diff options
Diffstat (limited to 'src/protocol/reqrep0/rep.c')
| -rw-r--r-- | src/protocol/reqrep0/rep.c | 515 |
1 files changed, 515 insertions, 0 deletions
diff --git a/src/protocol/reqrep0/rep.c b/src/protocol/reqrep0/rep.c new file mode 100644 index 00000000..ee8e4277 --- /dev/null +++ b/src/protocol/reqrep0/rep.c @@ -0,0 +1,515 @@ +// +// Copyright 2017 Garrett D'Amore <garrett@damore.org> +// Copyright 2017 Capitar IT Group BV <info@capitar.com> +// +// This software is supplied under the terms of the MIT License, a +// copy of which should be located in the distribution where this +// file was obtained (LICENSE.txt). A copy of the license may also be +// found online at https://opensource.org/licenses/MIT. +// + +#include <stdlib.h> +#include <string.h> + +#include "core/nng_impl.h" +#include "protocol/reqrep0/rep.h" + +// Response protocol. The REP protocol is the "reply" side of a +// request-reply pair. This is useful for building RPC servers, for +// example. + +#ifndef NNI_PROTO_REQ_V0 +#define NNI_PROTO_REQ_V0 NNI_PROTO(3, 0) +#endif + +#ifndef NNI_PROTO_REP_V0 +#define NNI_PROTO_REP_V0 NNI_PROTO(3, 1) +#endif + +typedef struct rep0_pipe rep0_pipe; +typedef struct rep0_sock rep0_sock; + +static void rep0_sock_getq_cb(void *); +static void rep0_pipe_getq_cb(void *); +static void rep0_pipe_putq_cb(void *); +static void rep0_pipe_send_cb(void *); +static void rep0_pipe_recv_cb(void *); +static void rep0_pipe_fini(void *); + +// rep0_sock is our per-socket protocol private structure. +struct rep0_sock { + nni_msgq * uwq; + nni_msgq * urq; + nni_mtx lk; + int raw; + int ttl; + nni_idhash *pipes; + char * btrace; + size_t btrace_len; + nni_aio * aio_getq; +}; + +// rep0_pipe is our per-pipe protocol private structure. +struct rep0_pipe { + nni_pipe * pipe; + rep0_sock *rep; + nni_msgq * sendq; + nni_aio * aio_getq; + nni_aio * aio_send; + nni_aio * aio_recv; + nni_aio * aio_putq; +}; + +static void +rep0_sock_fini(void *arg) +{ + rep0_sock *s = arg; + + nni_aio_stop(s->aio_getq); + nni_aio_fini(s->aio_getq); + nni_idhash_fini(s->pipes); + if (s->btrace != NULL) { + nni_free(s->btrace, s->btrace_len); + } + nni_mtx_fini(&s->lk); + NNI_FREE_STRUCT(s); +} + +static int +rep0_sock_init(void **sp, nni_sock *sock) +{ + rep0_sock *s; + int rv; + + if ((s = NNI_ALLOC_STRUCT(s)) == NULL) { + return (NNG_ENOMEM); + } + nni_mtx_init(&s->lk); + if (((rv = nni_idhash_init(&s->pipes)) != 0) || + ((rv = nni_aio_init(&s->aio_getq, rep0_sock_getq_cb, s)) != 0)) { + rep0_sock_fini(s); + return (rv); + } + + s->ttl = 8; // Per RFC + s->raw = 0; + s->btrace = NULL; + s->btrace_len = 0; + s->uwq = nni_sock_sendq(sock); + s->urq = nni_sock_recvq(sock); + + *sp = s; + + return (0); +} + +static void +rep0_sock_open(void *arg) +{ + rep0_sock *s = arg; + + nni_msgq_aio_get(s->uwq, s->aio_getq); +} + +static void +rep0_sock_close(void *arg) +{ + rep0_sock *s = arg; + + nni_aio_cancel(s->aio_getq, NNG_ECLOSED); +} + +static void +rep0_pipe_fini(void *arg) +{ + rep0_pipe *p = arg; + + nni_aio_fini(p->aio_getq); + nni_aio_fini(p->aio_send); + nni_aio_fini(p->aio_recv); + nni_aio_fini(p->aio_putq); + nni_msgq_fini(p->sendq); + NNI_FREE_STRUCT(p); +} + +static int +rep0_pipe_init(void **pp, nni_pipe *pipe, void *s) +{ + rep0_pipe *p; + int rv; + + if ((p = NNI_ALLOC_STRUCT(p)) == NULL) { + return (NNG_ENOMEM); + } + if (((rv = nni_msgq_init(&p->sendq, 2)) != 0) || + ((rv = nni_aio_init(&p->aio_getq, rep0_pipe_getq_cb, p)) != 0) || + ((rv = nni_aio_init(&p->aio_send, rep0_pipe_send_cb, p)) != 0) || + ((rv = nni_aio_init(&p->aio_recv, rep0_pipe_recv_cb, p)) != 0) || + ((rv = nni_aio_init(&p->aio_putq, rep0_pipe_putq_cb, p)) != 0)) { + rep0_pipe_fini(p); + return (rv); + } + + p->pipe = pipe; + p->rep = s; + *pp = p; + return (0); +} + +static int +rep0_pipe_start(void *arg) +{ + rep0_pipe *p = arg; + rep0_sock *s = p->rep; + int rv; + + if ((rv = nni_idhash_insert(s->pipes, nni_pipe_id(p->pipe), p)) != 0) { + return (rv); + } + + nni_msgq_aio_get(p->sendq, p->aio_getq); + nni_pipe_recv(p->pipe, p->aio_recv); + return (0); +} + +static void +rep0_pipe_stop(void *arg) +{ + rep0_pipe *p = arg; + rep0_sock *s = p->rep; + + nni_msgq_close(p->sendq); + nni_aio_stop(p->aio_getq); + nni_aio_stop(p->aio_send); + nni_aio_stop(p->aio_recv); + nni_aio_stop(p->aio_putq); + + nni_idhash_remove(s->pipes, nni_pipe_id(p->pipe)); +} + +static void +rep0_sock_getq_cb(void *arg) +{ + rep0_sock *s = arg; + nni_msgq * uwq = s->uwq; + nni_msg * msg; + uint32_t id; + rep0_pipe *p; + int rv; + + // This watches for messages from the upper write queue, + // extracts the destination pipe, and forwards it to the appropriate + // destination pipe via a separate queue. This prevents a single bad + // or slow pipe from gumming up the works for the entire socket. + + if (nni_aio_result(s->aio_getq) != 0) { + // Closed socket? + return; + } + + msg = nni_aio_get_msg(s->aio_getq); + nni_aio_set_msg(s->aio_getq, NULL); + + // We yank the outgoing pipe id from the header + if (nni_msg_header_len(msg) < 4) { + nni_msg_free(msg); + + // Look for another message on the upper write queue. + nni_msgq_aio_get(uwq, s->aio_getq); + return; + } + + id = nni_msg_header_trim_u32(msg); + + // Look for the pipe, and attempt to put the message there + // (nonblocking) if we can. If we can't for any reason, then we + // free the message. + // XXX: LOCKING?!?! + if ((rv = nni_idhash_find(s->pipes, id, (void **) &p)) == 0) { + rv = nni_msgq_tryput(p->sendq, msg); + } + if (rv != 0) { + nni_msg_free(msg); + } + + // Now look for another message on the upper write queue. + nni_msgq_aio_get(uwq, s->aio_getq); +} + +static void +rep0_pipe_getq_cb(void *arg) +{ + rep0_pipe *p = arg; + + if (nni_aio_result(p->aio_getq) != 