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-rw-r--r--src/sp/protocol/reqrep0/rep.c705
1 files changed, 705 insertions, 0 deletions
diff --git a/src/sp/protocol/reqrep0/rep.c b/src/sp/protocol/reqrep0/rep.c
new file mode 100644
index 00000000..aa32d249
--- /dev/null
+++ b/src/sp/protocol/reqrep0/rep.c
@@ -0,0 +1,705 @@
+//
+// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 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 <string.h>
+
+#include "core/nng_impl.h"
+#include "nng/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.
+
+typedef struct rep0_pipe rep0_pipe;
+typedef struct rep0_sock rep0_sock;
+typedef struct rep0_ctx rep0_ctx;
+
+static void rep0_pipe_send_cb(void *);
+static void rep0_pipe_recv_cb(void *);
+static void rep0_pipe_fini(void *);
+
+struct rep0_ctx {
+ rep0_sock * sock;
+ uint32_t pipe_id;
+ rep0_pipe * spipe; // send pipe
+ nni_aio * saio; // send aio
+ nni_aio * raio; // recv aio
+ nni_list_node sqnode;
+ nni_list_node rqnode;
+ size_t btrace_len;
+ uint32_t btrace[NNI_MAX_MAX_TTL + 1];
+};
+
+// rep0_sock is our per-socket protocol private structure.
+struct rep0_sock {
+ nni_mtx lk;
+ nni_atomic_int ttl;
+ nni_id_map pipes;
+ nni_list recvpipes; // list of pipes with data to receive
+ nni_list recvq;
+ rep0_ctx ctx;
+ nni_pollable readable;
+ nni_pollable writable;
+};
+
+// rep0_pipe is our per-pipe protocol private structure.
+struct rep0_pipe {
+ nni_pipe * pipe;
+ rep0_sock * rep;
+ uint32_t id;
+ nni_aio aio_send;
+ nni_aio aio_recv;
+ nni_list_node rnode; // receivable list linkage
+ nni_list sendq; // contexts waiting to send
+ bool busy;
+ bool closed;
+};
+
+static void
+rep0_ctx_close(void *arg)
+{
+ rep0_ctx * ctx = arg;
+ rep0_sock *s = ctx->sock;
+ nni_aio * aio;
+
+ nni_mtx_lock(&s->lk);
+ if ((aio = ctx->saio) != NULL) {
+ rep0_pipe *pipe = ctx->spipe;
+ ctx->saio = NULL;
+ ctx->spipe = NULL;
+ nni_list_remove(&pipe->sendq, ctx);
+ nni_aio_finish_error(aio, NNG_ECLOSED);
+ }
+ if ((aio = ctx->raio) != NULL) {
+ nni_list_remove(&s->recvq, ctx);
+ ctx->raio = NULL;
+ nni_aio_finish_error(aio, NNG_ECLOSED);
+ }
+ nni_mtx_unlock(&s->lk);
+}
+
+static void
+rep0_ctx_fini(void *arg)
+{
+ rep0_ctx *ctx = arg;
+
+ rep0_ctx_close(ctx);
+}
+
+static int
+rep0_ctx_init(void *carg, void *sarg)
+{
+ rep0_sock *s = sarg;
+ rep0_ctx * ctx = carg;
+
+ NNI_LIST_NODE_INIT(&ctx->sqnode);
+ NNI_LIST_NODE_INIT(&ctx->rqnode);
+ ctx->btrace_len = 0;
+ ctx->sock = s;
+ ctx->pipe_id = 0;
+
+ return (0);
+}
+
+static void
+rep0_ctx_cancel_send(nni_aio *aio, void *arg, int rv)
+{
+ rep0_ctx * ctx = arg;
+ rep0_sock *s = ctx->sock;
+
+ nni_mtx_lock(&s->lk);
+ if (ctx->saio != aio) {
+ nni_mtx_unlock(&s->lk);
+ return;
+ }
+ nni_list_node_remove(&ctx->sqnode);
+ ctx->saio = NULL;
+ nni_mtx_unlock(&s->lk);
+
+ nni_msg_header_clear(nni_aio_get_msg(aio)); // reset the headers
+ nni_aio_finish_error(aio, rv);
+}
+
+static void
+rep0_ctx_send(void *arg, nni_aio *aio)
+{
+ rep0_ctx * ctx = arg;
+ rep0_sock *s = ctx->sock;
+ rep0_pipe *p;
+ nni_msg * msg;
+ int rv;
+ size_t len;
+ uint32_t p_id; // pipe id
+
+ msg = nni_aio_get_msg(aio);
+ nni_msg_header_clear(msg);
+
+ if (nni_aio_begin(aio) != 0) {
+ return;
+ }
+
+ nni_mtx_lock(&s->lk);
+ len = ctx->btrace_len;
+ p_id = ctx->pipe_id;
+
+ // Assert "completion" of the previous req request. This ensures
+ // exactly one send for one receive ordering.
