/*++ /* NAME /* mail_connect 3 /* SUMMARY /* intra-mail system connection management /* SYNOPSIS /* #include <mail_proto.h> /* /* VSTREAM *mail_connect(class, name, block_mode) /* const char *class; /* const char *name; /* int block_mode; /* /* VSTREAM *mail_connect_wait(class, name) /* const char *class; /* const char *name; /* DESCRIPTION /* This module does low-level connection management for intra-mail /* communication. All reads and writes are subject to a time limit /* (controlled by the global variable \fIvar_ipc_timeout\fR). This /* protects against deadlock conditions that should never happen. /* /* mail_connect() attempts to connect to the UNIX-domain socket of /* the named subsystem. The result is a null pointer in case of failure. /* /* mail_connect_wait() is like mail_connect(), but keeps trying until /* the connection succeeds. However, mail_connect_wait() terminates /* with a fatal error when the service is down. This is to ensure that /* processes terminate when the mail system shuts down. /* /* Arguments: /* .IP class /* Name of a class of local transport channel endpoints, /* either \fIpublic\fR (accessible by any local user) or /* \fIprivate\fR (administrative access only). /* .IP service /* The name of a local transport endpoint within the named class. /* .IP block_mode /* NON_BLOCKING for a non-blocking connection, or BLOCKING. /* SEE ALSO /* timed_ipc(3), enforce IPC timeouts. /* 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 <fcntl.h> #include <unistd.h> #include <stdlib.h> #include <stdarg.h> #include <errno.h> /* Utility library. */ #include <msg.h> #include <vstream.h> #include <connect.h> #include <mymalloc.h> #include <iostuff.h> #include <stringops.h> /* Global library. */ #include "timed_ipc.h" #include "mail_proto.h" /* mail_connect - connect to mail subsystem */ VSTREAM *mail_connect(const char *class, const char *name, int block_mode) { char *path; VSTREAM *stream; int fd; char *sock_name; path = mail_pathname(class, name); if ((fd = LOCAL_CONNECT(path, block_mode, 0)) < 0) { if (msg_verbose) msg_info("connect to subsystem %s: %m", path); stream = 0; } else { if (msg_verbose) msg_info("connect to subsystem %s", path); stream = vstream_fdopen(fd, O_RDWR); timed_ipc_setup(stream); sock_name = concatenate(path, " socket", (char *) 0); vstream_control(stream, VSTREAM_CTL_PATH, sock_name, VSTREAM_CTL_END); myfree(sock_name); } myfree(path); return (stream); } /* mail_connect_wait - connect to mail service until it succeeds */ VSTREAM *mail_connect_wait(const char *class, const char *name) { VSTREAM *stream; int count = 0; /* * XXX Solaris workaround for ECONNREFUSED on a busy socket. */ while ((stream = mail_connect(class, name, BLOCKING)) == 0) { if (count++ >= 10) { msg_fatal("connect #%d to subsystem %s/%s: %m", count, class, name); } else { msg_warn("connect #%d to subsystem %s/%s: %m", count, class, name); } sleep(10); /* XXX make configurable */ } return (stream); }