diff options
author | Ralph Boehme <slow@samba.org> | 2015-10-18 22:21:10 +0200 |
---|---|---|
committer | Jeremy Allison <jra@samba.org> | 2015-10-20 20:22:22 +0200 |
commit | 05d4dbda8357712cb81008e0d611fdb0e7239587 (patch) | |
tree | 04f0b8cc85271f6cac4376b238c715445f3d0db4 /lib/async_req | |
parent | aa96c75346a9bad60471a206d65c7b7049b9ca83 (diff) | |
download | samba-05d4dbda8357712cb81008e0d611fdb0e7239587.tar.gz |
async_req: fix non-blocking connect()
According to Stevens UNIX Network Programming and various other sources,
the correct handling for non-blocking connect() is:
- when the initial connect() return -1/EINPROGRESS polling the socket
for *writeability*
- in the poll handler call getsocktopt() with SO_ERROR to get the
finished connect() return value
Simply calling connect() a second time without error checking is
probably wrong and not portable. For a successfull connect() Linux
returns 0, but Solaris will return EISCONN:
24254: 0.0336 0.0002 connect(4, 0xFEFFECAC, 16, SOV_DEFAULT) Err#150 EINPROGRESS
24254: AF_INET name = 10.10.10.143 port = 1024
24254: 0.0349 0.0001 port_associate(3, 4, 0x00000004, 0x0000001D,0x080648A8) = 0
24254: 0.0495 0.0146 port_getn(3, 0xFEFFEB50, 1, 1, 0xFEFFEB60) = 1 [0]
24254: 0.0497 0.0002 connect(4, 0x080646E4, 16, SOV_DEFAULT) Err#133 EISCONN
24254: AF_INET name = 10.10.10.143 port = 1024
Bug: https://bugzilla.samba.org/show_bug.cgi?id=11564
Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Diffstat (limited to 'lib/async_req')
-rw-r--r-- | lib/async_req/async_sock.c | 56 |
1 files changed, 27 insertions, 29 deletions
diff --git a/lib/async_req/async_sock.c b/lib/async_req/async_sock.c index bc3780c9199..c0ad8f303b8 100644 --- a/lib/async_req/async_sock.c +++ b/lib/async_req/async_sock.c @@ -127,24 +127,17 @@ struct tevent_req *async_connect_send( return tevent_req_post(req, ev); } - /** - * A number of error messages show that something good is progressing - * and that we have to wait for readability. - * - * If none of them are present, bail out. + /* + * The only errno indicating that the connect is still in + * flight is EINPROGRESS, everything else is an error */ - if (!(errno == EINPROGRESS || errno == EALREADY || -#ifdef EISCONN - errno == EISCONN || -#endif - errno == EAGAIN || errno == EINTR)) { + if (errno != EINPROGRESS) { tevent_req_error(req, errno); return tevent_req_post(req, ev); } - state->fde = tevent_add_fd(ev, state, fd, - TEVENT_FD_READ | TEVENT_FD_WRITE, + state->fde = tevent_add_fd(ev, state, fd, TEVENT_FD_WRITE, async_connect_connected, req); if (state->fde == NULL) { tevent_req_error(req, ENOMEM); @@ -189,27 +182,32 @@ static void async_connect_connected(struct tevent_context *ev, struct async_connect_state *state = tevent_req_data(req, struct async_connect_state); int ret; - - if (state->before_connect != NULL) { - state->before_connect(state->private_data); - } - - ret = connect(state->fd, (struct sockaddr *)(void *)&state->address, - state->address_len); - - if (state->after_connect != NULL) { - state->after_connect(state->private_data); - } - - if (ret == 0) { - tevent_req_done(req); + int socket_error = 0; + socklen_t slen = sizeof(socket_error); + + ret = getsockopt(state->fd, SOL_SOCKET, SO_ERROR, + &socket_error, &slen); + + if (ret != 0) { + /* + * According to Stevens this is the Solaris behaviour + * in case the connection encountered an error: + * getsockopt() fails, error is in errno + */ + tevent_req_error(req, errno); return; } - if (errno == EINPROGRESS) { - /* Try again later, leave the fde around */ + + if (socket_error != 0) { + /* + * Berkeley derived implementations (including) Linux + * return the pending error via socket_error. + */ + tevent_req_error(req, socket_error); return; } - tevent_req_error(req, errno); + + tevent_req_done(req); return; } |