/* attempted to write to a socket that hasn't been opened --
* something is very wrong :(
*/
uds_set_reply(dev_m_out, DEV_REVIVE, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, EINVAL);
return EINVAL;
}
/* track the system call we are performing in case it gets cancelled */
uds_fd_table[minor].call_nr = dev_m_in->m_type;
uds_fd_table[minor].ioctl = 0;
uds_fd_table[minor].syscall_done = 0;
/* Update the process endpoint. */
uds_fd_table[minor].endpoint = dev_m_in->USER_ENDPT;
/* setup select(2) framework */
uds_fd_table[minor].selecting = 0;
/* save I/O Grant info */
uds_fd_table[minor].io_gr = (cp_grant_id_t) dev_m_in->IO_GRANT;
uds_fd_table[minor].io_gr_size = dev_m_in->COUNT;
bytes = uds_perform_write(minor, dev_m_in->m_source,
uds_fd_table[minor].io_gr_size, 0);
uds_set_reply(dev_m_out, DEV_REVIVE, uds_fd_table[minor].endpoint,
uds_fd_table[minor].io_gr, bytes);
return bytes;
}
int uds_ioctl(message *dev_m_in, message *dev_m_out)
{
int rc, minor;
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_ioctl() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x | Position 0x%x\n", dev_m_in->USER_ENDPT,
dev_m_in->POSITION);
#endif
minor = uds_minor(dev_m_in);
if (uds_fd_table[minor].state != UDS_INUSE) {
/* attempted to close a socket that hasn't been opened --
* something is very wrong :(
*/
uds_set_reply(dev_m_out, DEV_REVIVE, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, EINVAL);
return EINVAL;
}
/* track the system call we are performing in case it gets cancelled */
uds_fd_table[minor].call_nr = dev_m_in->m_type;
uds_fd_table[minor].ioctl = dev_m_in->COUNT;
uds_fd_table[minor].syscall_done = 0;
/* setup select(2) framework */
uds_fd_table[minor].selecting = 0;
/* update the owner endpoint - yes it's really stored in POSITION */
uds_fd_table[minor].owner = dev_m_in->POSITION;
switch (dev_m_in->COUNT) { /* Handle the ioctl(2) command */
case NWIOSUDSCONN:
/* connect to a listening socket -- connect() */
rc = do_connect(dev_m_in, dev_m_out);
break;
case NWIOSUDSACCEPT:
/* accept an incoming connection -- accept() */
rc = do_accept(dev_m_in, dev_m_out);
break;
case NWIOSUDSBLOG:
/* set the backlog_size and put the socket into the
* listening state -- listen()
*/
rc = do_listen(dev_m_in, dev_m_out);
break;
case NWIOSUDSTYPE:
/* set the type for this socket (i.e.
* SOCK_STREAM, SOCK_DGRAM, etc) -- socket()
*/
rc = do_socket(dev_m_in, dev_m_out);
break;
case NWIOSUDSADDR:
/* set the address for this socket -- bind() */
rc = do_bind(dev_m_in, dev_m_out);
break;
case NWIOGUDSADDR:
/* get the address for this socket -- getsockname() */
rc = do_getsockname(dev_m_in, dev_m_out);
break;
case NWIOGUDSPADDR:
/* get the address for the peer -- getpeername() */
rc = do_getpeername(dev_m_in, dev_m_out);
break;
case NWIOSUDSSHUT:
/* shutdown a socket for reading, writing, or
* both -- shutdown()
*/
rc = do_shutdown(dev_m_in, dev_m_out);
break;
case NWIOSUDSPAIR:
/* connect two sockets -- socketpair() */
rc = do_socketpair(dev_m_in, dev_m_out);
break;
case NWIOGUDSSOTYPE:
/* get socket type -- getsockopt(SO_TYPE) */
rc = do_getsockopt_sotype(dev_m_in, dev_m_out);
break;
case NWIOGUDSPEERCRED:
/* get peer endpoint -- getsockopt(SO_PEERCRED) */
rc = do_getsockopt_peercred(dev_m_in, dev_m_out);
break;
case NWIOSUDSTADDR:
/* set target address -- sendto() */
rc = do_sendto(dev_m_in, dev_m_out);
break;
case NWIOGUDSFADDR:
/* get from address -- recvfrom() */
rc = do_recvfrom(dev_m_in, dev_m_out);
break;
case NWIOGUDSSNDBUF:
/* get the send buffer size -- getsockopt(SO_SNDBUF) */
rc = do_getsockopt_sndbuf(dev_m_in, dev_m_out);
break;
case NWIOSUDSSNDBUF:
/* set the send buffer size -- setsockopt(SO_SNDBUF) */
rc = do_setsockopt_sndbuf(dev_m_in, dev_m_out);
break;
case NWIOGUDSRCVBUF:
/* get the send buffer size -- getsockopt(SO_SNDBUF) */
rc = do_getsockopt_rcvbuf(dev_m_in, dev_m_out);
break;
case NWIOSUDSRCVBUF:
/* set the send buffer size -- setsockopt(SO_SNDBUF) */
rc = do_setsockopt_rcvbuf(dev_m_in, dev_m_out);
break;
case NWIOSUDSCTRL:
/* set the control data -- sendmsg() */
rc = do_sendmsg(dev_m_in, dev_m_out);
break;
case NWIOGUDSCTRL:
/* set the control data -- recvmsg() */
rc = do_recvmsg(dev_m_in, dev_m_out);
break;
default:
/* the IOCTL command is not valid for /dev/uds --
* this happens a lot and is normal. a lot of
* libc functions determine the socket type with
* IOCTLs. Any not for us simply get a EBADIOCTL
* response.
