diff options
Diffstat (limited to 'src/util/inet_listen.c')
| -rw-r--r-- | src/util/inet_listen.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/util/inet_listen.c b/src/util/inet_listen.c new file mode 100644 index 0000000..31800cd --- /dev/null +++ b/src/util/inet_listen.c @@ -0,0 +1,189 @@ +/*++ +/* NAME +/* inet_listen 3 +/* SUMMARY +/* start TCP listener +/* SYNOPSIS +/* #include <listen.h> +/* +/* int inet_windowsize; +/* +/* int inet_listen(addr, backlog, block_mode) +/* const char *addr; +/* int backlog; +/* int block_mode; +/* +/* int inet_accept(fd) +/* int fd; +/* DESCRIPTION +/* The \fBinet_listen\fR routine starts a TCP listener +/* on the specified address, with the specified backlog, and returns +/* the resulting file descriptor. +/* +/* inet_accept() accepts a connection and sanitizes error results. +/* +/* Specify an inet_windowsize value > 0 to override the TCP +/* window size that the server advertises to the client. +/* +/* Arguments: +/* .IP addr +/* The communication endpoint to listen on. The syntax is "host:port". +/* Host and port may be specified in symbolic form or numerically. +/* A null host field means listen on all network interfaces. +/* .IP backlog +/* This argument is passed on to the \fIlisten(2)\fR routine. +/* .IP block_mode +/* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for +/* blocking mode. +/* .IP fd +/* File descriptor returned by inet_listen(). +/* DIAGNOSTICS +/* Fatal errors: inet_listen() aborts upon any system call failure. +/* inet_accept() leaves all error handling up to the caller. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System libraries. */ + +#include <sys_defs.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <netdb.h> +#ifndef MAXHOSTNAMELEN +#include <sys/param.h> +#endif +#include <errno.h> +#include <string.h> +#include <unistd.h> + +/* Utility library. */ + +#include "mymalloc.h" +#include "msg.h" +#include "host_port.h" +#include "iostuff.h" +#include "listen.h" +#include "sane_accept.h" +#include "myaddrinfo.h" +#include "sock_addr.h" +#include "inet_proto.h" + +/* inet_listen - create TCP listener */ + +int inet_listen(const char *addr, int backlog, int block_mode) +{ + struct addrinfo *res; + struct addrinfo *res0; + int aierr; + int sock; + int on = 1; + char *buf; + char *host; + char *port; + const char *parse_err; + MAI_HOSTADDR_STR hostaddr; + MAI_SERVPORT_STR portnum; + const INET_PROTO_INFO *proto_info; + + /* + * Translate address information to internal form. + */ + buf = mystrdup(addr); + if ((parse_err = host_port(buf, &host, "", &port, (char *) 0)) != 0) + msg_fatal("%s: %s", addr, parse_err); + if (*host == 0) + host = 0; + if ((aierr = hostname_to_sockaddr(host, port, SOCK_STREAM, &res0)) != 0) + msg_fatal("%s: %s", addr, MAI_STRERROR(aierr)); + myfree(buf); + /* No early returns or res0 leaks. */ + + proto_info = inet_proto_info(); + for (res = res0; /* see below */ ; res = res->ai_next) { + + /* + * No usable address found. + */ + if (res == 0) + msg_fatal("%s: host found but no usable address", addr); + + /* + * Safety net. + */ + if (strchr((char *) proto_info->sa_family_list, res->ai_family) != 0) + break; + + msg_info("skipping address family %d for %s", res->ai_family, addr); + } + + /* + * Show what address we're trying. + */ + if (msg_verbose) { + SOCKADDR_TO_HOSTADDR(res->ai_addr, res->ai_addrlen, + &hostaddr, &portnum, 0); + msg_info("trying... [%s]:%s", hostaddr.buf, portnum.buf); + } + + /* + * Create a listener socket. + */ + if ((sock = socket(res->ai_family, res->ai_socktype, 0)) < 0) + msg_fatal("socket: %m"); +#ifdef HAS_IPV6 +#if defined(IPV6_V6ONLY) && !defined(BROKEN_AI_PASSIVE_NULL_HOST) + if (res->ai_family == AF_INET6 + && setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, + (void *) &on, sizeof(on)) < 0) + msg_fatal("setsockopt(IPV6_V6ONLY): %m"); +#endif +#endif + if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, + (void *) &on, sizeof(on)) < 0) + msg_fatal("setsockopt(SO_REUSEADDR): %m"); +#if defined(SO_REUSEPORT_LB) + if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT_LB, + (void *) &on, sizeof(on)) < 0) + msg_fatal("setsockopt(SO_REUSEPORT_LB): %m"); +#elif defined(SO_REUSEPORT) + if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, + (void *) &on, sizeof(on)) < 0) + msg_fatal("setsockopt(SO_REUSEPORT): %m"); +#endif + if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { + SOCKADDR_TO_HOSTADDR(res->ai_addr, res->ai_addrlen, + &hostaddr, &portnum, 0); + msg_fatal("bind %s port %s: %m", hostaddr.buf, portnum.buf); + } + freeaddrinfo(res0); + non_blocking(sock, block_mode); + if (inet_windowsize > 0) + set_inet_windowsize(sock, inet_windowsize); + if (listen(sock, backlog) < 0) + msg_fatal("listen: %m"); + return (sock); +} + +/* inet_accept - accept connection */ + +int inet_accept(int fd) +{ + struct sockaddr_storage ss; + SOCKADDR_SIZE ss_len = sizeof(ss); + + return (sane_accept(fd, (struct sockaddr *) &ss, &ss_len)); +} |