+ ctx->btrace_len = 0;
+ ctx->pipe_id = 0;
+
+ if (ctx == &s->ctx) {
+ // No matter how this goes, we will no longer be able
+ // to send on the socket (root context). That's because
+ // we will have finished (successfully or otherwise) the
+ // reply for the single request we got.
+ nni_pollable_clear(&s->writable);
+ }
+ if (len == 0) {
+ nni_mtx_unlock(&s->lk);
+ nni_aio_finish_error(aio, NNG_ESTATE);
+ return;
+ }
+ if ((rv = nni_msg_header_append(msg, ctx->btrace, len)) != 0) {
+ nni_mtx_unlock(&s->lk);
+ nni_aio_finish_error(aio, rv);
+ return;
+ }
+ if ((p = nni_id_get(&s->pipes, p_id)) == NULL) {
+ // Pipe is gone. Make this look like a good send to avoid
+ // disrupting the state machine. We don't care if the peer
+ // lost interest in our reply.
+ nni_mtx_unlock(&s->lk);
+ nni_aio_set_msg(aio, NULL);
+ nni_aio_finish(aio, 0, nni_msg_len(msg));
+ nni_msg_free(msg);
+ return;
+ }
+ if (!p->busy) {
+ p->busy = true;
+ len = nni_msg_len(msg);
+ nni_aio_set_msg(&p->aio_send, msg);
+ nni_pipe_send(p->pipe, &p->aio_send);
+ nni_mtx_unlock(&s->lk);
+
+ nni_aio_set_msg(aio, NULL);
+ nni_aio_finish(aio, 0, len);
+ return;
+ }
+
+ if ((rv = nni_aio_schedule(aio, rep0_ctx_cancel_send, ctx)) != 0) {
+ nni_mtx_unlock(&s->lk);
+ nni_aio_finish_error(aio, rv);
+ return;
+ }
+
+ ctx->saio = aio;
+ ctx->spipe = p;
+ nni_list_append(&p->sendq, ctx);
+ nni_mtx_unlock(&s->lk);
+}
+
+static void
+rep0_sock_fini(void *arg)
+{
+ rep0_sock *s = arg;
+
+ nni_id_map_fini(&s->pipes);
+ rep0_ctx_fini(&s->ctx);
+ nni_pollable_fini(&s->writable);
+ nni_pollable_fini(&s->readable);
+ nni_mtx_fini(&s->lk);
+}
+
+static int
+rep0_sock_init(void *arg, nni_sock *sock)
+{
+ rep0_sock *s = arg;
+
+ NNI_ARG_UNUSED(sock);
+
+ nni_mtx_init(&s->lk);
+ nni_id_map_init(&s->pipes, 0, 0, false);
+ NNI_LIST_INIT(&s->recvq, rep0_ctx, rqnode);
+ NNI_LIST_INIT(&s->recvpipes, rep0_pipe, rnode);
+ nni_atomic_init(&s->ttl);
+ nni_atomic_set(&s->ttl, 8);
+
+ (void) rep0_ctx_init(&s->ctx, s);
+
+ // We start off without being either readable or writable.
