Commit 2989ad90 authored by Paul Eggert's avatar Paul Eggert

Try other addresses when connecting to multihomed

Problem reported by Juliusz Chroboczek (Bug#17976)
and by Artur Malabarba (Bug#23620).
Patch from a suggestion by Andreas Schwab in:
http://bugs.gnu.org/17976#39
This patch is for non-MS-Windows platforms.
I don't know the situation on MS-Windows.
* src/process.c (connecting_status):
New function, for (connect . ADDRINFOS).
(connect_network_socket, check_for_dns, wait_for_socket_fds)
(wait_while_connecting, wait_reading_process_output, status_notify):
Use it.
(decode_status, Fmake_network_process):
Support (connect . ADDRINFOS) status.
(connect_network_socket) [!WINDOWSNT]:
If the connection failed and there are other addresses to try, do not
signal an error; instead, loop around to try the next address.
(wait_reading_process_output): Advance to the next address
if there are multiple addresses and the first remaining address
failed.
* src/process.h (struct Lisp_Process.status): Adjust comment
to describe (connect . ADDRINFOS).
parent d267aea2
......@@ -533,6 +533,14 @@ status_convert (int w)
return Qrun;
}
/* True if STATUS is that of a process attempting connection. */
static bool
connecting_status (Lisp_Object status)
{
return CONSP (status) && EQ (XCAR (status), Qconnect);
}
/* Given a status-list, extract the three pieces of information
and store them individually through the three pointers. */
......@@ -542,6 +550,9 @@ decode_status (Lisp_Object l, Lisp_Object *symbol, Lisp_Object *code,
{
Lisp_Object tem;
if (connecting_status (l))
l = XCAR (l);
if (SYMBOLP (l))
{
*symbol = l;
......@@ -3288,9 +3299,10 @@ connect_network_socket (Lisp_Object proc, Lisp_Object addrinfos,
eassert (FD_ISSET (s, &fdset));
if (getsockopt (s, SOL_SOCKET, SO_ERROR, &xerrno, &len) < 0)
report_file_error ("Failed getsockopt", Qnil);
if (xerrno)
if (xerrno == 0)
break;
if (NILP (addrinfos))
report_file_errno ("Failed connect", Qnil, xerrno);
break;
}
#endif /* !WINDOWSNT */
......@@ -3399,7 +3411,9 @@ connect_network_socket (Lisp_Object proc, Lisp_Object addrinfos,
/* We may get here if connect did succeed immediately. However,
in that case, we still need to signal this like a non-blocking
connection. */
pset_status (p, Qconnect);
if (! (connecting_status (p->status)
&& EQ (XCDR (p->status), addrinfos)))
pset_status (p, Fcons (Qconnect, addrinfos));
if (!FD_ISSET (inch, &connect_wait_mask))
{
FD_SET (inch, &connect_wait_mask);
......@@ -3960,7 +3974,7 @@ usage: (make-network-process &rest ARGS) */)
if (!p->is_server && NILP (addrinfos))
{
p->dns_request = dns_request;
p->status = Qconnect;
p->status = list1 (Qconnect);
return proc;
}
#endif
......@@ -4673,7 +4687,7 @@ check_for_dns (Lisp_Object proc)
addrinfos = Fnreverse (addrinfos);
}
/* The DNS lookup failed. */
else if (EQ (p->status, Qconnect))
else if (connecting_status (p->status))
{
deactivate_process (proc);
pset_status (p, (list2
......@@ -4686,7 +4700,7 @@ check_for_dns (Lisp_Object proc)
free_dns_request (proc);
/* This process should not already be connected (or killed). */
if (!EQ (p->status, Qconnect))
if (! connecting_status (p->status))
return Qnil;
return addrinfos;
......@@ -4698,7 +4712,7 @@ static void
wait_for_socket_fds (Lisp_Object process, char const *name)
{
while (XPROCESS (process)->infd < 0
&& EQ (XPROCESS (process)->status, Qconnect))
&& connecting_status (XPROCESS (process)->status))
{
add_to_log ("Waiting for socket from %s...", build_string (name));
wait_reading_process_output (0, 20 * 1000 * 1000, 0, 0, Qnil, NULL, 0);
......@@ -4708,7 +4722,7 @@ wait_for_socket_fds (Lisp_Object process, char const *name)
static void
wait_while_connecting (Lisp_Object process)
{
while (EQ (XPROCESS (process)->status, Qconnect))
while (connecting_status (XPROCESS (process)->status))
{
add_to_log ("Waiting for connection...");
wait_reading_process_output (0, 20 * 1000 * 1000, 0, 0, Qnil, NULL, 0);
......@@ -5010,7 +5024,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
update_status (wait_proc);
if (wait_proc
&& ! EQ (wait_proc->status, Qrun)
&& ! EQ (wait_proc->status, Qconnect))
&& ! connecting_status (wait_proc->status))
{
bool read_some_bytes = false;
......@@ -5520,9 +5534,18 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
#endif
if (xerrno)
{
p->tick = ++process_tick;
pset_status (p, list2 (Qfailed, make_number (xerrno)));
Lisp_Object addrinfos
= connecting_status (p->status) ? XCDR (p->status) : Qnil;
if (!NILP (addrinfos))
XSETCDR (p->status, XCDR (addrinfos));
else
{
p->tick = ++process_tick;
pset_status (p, list2 (Qfailed, make_number (xerrno)));
}
deactivate_process (proc);
if (!NILP (addrinfos))
connect_network_socket (proc, addrinfos, Qnil);
}
else
{
......@@ -6999,7 +7022,7 @@ status_notify (struct Lisp_Process *deleting_process,
/* If process is still active, read any output that remains. */
while (! EQ (p->filter, Qt)
&& ! EQ (p->status, Qconnect)
&& ! connecting_status (p->status)
&& ! EQ (p->status, Qlisten)
/* Network or serial process not stopped: */
&& ! EQ (p->command, Qt)
......
......@@ -83,7 +83,9 @@ struct Lisp_Process
Lisp_Object mark;
/* Symbol indicating status of process.
This may be a symbol: run, open, closed, listen, connect, or failed.
This may be a symbol: run, open, closed, listen, or failed.
Or it may be a pair (connect . ADDRINFOS) where ADDRINFOS is
a list of remaining (PROTOCOL . ADDRINFO) pairs to try.
Or it may be (failed ERR) where ERR is an integer, string or symbol.
Or it may be a list, whose car is stop, exit or signal
and whose cdr is a pair (EXIT_CODE . COREDUMP_FLAG)
......
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