/postfix-2.9.3/src/util/inet_listen.c
C | 175 lines | 87 code | 16 blank | 72 comment | 22 complexity | a92f73546aedf72507237cdc4d0f62e4 MD5 | raw file
Possible License(s): IPL-1.0, AGPL-3.0
- /*++
- /* 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
- /*--*/
- /* 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;
- 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,
- (char *) &on, sizeof(on)) < 0)
- msg_fatal("setsockopt(IPV6_V6ONLY): %m");
- # endif
- #endif
- if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
- (char *) &on, sizeof(on)) < 0)
- msg_fatal("setsockopt(SO_REUSEADDR): %m");
- 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));
- }