+ // Readability comes when there is something on the socket.
+ nni_pollable_init(&s->writable);
+ nni_pollable_init(&s->readable);
+
+ return (0);
+}
+
+static void
+rep0_sock_open(void *arg)
+{
+ NNI_ARG_UNUSED(arg);
+}
+
+static void
+rep0_sock_close(void *arg)
+{
+ rep0_sock *s = arg;
+
+ rep0_ctx_close(&s->ctx);
+}
+
+static void
+rep0_pipe_stop(void *arg)
+{
+ rep0_pipe *p = arg;
+
+ nni_aio_stop(&p->aio_send);
+ nni_aio_stop(&p->aio_recv);
+}
+
+static void
+rep0_pipe_fini(void *arg)
+{
+ rep0_pipe *p = arg;
+ nng_msg * msg;
+
+ if ((msg = nni_aio_get_msg(&p->aio_recv)) != NULL) {
+ nni_aio_set_msg(&p->aio_recv, NULL);
+ nni_msg_free(msg);
+ }
+
+ nni_aio_fini(&p->aio_send);
+ nni_aio_fini(&p->aio_recv);
+}
+
+static int
+rep0_pipe_init(void *arg, nni_pipe *pipe, void *s)
+{
+ rep0_pipe *p = arg;
+
+ nni_aio_init(&p->aio_send, rep0_pipe_send_cb, p);
+ nni_aio_init(&p->aio_recv, rep0_pipe_recv_cb, p);
+
+ NNI_LIST_INIT(&p->sendq, rep0_ctx, sqnode);
+
+ p->id = nni_pipe_id(pipe);
+ p->pipe = pipe;
+ p->rep = s;
+ return (0);
+}
+
+static int
+rep0_pipe_start(void *arg)
+{
+ rep0_pipe *p = arg;
+ rep0_sock *s = p->rep;
+ int rv;
+
+ if (nni_pipe_peer(p->pipe) != NNG_REP0_PEER) {
+ // Peer protocol mismatch.
+ return (NNG_EPROTO);
+ }
+
+ nni_mtx_lock(&s->lk);
+ rv = nni_id_set(&s->pipes, nni_pipe_id(p->pipe), p);
+ nni_mtx_unlock(&s->lk);
+ if (rv != 0) {
+ return (rv);
+ }
+ // By definition, we have not received a request yet on this pipe,
+ // so it cannot cause us to become writable.
+ nni_pipe_recv(p->pipe, &p->aio_recv);
+ return (0);
+}
+
+static void
+rep0_pipe_close(void *arg)
+{
+ rep0_pipe *p = arg;
+ rep0_sock *s = p->rep;
+ rep0_ctx * ctx;
+
+ nni_aio_close(&p->aio_send);
+ nni_aio_close(&p->aio_recv);
+
+ nni_mtx_lock(&s->lk);
+ p->closed = true;
+ if (nni_list_active(&s->recvpipes, p)) {
+ // We are no longer "receivable".
+ nni_list_remove(&s->recvpipes, p);
+ }
+ while ((ctx = nni_list_first(&p->sendq)) != NULL) {
+ nni_aio *aio;
+ nni_msg *msg;
+ // Pipe was closed. To avoid pushing an error back to the
+ // entire socket, we pretend we completed this successfully.
+ nni_list_remove(&p->sendq, ctx);
+ aio = ctx->saio;
+ ctx->saio = NULL;
+ msg = nni_aio_get_msg(aio);
+ nni_aio_set_msg(aio, NULL);
+ nni_aio_finish(aio, 0, nni_msg_len(msg));
+ nni_msg_free(msg);
+ }
+ if (p->id == s->ctx.pipe_id) {
+ // We "can" send. (Well, not really, but we will happily
+ // accept a message and discard it.)
