minix/servers/pfs/uds.h

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#ifndef __PFS_UDS_H__
#define __PFS_UDS_H__
/*
* Unix Domain Sockets Implementation (PF_UNIX, PF_LOCAL)
*
* Also See...
*
* dev_uds.c, table.c, uds.c
*/
#include <limits.h>
#include <sys/types.h>
#include <sys/ucred.h>
#include <sys/un.h>
#include <minix/endpoint.h>
/* max connection backlog for incoming connections */
#define UDS_SOMAXCONN 64
typedef void* filp_id_t;
/* ancillary data to be sent */
struct ancillary {
filp_id_t filps[OPEN_MAX];
int fds[OPEN_MAX];
int nfiledes;
struct ucred cred;
};
/*
* Internal State Information for a socket descriptor.
*/
struct uds_fd {
/* Flags */
enum UDS_STATE {
/* This file descriptor is UDS_FREE and can be allocated. */
UDS_FREE = 0,
/* OR it is UDS_INUSE and can't be allocated. */
UDS_INUSE = 1
/* state is set to UDS_INUSE in uds_open(). state is Set to
* UDS_FREE in uds_init() and uds_close(). state should be
* checked prior to all operations.
*/
} state;
/* Owner Info */
/* Socket Owner */
endpoint_t owner;
/* endpoint for suspend/resume */
endpoint_t endpoint;
/* Pipe Housekeeping */
/* inode number on PFS -- each descriptor is backed by 1
* PIPE which is allocated in uds_open() and freed in
* uds_close(). Data is sent/written to a peer's PIPE.
* Data is recv/read from this PIPE.
*/
ino_t inode_nr;
/* position in the PIPE where the data starts */
off_t pos;
/* size of data in the PIPE */
size_t size;
/* control read/write, set by uds_open() and shutdown(2).
* Can be set to S_IRUSR|S_IWUSR, S_IRUSR, S_IWUSR, or 0
* for read and write, read only, write only, or neither.
* default is S_IRUSR|S_IWUSR.
*/
mode_t mode;
/* Socket Info */
/* socket type - SOCK_STREAM, SOCK_DGRAM, or SOCK_SEQPACKET
* Set by uds_ioctl(NWIOSUDSTYPE). It defaults to -1 in
* uds_open(). Any action on a socket with type -1 besides
* uds_ioctl(NWIOSUDSTYPE) and uds_close() will result in
* an error.
*/
int type;
/* queue of pending connections for server sockets.
* connect(2) inserts and accept(2) removes from the queue
*/
int backlog[UDS_SOMAXCONN];
/* requested connection backlog size. Set by listen(2)
* Bounds (0 <= backlog_size <= UDS_SOMAXCONN)
* Defaults to UDS_SOMAXCONN which is defined above.
*/
unsigned char backlog_size;
/* index of peer in uds_fd_table for connected sockets.
* -1 is used to mean no peer. Assumptions: peer != -1 means
* connected.
*/
int peer;
/* index of child (client sd returned by accept(2))
* -1 is used to mean no child.
*/
int child;
/* address -- the address the socket is bound to.
* Assumptions: addr.sun_family == AF_UNIX means its bound.
*/
struct sockaddr_un addr;
/* target -- where DGRAMs are sent to on the next uds_write(). */
struct sockaddr_un target;
/* source -- address where DGRAMs are from. used to fill in the
* from address in recvfrom(2) and recvmsg(2).
*/
struct sockaddr_un source;
/* Flag (1 or 0) - listening for incoming connections.
* Default to 0. Set to 1 by do_listen()
*/
int listening;
/* stores file pointers and credentials being sent between
* processes with sendmsg(2) and recvmsg(2).
*/
struct ancillary ancillary_data;
/* Holds an errno. This is set when a connected socket is
* closed and we need to pass ECONNRESET on to a suspended
* peer.
*/
int err;
/* Suspend/Revive Housekeeping */
/* SUSPEND State Flags */
enum UDS_SUSPENDED {
/* Socket isn't blocked. */
UDS_NOT_SUSPENDED = 0,
/* Socket is blocked on read(2) waiting for data to read. */
UDS_SUSPENDED_READ = 1,
/* Socket is blocked on write(2) for space to write data. */
UDS_SUSPENDED_WRITE = 2,
/* Socket is blocked on connect(2) waiting for the server. */
UDS_SUSPENDED_CONNECT = 4,
/* Socket is blocked on accept(2) waiting for clients. */
UDS_SUSPENDED_ACCEPT = 8
} suspended;
/* Flag (1 or 0) - thing socket was waiting for is ready.
* If 1, then uds_status() will attempt the operation that
* the socket was blocked on.
*/
int ready_to_revive;
/* i/o grant, saved for later use by suspended procs */
cp_grant_id_t io_gr;
/* is of i/o grant, saved for later use by suspended procs */
size_t io_gr_size;
/* Save the call number so that uds_cancel() can unwind the
* call properly.
*/
int call_nr;
/* Save the IOCTL so uds_cancel() knows what got cancelled. */
int ioctl;
/* Flag (1 or 0) - the system call completed.
* A doc I read said DEV_CANCEL might be called even though
* the operation is finished. We use this variable to
* determine if we should rollback the changes or not.
*/
int syscall_done;
/* select() */
/* Flag (1 or 0) - the process blocked on select(2). When
* selecting is 1 and I/O happens on this socket, then
* select_proc should be notified.
*/
int selecting;
/* when a select is in progress, we notify() this endpoint
* of new data.
*/
endpoint_t select_proc;
/* Options (SEL_RD, SEL_WR, SEL_ERR) that are requested. */
int sel_ops_in;
/* Options that are available for this socket. */
int sel_ops_out;
/* Flag (1 or 0) to be set to one before calling notify().
* uds_status() will use the flag to locate this descriptor.
*/
int status_updated;
};
typedef struct uds_fd uds_fd_t;
/* File Descriptor Table -- Defined in uds.c */
EXTERN uds_fd_t uds_fd_table[NR_FDS];
/*
* Take message m and get the index in uds_fd_table.
*/
#define uds_minor(m) (minor((dev_t) m->DEVICE) & BYTE)
/*
* Fill in a reply message.
*/
#define uds_set_reply(msg,type,endpoint,io_gr,status) \
do { \
msg->m_type = type; \
msg->REP_ENDPT = endpoint; \
msg->REP_IO_GRANT = io_gr; \
msg->REP_STATUS = status; \
} while (0)
#endif