diff options
Diffstat (limited to 'login/utmpd/connection.c')
-rw-r--r-- | login/utmpd/connection.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/login/utmpd/connection.c b/login/utmpd/connection.c new file mode 100644 index 0000000000..4e1663189d --- /dev/null +++ b/login/utmpd/connection.c @@ -0,0 +1,180 @@ +/* Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <unistd.h> + +#include "utmpd-private.h" + + +/* Prototypes for the local functions. */ +static client_connection *alloc_connection (void); +static void free_connection (client_connection *connection); +static int set_nonblock_flag (int desc, int value); + + +/* The head of the connection list. */ +static client_connection *connection_list = NULL; + + +/* Accept connection on SOCK, with access permissions given by ACCESS. + Returns a pointer to a newly allocated client_connection if + successful, NULL if not. */ +client_connection * +accept_connection (int sock, int access) +{ + client_connection *connection; + + connection = alloc_connection (); + if (connection == NULL) + return NULL; + + connection->sock = accept (sock, NULL, NULL); + connection->access = access; + if (connection->sock < 0) + { + free_connection (connection); + return NULL; + } + + if (set_nonblock_flag (connection->sock, 1) < 0) + { + close_connection (connection); + return NULL; + } + + return connection; +} + + +/* Close CONNECTION. */ +void +close_connection (client_connection *connection) +{ + close (connection->sock); + free_connection (connection); +} + + +/* Return the connection for SOCK. */ +client_connection * +find_connection (int sock) +{ + client_connection *connection; + + for (connection = connection_list; connection; + connection = connection->next) + { + if (connection->sock == sock) + return connection; + } + + return NULL; +} + + +static client_connection * +alloc_connection (void) +{ + client_connection *connection; + size_t read_bufsize = 1024; + size_t write_bufsize = 1024; + + connection = (client_connection *)malloc (sizeof (client_connection)); + if (connection == NULL) + return NULL; + + memset (connection, 0, sizeof (client_connection)); + + /* Allocate read buffer. */ + connection->read_base = malloc (read_bufsize); + connection->read_ptr = connection->read_base; + connection->read_end = connection->read_base + read_bufsize; + if (connection->read_base == NULL) + { + free (connection); + return NULL; + } + + /* Allocate write buffer. */ + connection->write_base = malloc (write_bufsize); + connection->write_ptr = connection->write_base; + connection->write_end = connection->write_base + write_bufsize; + if (connection->write_base == NULL) + { + free (connection->read_base); + free (connection); + return NULL; + } + + /* Link connection. */ + connection->next = connection_list; + connection_list = connection; + if (connection->next) + connection->next->prev = connection; + + return connection; +} + + +static void +free_connection (client_connection *connection) +{ + /* Unlink connection. */ + if (connection->next) + connection->next->prev = connection->prev; + if (connection->prev) + connection->prev->next = connection->next; + + /* Take care of the head of the list. */ + if (connection == connection_list) + connection_list = connection->next; + + /* Free buffers. */ + if (connection->read_base) + free (connection->read_base); + if (connection->write_base) + free (connection->write_base); + + free (connection); +} + + +/* Set the `O_NONBLOCK' flag of DESC if VALUE is nonzero, + or clear the flag if VALUE is 0. + Return 0 on success, or -1 on error with `errno' set. */ +static int +set_nonblock_flag (int desc, int value) +{ + int oldflags = fcntl (desc, F_GETFL, 0); + /* If reading the flags failed, return error indication now. */ + if (oldflags == -1) + return -1; + /* Set just the flag we want to set. */ + if (value != 0) + oldflags |= O_NONBLOCK; + else + oldflags &= ~O_NONBLOCK; + /* Store modified flag word in the descriptor. */ + return fcntl (desc, F_SETFL, oldflags); +} |