+ nni_pollable_raise(&s->writable);
+ }
+ nni_id_remove(&s->pipes, nni_pipe_id(p->pipe));
+ nni_mtx_unlock(&s->lk);
+}
+
+static void
+rep0_pipe_send_cb(void *arg)
+{
+ rep0_pipe *p = arg;
+ rep0_sock *s = p->rep;
+ rep0_ctx * ctx;
+ nni_aio * aio;
+ nni_msg * msg;
+ size_t len;
+
+ 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_close(p->pipe);
+ return;
+ }
+ nni_mtx_lock(&s->lk);
+ p->busy = false;
+ if ((ctx = nni_list_first(&p->sendq)) == NULL) {
+ // Nothing else to send.
+ if (p->id == s->ctx.pipe_id) {
+ // Mark us ready for the other side to send!
+ nni_pollable_raise(&s->writable);
+ }
+ nni_mtx_unlock(&s->lk);
+ return;
+ }
+
+ nni_list_remove(&p->sendq, ctx);
+ aio = ctx->saio;
+ ctx->saio = NULL;
+ ctx->spipe = NULL;
+ p->busy = true;
+ msg = nni_aio_get_msg(aio);
+ len = nni_msg_len(msg);
+ nni_aio_set_msg(aio, NULL);
+ nni_aio_set_msg(&p->aio_send, msg);
+ nni_pipe_send(p->pipe, &p->aio_send);
+
+ nni_mtx_unlock(&s->lk);
+
+ nni_aio_finish_sync(aio, 0, len);
+}
+
+static void
+rep0_cancel_recv(nni_aio *aio, void *arg, int rv)
+{
+ rep0_ctx * ctx = arg;
+ rep0_sock *s = ctx->sock;
+
+ nni_mtx_lock(&s->lk);
+ if (ctx->raio == aio) {
+ nni_list_remove(&s->recvq, ctx);
+ ctx->raio = NULL;
+ nni_aio_finish_error(aio, rv);
+ }
+ nni_mtx_unlock(&s->lk);
+}
+
+static void
+rep0_ctx_recv(void *arg, nni_aio *aio)
+{
+ rep0_ctx * ctx = arg;
+ rep0_sock *s = ctx->sock;
+ rep0_pipe *p;
+ size_t len;
+ nni_msg * msg;
+
+ if (nni_aio_begin(aio) != 0) {
+ return;
+ }
+ nni_mtx_lock(&s->lk);
+ if ((p = nni_list_first(&s->recvpipes)) == NULL) {
+ int rv;
+ if ((rv = nni_aio_schedule(aio, rep0_cancel_recv, ctx)) != 0) {
+ nni_mtx_unlock(&s->lk);
+ nni_aio_finish_error(aio, rv);
+ return;
+ }
+ if (ctx->raio != NULL) {
+ // Cannot have a second receive operation pending.
+ // This could be ESTATE, or we could cancel the first
+ // with ECANCELED. We elect the former.
