/*++ /* NAME /* sane_connect 3 /* SUMMARY /* sanitize connect() results /* SYNOPSIS /* #include <sane_connect.h> /* /* int sane_connect(sock, buf, len) /* int sock; /* struct sockaddr *buf; /* SOCKADDR_SIZE *len; /* DESCRIPTION /* sane_connect() implements the connect(2) socket call, and maps /* known harmless error results to EAGAIN. /* BUGS /* Bizarre systems may have other harmless error results. Such /* systems encourage programmers to ignore error results, and /* penalize programmers who code defensively. /* 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 library. */ #include "sys_defs.h" #include <sys/socket.h> #include <errno.h> /* Utility library. */ #include "msg.h" #include "sane_connect.h" /* sane_connect - sanitize connect() results */ int sane_connect(int sock, struct sockaddr * sa, SOCKADDR_SIZE len) { /* * XXX Solaris select() produces false read events, so that read() blocks * forever on a blocking socket, and fails with EAGAIN on a non-blocking * socket. Turning on keepalives will fix a blocking socket provided that * the kernel's keepalive timer expires before the Postfix watchdog * timer. * * XXX Work around NAT induced damage by sending a keepalive before an idle * connection is expired. This requires that the kernel keepalive timer * is set to a short time, like 100s. */ if (sa->sa_family == AF_INET) { int on = 1; (void) setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (char *) &on, sizeof(on)); } return (connect(sock, sa, len)); }