diff options
Diffstat (limited to 'udp.c')
| -rw-r--r-- | udp.c | 46 |
1 files changed, 24 insertions, 22 deletions
@@ -39,27 +39,30 @@ * could receive packets from multiple flows, so we use a hash table match to * find the specific flow for a datagram. * - * When a UDP flow is initiated from a listening socket we take a duplicate of - * the socket and store it in uflow->s[INISIDE]. This will last for the - * lifetime of the flow, even if the original listening socket is closed due to - * port auto-probing. The duplicate is used to deliver replies back to the - * originating side. - * - * Reply sockets - * ============= + * Flow sockets + * ============ * - * When a UDP flow targets a socket, we create a "reply" socket in + * When a UDP flow targets a socket, we create a "flow" socket in * uflow->s[TGTSIDE] both to deliver datagrams to the target side and receive * replies on the target side. This socket is both bound and connected and has - * EPOLL_TYPE_UDP_REPLY. The connect() means it will only receive datagrams + * EPOLL_TYPE_UDP. The connect() means it will only receive datagrams * associated with this flow, so the epoll reference directly points to the flow * and we don't need a hash lookup. * - * NOTE: it's possible that the reply socket could have a bound address - * overlapping with an unrelated listening socket. We assume datagrams for the - * flow will come to the reply socket in preference to a listening socket. The - * sample program doc/platform-requirements/reuseaddr-priority.c documents and - * tests that assumption. + * When a flow is initiated from a listening socket, we create a "flow" socket + * with the same bound address as the listening socket, but also connect()ed to + * the flow's peer. This is stored in uflow->s[INISIDE] and will last for the + * lifetime of the flow, even if the original listening socket is closed due to + * port auto-probing. The duplicate is used to deliver replies back to the + * originating side. + * + * NOTE: A flow socket can have a bound address overlapping with a listening + * socket. That will happen naturally for flows initiated from a socket, but is + * also possible (though unlikely) for tap initiated flows, depending on the + * source port. We assume datagrams for the flow will come to a connect()ed + * socket in preference to a listening socket. The sample program + * doc/platform-requirements/reuseaddr-priority.c documents and tests that + * assumption. * * "Spliced" flows * =============== @@ -71,8 +74,7 @@ * actually used; it doesn't make sense for datagrams and instead a pair of * recvmmsg() and sendmmsg() is used to forward the datagrams. * - * Note that a spliced flow will have *both* a duplicated listening socket and a - * reply socket (see above). + * Note that a spliced flow will have two flow sockets (see above). */ #include <sched.h> @@ -557,7 +559,7 @@ static int udp_sock_recverr(const struct ctx *c, union epoll_ref ref) } eh = (const struct errhdr *)CMSG_DATA(hdr); - if (ref.type == EPOLL_TYPE_UDP_REPLY) { + if (ref.type == EPOLL_TYPE_UDP) { flow_sidx_t sidx = flow_sidx_opposite(ref.flowside); const struct flowside *toside = flowside_at_sidx(sidx); size_t dlen = rc; @@ -792,14 +794,14 @@ static bool udp_buf_reply_sock_data(const struct ctx *c, } /** - * udp_reply_sock_handler() - Handle new data from flow specific socket + * udp_sock_handler() - Handle new data from flow specific socket * @c: Execution context * @ref: epoll reference * @events: epoll events bitmap * @now: Current timestamp */ -void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref, - uint32_t events, const struct timespec *now) +void udp_sock_handler(const struct ctx *c, union epoll_ref ref, + uint32_t events, const struct timespec *now) { struct udp_flow *uflow = udp_at_sidx(ref.flowside); @@ -807,7 +809,7 @@ void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref, if (events & EPOLLERR) { if (udp_sock_errs(c, ref) < 0) { - flow_err(uflow, "Unrecoverable error on reply socket"); + flow_err(uflow, "Unrecoverable error on flow socket"); goto fail; } } |