+ nni_mtx_unlock(&s->lk);
+ nni_aio_finish_error(aio, NNG_ESTATE);
+ return;
+ }
+ ctx->raio = aio;
+ nni_list_append(&s->recvq, ctx);
+ nni_mtx_unlock(&s->lk);
+ return;
+ }
+ msg = nni_aio_get_msg(&p->aio_recv);
+ nni_aio_set_msg(&p->aio_recv, NULL);
+ nni_list_remove(&s->recvpipes, p);
+ if (nni_list_empty(&s->recvpipes)) {
+ nni_pollable_clear(&s->readable);
+ }
+ nni_pipe_recv(p->pipe, &p->aio_recv);
+ if ((ctx == &s->ctx) && !p->busy) {
+ nni_pollable_raise(&s->writable);
+ }
+
+ len = nni_msg_header_len(msg);
+ memcpy(ctx->btrace, nni_msg_header(msg), len);
+ ctx->btrace_len = len;
+ ctx->pipe_id = nni_pipe_id(p->pipe);
+ nni_mtx_unlock(&s->lk);
+
+ nni_msg_header_clear(msg);
+ nni_aio_set_msg(aio, msg);
+ nni_aio_finish(aio, 0, nni_msg_len(msg));
+}
+
+static void
+rep0_pipe_recv_cb(void *arg)
+{
+ rep0_pipe *p = arg;
+ rep0_sock *s = p->rep;
+ rep0_ctx * ctx;
+ nni_msg * msg;
+ uint8_t * body;
+ nni_aio * aio;
+ size_t len;
+ int hops;
+ int ttl;
+
+ if (nni_aio_result(&p->aio_recv) != 0) {
+ nni_pipe_close(p->pipe);
+ return;
+ }
+
+ msg = nni_aio_get_msg(&p->aio_recv);
+ ttl = nni_atomic_get(&s->ttl);
+
+ nni_msg_set_pipe(msg, p->id);
+
+ // Move backtrace from body to header
+ hops = 1;
+ for (;;) {
+ bool end;
+
+ if (hops > 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;
+ }
+ hops++;
+ if (nni_msg_len(msg) < 4) {
+ // Peer is speaking garbage. Kick it.
+ nni_msg_free(msg);
+ nni_aio_set_msg(&p->aio_recv, NULL);
+ nni_pipe_close(p->pipe);
+ return;
+ }
+ body = nni_msg_body(msg);
+ end = ((body[0] & 0x80u) != 0);
+ if (nni_msg_header_append(msg, body, 4) != 0) {
+ // Out of memory, so drop it.
+ goto drop;
+ }
+ nni_msg_trim(msg, 4);
+ if (end) {
+ break;
+ }
+ }
+
+ len = nni_msg_header_len(msg);
+
+ nni_mtx_lock(&s->lk);
+
+ if (p->closed) {
+ // If we are closed, then we can't return data.
+ nni_aio_set_msg(&p->aio_recv, NULL);
+ nni_mtx_unlock(&s->lk);
+ nni_msg_free(msg);
+ return;
+ }
+
+ if ((ctx = nni_list_first(&s->recvq)) == NULL) {
+ // No one waiting to receive yet, holding pattern.
+ nni_list_append(&s->recvpipes, p);
+ nni_pollable_raise(&s->readable);
+ nni_mtx_unlock(&s->lk);
+ return;
+ }
+
+ nni_list_remove(&s->recvq, ctx);
+ aio = ctx->raio;
+ ctx->raio = NULL;
+ nni_aio_set_msg(&p->aio_recv, NULL);
+ if ((ctx == &s->ctx) && !p->busy) {
+ nni_pollable_raise(&s->writable);
+ }
+
+ // schedule another receive
+ nni_pipe_recv(p->pipe, &p->aio_recv);
+
+ ctx->btrace_len = len;
+ memcpy(ctx->btrace, nni_msg_header(msg), len);
+ nni_msg_header_clear(msg);
+ ctx->pipe_id = p->id;
+
+ nni_mtx_unlock(&s->lk);
+
+ nni_aio_set_msg(aio, msg);
+ nni_aio_finish_sync(aio, 0, nni_msg_len(msg));
+ return;
+
+drop:
+ nni_msg_free(msg);
+ nni_aio_set_msg(&p->aio_recv, NULL);