*/
rc = EBADIOCTL;
}
if (rc != SUSPEND)
uds_fd_table[minor].syscall_done = 1;
uds_set_reply(dev_m_out, DEV_REVIVE, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, rc);
return rc;
}
int uds_unsuspend(endpoint_t m_source, int minor)
{
int r = OK, bytes;
message m_out;
uds_fd_t *fdp;
fdp = &uds_fd_table[minor];
if (fdp->status_updated == 1) {
/* clear the status_updated flag */
fdp->status_updated = 0;
fdp->selecting = 0;
/* prepare the response */
uds_sel_reply(&m_out, DEV_SEL_REPL2, minor, fdp->sel_ops_out);
} else if (fdp->ready_to_revive == 1) {
/* clear the ready to revive flag */
fdp->ready_to_revive = 0;
switch (fdp->suspended) {
case UDS_SUSPENDED_READ:
bytes = uds_perform_read(minor, m_source,
fdp->io_gr_size, 0);
if (bytes == SUSPEND) {
r = SUSPEND;
break;
}
fdp->suspended = UDS_NOT_SUSPENDED;
uds_set_reply(&m_out, DEV_REVIVE, fdp->endpoint,
fdp->io_gr, bytes);
break;
case UDS_SUSPENDED_WRITE:
bytes = uds_perform_write(minor, m_source,
fdp->io_gr_size, 0);
if (bytes == SUSPEND) {
r = SUSPEND;
break;
}
fdp->suspended = UDS_NOT_SUSPENDED;
uds_set_reply(&m_out, DEV_REVIVE, fdp->endpoint,
fdp->io_gr, bytes);
break;
case UDS_SUSPENDED_CONNECT:
case UDS_SUSPENDED_ACCEPT:
/* In both cases, the process
* that send the notify()
* already performed the connection.
* The only thing to do here is
* unblock.
*/
fdp->suspended = UDS_NOT_SUSPENDED;
uds_set_reply(&m_out, DEV_REVIVE, fdp->endpoint,
fdp->io_gr, OK);
break;
default:
return(OK);
}
}
if (r == OK) reply(m_source, &m_out);
return(r);
}
int uds_cancel(message *dev_m_in, message *dev_m_out)
{
int i, j;
int minor;
/* XXX: should become a noop? */
#if DEBUG == 1
static int call_count = 0;
printf("(uds) [%d] uds_cancel() call_count=%d\n", uds_minor(dev_m_in),
++call_count);
printf("Endpoint: 0x%x\n", dev_m_in->USER_ENDPT);
#endif
minor = uds_minor(dev_m_in);
if (uds_fd_table[minor].state != UDS_INUSE) {
/* attempted to close a socket that hasn't been opened --
* something is very wrong :(
*/
uds_set_reply(dev_m_out, DEV_NO_STATUS, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, EINVAL);
return EINVAL;
}
/* Update the process endpoint. */
uds_fd_table[minor].endpoint = dev_m_in->USER_ENDPT;
/* setup select(2) framework */
uds_fd_table[minor].selecting = 0;
/* the system call was cancelled, so if the socket was suspended
* (which is likely the case), then it is not suspended anymore.
*/
uds_fd_table[minor].suspended = UDS_NOT_SUSPENDED;
/* If there is a system call and it isn't complete, roll back */
if (uds_fd_table[minor].call_nr && !uds_fd_table[minor].syscall_done) {
if (uds_fd_table[minor].call_nr == DEV_IOCTL_S) {
switch (uds_fd_table[minor].ioctl) {
case NWIOSUDSACCEPT: /* accept() */
/* partial accept() only changes
* uds_fd_table[minorparent].child
*/
for (i = 0; i < NR_FDS; i++) {
if (uds_fd_table[i].child ==
minor) {
uds_fd_table[i].child = -1;
}
}
break;
case NWIOSUDSCONN: /* connect() */
/* partial connect() sets addr
* and adds minor to server backlog
*/
for (i = 0; i < NR_FDS; i++) {
/* find a socket that is in
* use.
*/
if (uds_fd_table[i].state ==
UDS_INUSE) {
/* see if minor is in
* the backlog
*/
for (j = 0; j < uds_fd_table[i].backlog_size; j++) {
if (uds_fd_table[i].backlog[j] == minor) {
/* remove from backlog */
uds_fd_table[i].backlog[j] = -1;
}
}
}
}
/* clear the address */
memset(&(uds_fd_table[minor].addr),
'\0',
sizeof(struct sockaddr_un));
break;
case NWIOSUDSTADDR: /* sendto() */
case NWIOSUDSADDR: /* bind() */
case NWIOGUDSADDR: /* getsockname() */
case NWIOGUDSPADDR: /* getpeername() */
case NWIOSUDSTYPE: /* socket() */
case NWIOSUDSBLOG: /* listen() */
case NWIOSUDSSHUT: /* shutdown() */
case NWIOSUDSPAIR: /* socketpair() */
case NWIOGUDSSOTYPE: /* SO_TYPE */
case NWIOGUDSPEERCRED: /* SO_PEERCRED */
default:
/* these are atomic, never suspend,
* and can't be cancelled once called
*/
break;
}
}
/* DEV_READ_S or DEV_WRITE_S don't need to do anything
* when cancelled. DEV_OPEN, DEV_REOPEN, DEV_SELECT,
* DEV_CLOSE are atomic, never suspend, and can't
* be cancelled once called.
*/
uds_fd_table[minor].syscall_done = 1;
}
uds_set_reply(dev_m_out, DEV_NO_STATUS, dev_m_in->USER_ENDPT,
(cp_grant_id_t) dev_m_in->IO_GRANT, EINTR);
return EINTR;
}