1/* $NetBSD: unix_listen.c,v 1.2 2017/02/14 01:16:49 christos Exp $ */ 2 3/*++ 4/* NAME 5/* unix_listen 3 6/* SUMMARY 7/* start UNIX-domain listener 8/* SYNOPSIS 9/* #include <listen.h> 10/* 11/* int unix_listen(addr, backlog, block_mode) 12/* const char *addr; 13/* int backlog; 14/* int block_mode; 15/* 16/* int unix_accept(fd) 17/* int fd; 18/* DESCRIPTION 19/* The \fBunix_listen\fR() routine starts a listener in the UNIX domain 20/* on the specified address, with the specified backlog, and returns 21/* the resulting file descriptor. 22/* 23/* unix_accept() accepts a connection and sanitizes error results. 24/* 25/* Arguments: 26/* .IP addr 27/* Null-terminated string with connection destination. 28/* .IP backlog 29/* This argument is passed on to the \fIlisten(2)\fR routine. 30/* .IP block_mode 31/* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for 32/* blocking mode. 33/* .IP fd 34/* File descriptor returned by unix_listen(). 35/* DIAGNOSTICS 36/* Fatal errors: unix_listen() aborts upon any system call failure. 37/* unix_accept() leaves all error handling up to the caller. 38/* LICENSE 39/* .ad 40/* .fi 41/* The Secure Mailer license must be distributed with this software. 42/* AUTHOR(S) 43/* Wietse Venema 44/* IBM T.J. Watson Research 45/* P.O. Box 704 46/* Yorktown Heights, NY 10598, USA 47/*--*/ 48 49/* System interfaces. */ 50 51#include <sys_defs.h> 52#include <sys/socket.h> 53#include <sys/un.h> 54#include <string.h> 55#include <unistd.h> 56#include <sys/stat.h> 57#include <errno.h> 58 59/* Utility library. */ 60 61#include "msg.h" 62#include "iostuff.h" 63#include "listen.h" 64#include "sane_accept.h" 65 66/* unix_listen - create UNIX-domain listener */ 67 68int unix_listen(const char *addr, int backlog, int block_mode) 69{ 70#undef sun 71 struct sockaddr_un sun; 72 ssize_t len = strlen(addr); 73 int sock; 74 75 /* 76 * Translate address information to internal form. 77 */ 78 if (len >= sizeof(sun.sun_path)) 79 msg_fatal("unix-domain name too long: %s", addr); 80 memset((void *) &sun, 0, sizeof(sun)); 81 sun.sun_family = AF_UNIX; 82#ifdef HAS_SUN_LEN 83 sun.sun_len = len + 1; 84#endif 85 memcpy(sun.sun_path, addr, len + 1); 86 87 /* 88 * Create a listener socket. Do whatever we can so we don't run into 89 * trouble when this process is restarted after crash. 90 */ 91 if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 92 msg_fatal("socket: %m"); 93 if (unlink(addr) < 0 && errno != ENOENT) 94 msg_fatal("remove %s: %m", addr); 95 if (bind(sock, (struct sockaddr *) &sun, sizeof(sun)) < 0) 96 msg_fatal("bind: %s: %m", addr); 97#ifdef FCHMOD_UNIX_SOCKETS 98 if (fchmod(sock, 0666) < 0) 99 msg_fatal("fchmod socket %s: %m", addr); 100#else 101 if (chmod(addr, 0666) < 0) 102 msg_fatal("chmod socket %s: %m", addr); 103#endif 104 non_blocking(sock, block_mode); 105 if (listen(sock, backlog) < 0) 106 msg_fatal("listen: %m"); 107 return (sock); 108} 109 110/* unix_accept - accept connection */ 111 112int unix_accept(int fd) 113{ 114 return (sane_accept(fd, (struct sockaddr *) 0, (SOCKADDR_SIZE *) 0)); 115} 116