0) { + nni_pipe_stop(p->pipe); + return; + } + + nni_aio_set_msg(p->aio_send, nni_aio_get_msg(p->aio_getq)); + nni_aio_set_msg(p->aio_getq, NULL); + + nni_pipe_send(p->pipe, p->aio_send); +} + +static void +rep0_pipe_send_cb(void *arg) +{ + rep0_pipe *p = arg; + + if (nni_aio_result(p->aio_send) != 0) { + nni_msg_free(nni_aio_get_msg(p->aio_send)); + nni_aio_set_msg(p->aio_send, NULL); + nni_pipe_stop(p->pipe); + return; + } + + nni_msgq_aio_get(p->sendq, p->aio_getq); +} + +static void +rep0_pipe_recv_cb(void *arg) +{ + rep0_pipe *p = arg; + rep0_sock *s = p->rep; + nni_msg * msg; + int rv; + uint8_t * body; + int hops; + + if (nni_aio_result(p->aio_recv) != 0) { + nni_pipe_stop(p->pipe); + return; + } + + msg = nni_aio_get_msg(p->aio_recv); + nni_aio_set_msg(p->aio_recv, NULL); + + nni_msg_set_pipe(msg, nni_pipe_id(p->pipe)); + + // Store the pipe id in the header, first thing. + rv = nni_msg_header_append_u32(msg, nni_pipe_id(p->pipe)); + if (rv != 0) { + // Failure here causes us to drop the message. + goto drop; + } + + // Move backtrace from body to header + hops = 1; + for (;;) { + int end = 0; + if (hops >= s->ttl) { + // This isn't malformed, but it has gone through + // too many hops. Do not disconnect, because we + // can legitimately receive messages with too many + // hops from devices, etc. + goto drop; + } + if (nni_msg_len(msg) < 4) { + // Peer is speaking garbage. Kick it. + nni_msg_free(msg); + nni_pipe_stop(p->pipe); + return; + } + body = nni_msg_body(msg); + end = (body[0] & 0x80) ? 1 : 0; + rv = nni_msg_header_append(msg, body, 4); + if (rv != 0) { + // Presumably this is due to out of memory. + // We could just discard and try again, but we + // just toss the connection for now. Given the + // out of memory situation, this is not unreasonable. + goto drop; + } + nni_msg_trim(msg, 4); + if (end) { + break; + } + } + + // Go ahead and send it up. + nni_aio_set_msg(p->aio_putq, msg); + nni_msgq_aio_put(s->urq, p->aio_putq); + return; + +drop: + nni_msg_free(msg); + nni_pipe_recv(p->pipe, p->aio_recv); +} + +static void +rep0_pipe_putq_cb(void *arg) +{ + rep0_pipe *p = arg; + + if (nni_aio_result(p->aio_putq) != 0) { + nni_msg_free(nni_aio_get_msg(p->aio_putq)); + nni_aio_set_msg(p->aio_putq, NULL); + nni_pipe_stop(p->pipe); + return; + } + + nni_pipe_recv(p->pipe, p->aio_recv); +} + +static int +rep0_sock_setopt_raw(void *arg, const void *buf, size_t sz) +{ + rep0_sock *s = arg; + int rv; + + nni_mtx_lock(&s->lk); + rv = nni_setopt_int(&s->raw, buf, sz, 0, 1); + nni_mtx_unlock(&s->lk); + return (rv); +} + +static int +rep0_sock_getopt_raw(void *arg, void *buf, size_t *szp) +{ + rep0_sock *s = arg; + return (nni_getopt_int(s->raw, buf, szp)); +} + +static int +rep0_sock_setopt_maxttl(void *arg, const void *buf, size_t sz) +{ + rep0_sock *s = arg; + return (nni_setopt_int(&s->ttl, buf, sz, 1, 255)); +} + +static int +rep0_sock_getopt_maxttl(void *arg, void *buf, size_t *szp) +{ + rep0_sock *s = arg; + return (nni_getopt_int(s->ttl, buf, szp)); +} + +static nni_msg * +rep0_sock_filter(void *arg, nni_msg *msg) +{ + rep0_sock *s = arg; + char * header; + size_t len; + + nni_mtx_lock(&s->lk); + if (s->raw) { + nni_mtx_unlock(&s->lk); + return (msg); + } + + len = nni_msg_header_len(msg); + header = nni_msg_header(msg); + if (s->btrace != NULL) { + nni_free(s->btrace, s->btrace_len); + s->btrace = NULL; + s->btrace_len = 0; + } + if ((s->btrace = nni_alloc(len)) == NULL) { + nni_msg_free(msg); + return (NULL); + } + s->btrace_len = len; + memcpy(s->btrace, header, len); + nni_msg_header_clear(msg); + nni_mtx_unlock(&s->lk); + return (msg); +} + +static void +rep0_sock_send(void *arg, nni_aio *aio) +{ + rep0_sock *s = arg; + int rv; + nni_msg * msg; + + nni_mtx_lock(&s->lk); + if (s->raw) { + // Pass thru + nni_mtx_unlock(&s->lk); + nni_msgq_aio_put(s->uwq, aio); + return; + } + if (s->btrace == NULL) { + nni_mtx_unlock(&s->lk); + nni_aio_finish_error(aio, NNG_ESTATE); + return; + } + + msg = nni_aio_get_msg(aio); + + // drop anything else in the header... (it should already be + // empty, but there can be stale backtrace info there.) + nni_msg_header_clear(msg); + + if ((rv = nni_msg_header_append(msg, s->btrace, s->btrace_len)) != 0) { + nni_mtx_unlock(&s->lk); + nni_aio_finish_error(aio, rv); + return; + } + + nni_free(s->btrace, s->btrace_len); + s->btrace = NULL; + s->btrace_len = 0; + + nni_mtx_unlock(&s->lk); + nni_msgq_aio_put(s->uwq, aio); +} + +static void +rep0_sock_recv(void *arg, nni_aio *aio) +{ + rep0_sock *s = arg; + + nni_msgq_aio_get(s->urq, aio); +} + +// This is the global protocol structure -- our linkage to the core. +// This should be the only global non-static symbol in this file. +static nni_proto_pipe_ops rep0_pipe_ops = { + .pipe_init = rep0_pipe_init, + .pipe_fini = rep0_pipe_fini, + .pipe_start = rep0_pipe_start, + .pipe_stop = rep0_pipe_stop, +}; + +static nni_proto_sock_option rep0_sock_options[] = { + { + .pso_name = NNG_OPT_RAW, + .pso_getopt = rep0_sock_getopt_raw, + .pso_setopt = rep0_sock_setopt_raw, + }, + { + .pso_name = NNG_OPT_MAXTTL, + .pso_getopt = rep0_sock_getopt_maxttl, + .pso_setopt = rep0_sock_setopt_maxttl, + }, + // terminate list + { NULL, NULL, NULL }, +}; + +static nni_proto_sock_ops rep0_sock_ops = { + .sock_init = rep0_sock_init, + .sock_fini = rep0_sock_fini, + .sock_open = rep0_sock_open, + .sock_close = rep0_sock_close, + .sock_options = rep0_sock_options, + .sock_filter = rep0_sock_filter, + .sock_send = rep0_sock_send, + .sock_recv = rep0_sock_recv, +}; + +static nni_proto rep0_proto = { + .proto_version = NNI_PROTOCOL_VERSION, + .proto_self = { NNI_PROTO_REP_V0, "rep" }, + .proto_peer = { NNI_PROTO_REQ_V0, "req" }, + .proto_flags = NNI_PROTO_FLAG_SNDRCV, + .proto_sock_ops = &rep0_sock_ops, + .proto_pipe_ops = &rep0_pipe_ops, +}; + +int +nng_rep0_open(nng_socket *sidp) +{ + return (nni_proto_open(sidp, &rep0_proto)); +} |