| /* |
| * Server-side socket communication functions |
| * |
| * Copyright (C) 1998 Alexandre Julliard |
| */ |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <stdarg.h> |
| #include <string.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <sys/uio.h> |
| #include <unistd.h> |
| |
| #include "config.h" |
| #include "object.h" |
| #include "request.h" |
| |
| /* Some versions of glibc don't define this */ |
| #ifndef SCM_RIGHTS |
| #define SCM_RIGHTS 1 |
| #endif |
| |
| /* client structure */ |
| struct client |
| { |
| struct select_user select; /* select user */ |
| unsigned int res; /* current result to send */ |
| int pass_fd; /* fd to pass to and from the client */ |
| struct thread *self; /* client thread (opaque pointer) */ |
| struct timeout_user *timeout; /* current timeout (opaque pointer) */ |
| }; |
| |
| |
| /* socket communication static structures */ |
| static struct iovec myiovec; |
| static struct msghdr msghdr = { NULL, 0, &myiovec, 1, }; |
| #ifndef HAVE_MSGHDR_ACCRIGHTS |
| struct cmsg_fd |
| { |
| int len; /* sizeof structure */ |
| int level; /* SOL_SOCKET */ |
| int type; /* SCM_RIGHTS */ |
| int fd; /* fd to pass */ |
| }; |
| static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 }; |
| #endif /* HAVE_MSGHDR_ACCRIGHTS */ |
| |
| |
| /* send a message to a client that is ready to receive something */ |
| static int do_write( struct client *client ) |
| { |
| int ret; |
| |
| if (client->pass_fd == -1) |
| { |
| ret = write( client->select.fd, &client->res, sizeof(client->res) ); |
| if (ret == sizeof(client->res)) goto ok; |
| } |
| else /* we have an fd to send */ |
| { |
| #ifdef HAVE_MSGHDR_ACCRIGHTS |
| msghdr.msg_accrightslen = sizeof(int); |
| msghdr.msg_accrights = (void *)&client->pass_fd; |
| #else /* HAVE_MSGHDR_ACCRIGHTS */ |
| msghdr.msg_control = &cmsg; |
| msghdr.msg_controllen = sizeof(cmsg); |
| cmsg.fd = client->pass_fd; |
| #endif /* HAVE_MSGHDR_ACCRIGHTS */ |
| |
| myiovec.iov_base = (void *)&client->res; |
| myiovec.iov_len = sizeof(client->res); |
| |
| ret = sendmsg( client->select.fd, &msghdr, 0 ); |
| close( client->pass_fd ); |
| client->pass_fd = -1; |
| if (ret == sizeof(client->res)) goto ok; |
| } |
| if (ret == -1) |
| { |
| if (errno == EWOULDBLOCK) return 0; /* not a fatal error */ |
| if (errno != EPIPE) perror("sendmsg"); |
| } |
| else fprintf( stderr, "Partial message sent %d/%d\n", ret, sizeof(client->res) ); |
| remove_client( client, BROKEN_PIPE ); |
| return 0; |
| |
| ok: |
| set_select_events( &client->select, READ_EVENT ); |
| return 1; |
| } |
| |
| |
| /* read a message from a client that has something to say */ |
| static void do_read( struct client *client ) |
| { |
| int ret; |
| enum request req; |
| |
| #ifdef HAVE_MSGHDR_ACCRIGHTS |
| msghdr.msg_accrightslen = sizeof(int); |
| msghdr.msg_accrights = (void *)&client->pass_fd; |
| #else /* HAVE_MSGHDR_ACCRIGHTS */ |
| msghdr.msg_control = &cmsg; |
| msghdr.msg_controllen = sizeof(cmsg); |
| cmsg.fd = -1; |
| #endif /* HAVE_MSGHDR_ACCRIGHTS */ |
| |
| assert( client->pass_fd == -1 ); |
| |
| myiovec.iov_base = (void *)&req; |
| myiovec.iov_len = sizeof(req); |
| |
| ret = recvmsg( client->select.fd, &msghdr, 0 ); |
| #ifndef HAVE_MSGHDR_ACCRIGHTS |
| client->pass_fd = cmsg.fd; |
| #endif |
| |
| if (ret == sizeof(req)) |
| { |
| int pass_fd = client->pass_fd; |
| client->pass_fd = -1; |
| call_req_handler( client->self, req, pass_fd ); |
| if (pass_fd != -1) close( pass_fd ); |
| return; |
| } |
| if (ret == -1) |
| { |
| perror("recvmsg"); |
| remove_client( client, BROKEN_PIPE ); |
| return; |
| } |
| if (!ret) /* closed pipe */ |
| { |
| remove_client( client, BROKEN_PIPE ); |
| return; |
| } |
| fatal_protocol_error( client->self, "partial message received %d/%d\n", ret, sizeof(req) ); |
| } |
| |
| /* handle a client event */ |
| static void client_event( int event, void *private ) |
| { |
| struct client *client = (struct client *)private; |
| if (event & WRITE_EVENT) do_write( client ); |
| if (event & READ_EVENT) do_read( client ); |
| } |
| |
| /*******************************************************************/ |
| /* server-side exported functions */ |
| |
| /* add a client */ |
| struct client *add_client( int fd, struct thread *self ) |
| { |
| int flags; |
| struct client *client = mem_alloc( sizeof(*client) ); |
| if (!client) return NULL; |
| |
| flags = fcntl( fd, F_GETFL, 0 ); |
| fcntl( fd, F_SETFL, flags | O_NONBLOCK ); |
| |
| client->select.fd = fd; |
| client->select.func = client_event; |
| client->select.private = client; |
| client->self = self; |
| client->timeout = NULL; |
| client->pass_fd = -1; |
| register_select_user( &client->select ); |
| set_select_events( &client->select, READ_EVENT ); |
| return client; |
| } |
| |
| /* remove a client */ |
| void remove_client( struct client *client, int exit_code ) |
| { |
| assert( client ); |
| |
| call_kill_handler( client->self, exit_code ); |
| |
| if (client->timeout) remove_timeout_user( client->timeout ); |
| unregister_select_user( &client->select ); |
| close( client->select.fd ); |
| |
| /* Purge messages */ |
| if (client->pass_fd != -1) close( client->pass_fd ); |
| free( client ); |
| } |
| |
| /* set the fd to pass to the client */ |
| void client_pass_fd( struct client *client, int pass_fd ) |
| { |
| assert( client->pass_fd == -1 ); |
| client->pass_fd = pass_fd; |
| } |
| |
| /* send a reply to a client */ |
| void client_reply( struct client *client, unsigned int res ) |
| { |
| if (debug_level) trace_reply( client->self, res, client->pass_fd ); |
| client->res = res; |
| if (!do_write( client )) set_select_events( &client->select, WRITE_EVENT ); |
| } |