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Diffstat (limited to 'src/master/master_listen.c')
| -rw-r--r-- | src/master/master_listen.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/master/master_listen.c b/src/master/master_listen.c new file mode 100644 index 0000000..1e7f6fa --- /dev/null +++ b/src/master/master_listen.c @@ -0,0 +1,186 @@ +/*++ +/* NAME +/* master_listen 3 +/* SUMMARY +/* Postfix master - start/stop listeners +/* SYNOPSIS +/* #include "master.h" +/* +/* void master_listen_init(serv) +/* MASTER_SERV *serv; +/* +/* void master_listen_cleanup(serv) +/* MASTER_SERV *serv; +/* DESCRIPTION +/* master_listen_init() turns on the listener implemented by the +/* named process. FIFOs and UNIX-domain sockets are created with +/* mode 0622 and with ownership mail_owner. +/* +/* master_listen_cleanup() turns off the listener implemented by the +/* named process. +/* DIAGNOSTICS +/* BUGS +/* SEE ALSO +/* inet_listen(3), internet-domain listener +/* unix_listen(3), unix-domain listener +/* fifo_listen(3), named-pipe listener +/* upass_listen(3), file descriptor passing listener +/* set_eugid(3), set effective user/group attributes +/* 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 library. */ + +#include <sys_defs.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <unistd.h> +#include <string.h> + +/* Utility library. */ + +#include <msg.h> +#include <listen.h> +#include <mymalloc.h> +#include <stringops.h> +#include <inet_addr_list.h> +#include <set_eugid.h> +#include <set_ugid.h> +#include <iostuff.h> +#include <myaddrinfo.h> +#include <sock_addr.h> + +/* Global library. */ + +#include <mail_params.h> + +/* Application-specific. */ + +#include "master.h" + +/* master_listen_init - enable connection requests */ + +void master_listen_init(MASTER_SERV *serv) +{ + const char *myname = "master_listen_init"; + char *end_point; + int n; + MAI_HOSTADDR_STR hostaddr; + struct sockaddr *sa; + + /* + * Find out what transport we should use, then create one or more + * listener sockets. Make the listener sockets non-blocking, so that + * child processes don't block in accept() when multiple processes are + * selecting on the same socket and only one of them gets the connection. + */ + switch (serv->type) { + + /* + * UNIX-domain or stream listener endpoints always come as singlets. + */ + case MASTER_SERV_TYPE_UNIX: + set_eugid(var_owner_uid, var_owner_gid); + serv->listen_fd[0] = + LOCAL_LISTEN(serv->name, serv->max_proc > var_proc_limit ? + serv->max_proc : var_proc_limit, NON_BLOCKING); + close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC); + set_ugid(getuid(), getgid()); + break; + + /* + * UNIX-domain datagram listener endpoints always come as singlets. + */ + case MASTER_SERV_TYPE_UXDG: + set_eugid(var_owner_uid, var_owner_gid); + serv->listen_fd[0] = + unix_dgram_listen(serv->name, NON_BLOCKING); + close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC); + set_ugid(getuid(), getgid()); + break; + + /* + * FIFO listener endpoints always come as singlets. + */ + case MASTER_SERV_TYPE_FIFO: + set_eugid(var_owner_uid, var_owner_gid); + serv->listen_fd[0] = fifo_listen(serv->name, 0622, NON_BLOCKING); + close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC); + set_ugid(getuid(), getgid()); + break; + + /* + * INET-domain listener endpoints can be wildcarded (the default) or + * bound to specific interface addresses. + * + * With dual-stack IPv4/6 systems it does not matter, we have to specify + * the addresses anyway, either explicit or wild-card. + */ + case MASTER_SERV_TYPE_INET: + for (n = 0; n < serv->listen_fd_count; n++) { + sa = SOCK_ADDR_PTR(MASTER_INET_ADDRLIST(serv)->addrs + n); + SOCKADDR_TO_HOSTADDR(sa, SOCK_ADDR_LEN(sa), &hostaddr, + (MAI_SERVPORT_STR *) 0, 0); + end_point = concatenate(hostaddr.buf, + ":", MASTER_INET_PORT(serv), (char *) 0); + serv->listen_fd[n] + = inet_listen(end_point, serv->max_proc > var_proc_limit ? + serv->max_proc : var_proc_limit, NON_BLOCKING); + close_on_exec(serv->listen_fd[n], CLOSE_ON_EXEC); + myfree(end_point); + } + break; + + /* + * Descriptor passing endpoints always come as singlets. + */ +#ifdef MASTER_SERV_TYPE_PASS + case MASTER_SERV_TYPE_PASS: + set_eugid(var_owner_uid, var_owner_gid); + serv->listen_fd[0] = + LOCAL_LISTEN(serv->name, serv->max_proc > var_proc_limit ? + serv->max_proc : var_proc_limit, NON_BLOCKING); + close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC); + set_ugid(getuid(), getgid()); + break; +#endif + default: + msg_panic("%s: unknown service type: %d", myname, serv->type); + } +} + +/* master_listen_cleanup - disable connection requests */ + +void master_listen_cleanup(MASTER_SERV *serv) +{ + const char *myname = "master_listen_cleanup"; + int n; + + /* + * XXX The listen socket is shared with child processes. Closing the + * socket in the master process does not really disable listeners in + * child processes. There seems to be no documented way to turn off a + * listener. The 4.4BSD shutdown(2) man page promises an ENOTCONN error + * when shutdown(2) is applied to a socket that is not connected. + */ + for (n = 0; n < serv->listen_fd_count; n++) { + if (close(serv->listen_fd[n]) < 0) + msg_warn("%s: close listener socket %d: %m", + myname, serv->listen_fd[n]); + serv->listen_fd[n] = -1; + } +} |