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Diffstat (limited to 'src/util/pass_trigger.c')
| -rw-r--r-- | src/util/pass_trigger.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/src/util/pass_trigger.c b/src/util/pass_trigger.c new file mode 100644 index 0000000..d7d16f2 --- /dev/null +++ b/src/util/pass_trigger.c @@ -0,0 +1,151 @@ +/*++ +/* NAME +/* pass_trigger 3 +/* SUMMARY +/* trigger file descriptor listener +/* SYNOPSIS +/* #include <trigger.h> +/* +/* int pass_trigger(service, buf, len, timeout) +/* const char *service; +/* const char *buf; +/* ssize_t len; +/* int timeout; +/* DESCRIPTION +/* pass_trigger() connects to the named local server by sending +/* a file descriptor to it and writing the named buffer. +/* +/* The connection is closed by a background thread. Some kernels +/* cannot handle client-side disconnect before the server has +/* received the message. +/* +/* Arguments: +/* .IP service +/* Name of the communication endpoint. +/* .IP buf +/* Address of data to be written. +/* .IP len +/* Amount of data to be written. +/* .IP timeout +/* Deadline in seconds. Specify a value <= 0 to disable +/* the time limit. +/* DIAGNOSTICS +/* The result is zero in case of success, -1 in case of problems. +/* SEE ALSO +/* unix_connect(3), local client +/* stream_connect(3), streams-based client +/* 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 <unistd.h> +#include <string.h> + +/* Utility library. */ + +#include <msg.h> +#include <connect.h> +#include <iostuff.h> +#include <mymalloc.h> +#include <events.h> +#include <trigger.h> + +struct pass_trigger { + int connect_fd; + char *service; + int pass_fd[2]; +}; + +/* pass_trigger_event - disconnect from peer */ + +static void pass_trigger_event(int event, void *context) +{ + struct pass_trigger *pp = (struct pass_trigger *) context; + static const char *myname = "pass_trigger_event"; + + /* + * Disconnect. + */ + if (event == EVENT_TIME) + msg_warn("%s: read timeout for service %s", myname, pp->service); + event_disable_readwrite(pp->connect_fd); + event_cancel_timer(pass_trigger_event, context); + /* Don't combine multiple close() calls into one boolean expression. */ + if (close(pp->connect_fd) < 0) + msg_warn("%s: close %s: %m", myname, pp->service); + if (close(pp->pass_fd[0]) < 0) + msg_warn("%s: close pipe: %m", myname); + if (close(pp->pass_fd[1]) < 0) + msg_warn("%s: close pipe: %m", myname); + myfree(pp->service); + myfree((void *) pp); +} + +/* pass_trigger - wakeup local server */ + +int pass_trigger(const char *service, const char *buf, ssize_t len, int timeout) +{ + const char *myname = "pass_trigger"; + int pass_fd[2]; + struct pass_trigger *pp; + int connect_fd; + + if (msg_verbose > 1) + msg_info("%s: service %s", myname, service); + + /* + * Connect... + */ + if ((connect_fd = LOCAL_CONNECT(service, BLOCKING, timeout)) < 0) { + if (msg_verbose) + msg_warn("%s: connect to %s: %m", myname, service); + return (-1); + } + close_on_exec(connect_fd, CLOSE_ON_EXEC); + + /* + * Create a pipe, and send one pipe end to the server. + */ + if (pipe(pass_fd) < 0) + msg_fatal("%s: pipe: %m", myname); + close_on_exec(pass_fd[0], CLOSE_ON_EXEC); + close_on_exec(pass_fd[1], CLOSE_ON_EXEC); + if (LOCAL_SEND_FD(connect_fd, pass_fd[0]) < 0) + msg_fatal("%s: send file descriptor: %m", myname); + + /* + * Stash away context. + */ + pp = (struct pass_trigger *) mymalloc(sizeof(*pp)); + pp->connect_fd = connect_fd; + pp->service = mystrdup(service); + pp->pass_fd[0] = pass_fd[0]; + pp->pass_fd[1] = pass_fd[1]; + + /* + * Write the request... + */ + if (write_buf(pass_fd[1], buf, len, timeout) < 0 + || write_buf(pass_fd[1], "", 1, timeout) < 0) + if (msg_verbose) + msg_warn("%s: write to %s: %m", myname, service); + + /* + * Wakeup when the peer disconnects, or when we lose patience. + */ + if (timeout > 0) + event_request_timer(pass_trigger_event, (void *) pp, timeout + 100); + event_enable_read(connect_fd, pass_trigger_event, (void *) pp); + return (0); +} |