+ nni_pipe_recv(p->pipe, &p->aio_recv);
+}
+
+static int
+rep0_sock_set_max_ttl(void *arg, const void *buf, size_t sz, nni_opt_type t)
+{
+ rep0_sock *s = arg;
+ int ttl;
+ int rv;
+
+ if ((rv = nni_copyin_int(&ttl, buf, sz, 1, NNI_MAX_MAX_TTL, t)) == 0) {
+ nni_atomic_set(&s->ttl, ttl);
+ }
+ return (rv);
+}
+
+static int
+rep0_sock_get_max_ttl(void *arg, void *buf, size_t *szp, nni_opt_type t)
+{
+ rep0_sock *s = arg;
+
+ return (nni_copyout_int(nni_atomic_get(&s->ttl), buf, szp, t));
+}
+
+static int
+rep0_sock_get_sendfd(void *arg, void *buf, size_t *szp, nni_opt_type t)
+{
+ rep0_sock *s = arg;
+ int rv;
+ int fd;
+
+ if ((rv = nni_pollable_getfd(&s->writable, &fd)) != 0) {
+ return (rv);
+ }
+ return (nni_copyout_int(fd, buf, szp, t));
+}
+
+static int
+rep0_sock_get_recvfd(void *arg, void *buf, size_t *szp, nni_opt_type t)
+{
+ rep0_sock *s = arg;
+ int rv;
+ int fd;
+
+ if ((rv = nni_pollable_getfd(&s->readable, &fd)) != 0) {
+ return (rv);
+ }
+
+ return (nni_copyout_int(fd, buf, szp, t));
+}
+
+static void
+rep0_sock_send(void *arg, nni_aio *aio)
+{
+ rep0_sock *s = arg;
+
+ rep0_ctx_send(&s->ctx, aio);
+}
+
+static void
+rep0_sock_recv(void *arg, nni_aio *aio)
+{
+ rep0_sock *s = arg;
+
+ rep0_ctx_recv(&s->ctx, 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_size = sizeof(rep0_pipe),
+ .pipe_init = rep0_pipe_init,
+ .pipe_fini = rep0_pipe_fini,
+ .pipe_start = rep0_pipe_start,
+ .pipe_close = rep0_pipe_close,
+ .pipe_stop = rep0_pipe_stop,
+};
+
+static nni_proto_ctx_ops rep0_ctx_ops = {
+ .ctx_size = sizeof(rep0_ctx),
+ .ctx_init = rep0_ctx_init,
+ .ctx_fini = rep0_ctx_fini,
+ .ctx_send = rep0_ctx_send,
+ .ctx_recv = rep0_ctx_recv,
+};
+
+static nni_option rep0_sock_options[] = {
+ {
+ .o_name = NNG_OPT_MAXTTL,
+ .o_get = rep0_sock_get_max_ttl,
+ .o_set = rep0_sock_set_max_ttl,
+ },
+ {
+ .o_name = NNG_OPT_RECVFD,
+ .o_get = rep0_sock_get_recvfd,
+ },
+ {
+ .o_name = NNG_OPT_SENDFD,
+ .o_get = rep0_sock_get_sendfd,
+ },
+ // terminate list
+ {
+ .o_name = NULL,
+ },
+};
+
+static nni_proto_sock_ops rep0_sock_ops = {
+ .sock_size = sizeof(rep0_sock),
+ .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_send = rep0_sock_send,
+ .sock_recv = rep0_sock_recv,
+};
+
+static nni_proto rep0_proto = {
+ .proto_version = NNI_PROTOCOL_VERSION,
+ .proto_self = { NNG_REP0_SELF, NNG_REP0_SELF_NAME },
+ .proto_peer = { NNG_REP0_PEER, NNG_REP0_PEER_NAME },
+ .proto_flags = NNI_PROTO_FLAG_SNDRCV,
+ .proto_sock_ops = &rep0_sock_ops,
+ .proto_pipe_ops = &rep0_pipe_ops,
+ .proto_ctx_ops = &rep0_ctx_ops,
+};
+
+int
+nng_rep0_open(nng_socket *sidp)
+{
+ return (nni_proto_open(sidp, &rep0_proto));
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2026-01-18 22:14:19 +0000