laforge has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmo-netif/+/36244?usp=email )

Change subject: osmo_stream_cli_send(): Drop data if client is not connected [yet] ......................................................................

osmo_stream_cli_send(): Drop data if client is not connected [yet]

The behaviour is undefined on what should happen if a stream client user is trying to write data before the client socket is connected. In osmo_io mode we would actually crash due to a NULL-pointer dereference.

Let's discard any sent data in this situation and print a related error log message.

This problem actually shows up with osmo-bsc Change-Id Icce412e6ee69366c7b131c9bc1d51e8d44204917 where we convert CBSP over to osmo_io - here in situations where a CBSP client (using stream_cli) was previously connected but has lost its connection.

Change-Id: I18d2e8e850c23a32f5983a715fa8a18747b296cd --- M src/stream_cli.c 1 file changed, 28 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/libosmo-netif refs/changes/44/36244/1

diff --git a/src/stream_cli.c b/src/stream_cli.c index 8312faf..1a100ca 100644 --- a/src/stream_cli.c +++ b/src/stream_cli.c @@ -1003,12 +1003,20 @@ OSMO_ASSERT(cli); OSMO_ASSERT(msg);

+ if (!osmo_stream_cli_is_connected(cli)) { + LOGSCLI(cli, LOGL_ERROR, "send: not connected, dropping data!\n"); + msgb_free(msg); + return; + } + switch (cli->mode) { case OSMO_STREAM_MODE_OSMO_FD: msgb_enqueue(&cli->tx_queue, msg); osmo_fd_write_enable(&cli->ofd); break; case OSMO_STREAM_MODE_OSMO_IO: + /* whenever osmo_stream_cli_is_connected() [see above check], we should have an iofd /* + OSMO_ASSERT(cli->iofd); if (cli->proto == IPPROTO_SCTP) rc = stream_iofd_sctp_send_msgb(cli->iofd, msg, MSG_NOSIGNAL); else