diff options
Diffstat (limited to 'src/conn.cpp')
| -rw-r--r-- | src/conn.cpp | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/src/conn.cpp b/src/conn.cpp new file mode 100644 index 0000000..b323340 --- /dev/null +++ b/src/conn.cpp @@ -0,0 +1,277 @@ +/** + * Copyright (c) 2018 Cornell University. + * + * Author: Ted Yin <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining a copy of + * this software and associated documentation files (the "Software"), to deal in + * the Software without restriction, including without limitation the rights to + * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is furnished to do + * so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include <cstring> +#include <cassert> +#include <sys/types.h> +#include <sys/socket.h> +#include <netinet/tcp.h> +#include <fcntl.h> +#include <unistd.h> + +#include "salticidae/util.h" +#include "salticidae/conn.h" + +namespace salticidae { + +ConnPool::Conn::operator std::string() const { + return "<Conn fd=" + std::to_string(fd) + " " + + "addr=" + std::string(addr).c_str() + " " + + "mode=" + ((mode == Conn::ACTIVE) ? "active" : "passive") + + ">"; +} + +void ConnPool::Conn::send_data(evutil_socket_t fd, short events) { + if (!(events & EV_WRITE)) return; + auto conn = self(); /* pin the connection */ + ssize_t ret = BUFF_SEG_SIZE; + while (ret == BUFF_SEG_SIZE) + { + if (!send_buffer.size()) /* nothing to write */ + break; + bytearray_t buff_seg = send_buffer.pop(BUFF_SEG_SIZE); + ssize_t size = buff_seg.size(); + ret = send(fd, buff_seg.data(), size, MSG_NOSIGNAL); + SALTICIDAE_LOG_DEBUG("socket sent %d bytes", ret); + if (ret < size) + { + if (ret < 0) /* nothing is sent */ + { + /* rewind the whole buff_seg */ + send_buffer.push(std::move(buff_seg)); + if (errno != EWOULDBLOCK) + { + SALTICIDAE_LOG_INFO("reason: %s", strerror(errno)); + terminate(); + return; + } + } + else + { + /* rewind the leftover */ + bytearray_t left_over; + left_over.resize(size - ret); + memmove(left_over.data(), buff_seg.data() + ret, size - ret); + send_buffer.push(std::move(left_over)); + } + /* wait for the next write callback */ + ready_send = false; + ev_write.add(); + return; + } + } + /* consumed the buffer but endpoint still seems to be writable */ + ready_send = true; +} + +void ConnPool::Conn::recv_data(evutil_socket_t fd, short events) { + if (!(events & EV_READ)) return; + auto conn = self(); /* pin the connection */ + ssize_t ret = BUFF_SEG_SIZE; + while (ret == BUFF_SEG_SIZE) + { + bytearray_t buff_seg; + buff_seg.resize(BUFF_SEG_SIZE); + ret = recv(fd, buff_seg.data(), BUFF_SEG_SIZE, 0); + SALTICIDAE_LOG_DEBUG("socket read %d bytes", ret); + if (ret <= 0) + { + if (ret < 0 && errno != EWOULDBLOCK) + { + SALTICIDAE_LOG_INFO("reason: %s", strerror(errno)); + /* connection err or half-opened connection */ + terminate(); + return; + } + if (ret == 0) + { + terminate(); + return; + } + + /* EWOULDBLOCK */ + break; + } + buff_seg.resize(ret); + recv_buffer.push(std::move(buff_seg)); + } + ev_read.add(); + on_read(); +} + +void ConnPool::accept_client(evutil_socket_t fd, short) { + int client_fd; + struct sockaddr client_addr; + socklen_t addr_size = sizeof(struct sockaddr_in); + if ((client_fd = accept(fd, &client_addr, &addr_size)) < 0) + SALTICIDAE_LOG_ERROR("error while accepting the connection"); + else + { + int one = 1; + if (setsockopt(client_fd, SOL_TCP, TCP_NODELAY, (const char *)&one, sizeof(one)) < 0) + throw ConnPoolError(std::string("setsockopt failed")); + if (fcntl(client_fd, F_SETFL, O_NONBLOCK) == -1) + throw ConnPoolError(std::string("unable to set nonblocking socket")); + + NetAddr addr((struct sockaddr_in *)&client_addr); + conn_t conn = create_conn(); + Conn *conn_ptr = conn; + conn->fd = client_fd; + conn->cpool = this; + conn->mode = Conn::PASSIVE; + conn->addr = addr; + conn->ev_read = Event(eb, client_fd, EV_READ, + std::bind(&Conn::recv_data, conn_ptr, _1, _2)); + conn->ev_write = Event(eb, client_fd, EV_WRITE, + std::bind(&Conn::send_data, conn_ptr, _1, _2)); + conn->ev_read.add(); + conn->ev_write.add(); + conn->ready_send = false; + add_conn(conn); + SALTICIDAE_LOG_INFO("created connection %s", std::string(*conn).c_str()); + conn->on_setup(); + } + ev_listen.add(); +} + +void ConnPool::Conn::conn_server(evutil_socket_t fd, short events) { + auto conn = self(); /* pin the connection */ + if (send(fd, "", 0, MSG_NOSIGNAL) == 0) + { + ev_read = Event(cpool->eb, fd, EV_READ, + std::bind(&Conn::recv_data, this, _1, _2)); + ev_write = Event(cpool->eb, fd, EV_WRITE, + std::bind(&Conn::send_data, this, _1, _2)); + ev_read.add(); + ev_write.add(); + ev_connect.clear(); + ready_send = false; + SALTICIDAE_LOG_INFO("connected to peer %s", std::string(*this).c_str()); + on_setup(); + } + else + { + if (events & EV_TIMEOUT) + SALTICIDAE_LOG_INFO("%s connect timeout", std::string(*this).c_str()); + terminate(); + return; + } +} + +void ConnPool::init(NetAddr listen_addr) { + int one = 1; + if ((listen_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) + throw ConnPoolError(std::string("cannot create socket for listening")); + if (setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&one, sizeof(one)) < 0 || + setsockopt(listen_fd, SOL_TCP, TCP_NODELAY, (const char *)&one, sizeof(one)) < 0) + throw ConnPoolError(std::string("setsockopt failed")); + if (fcntl(listen_fd, F_SETFL, O_NONBLOCK) == -1) + throw ConnPoolError(std::string("unable to set nonblocking socket")); + + struct sockaddr_in sockin; + memset(&sockin, 0, sizeof(struct sockaddr_in)); + sockin.sin_family = AF_INET; + sockin.sin_addr.s_addr = INADDR_ANY; + sockin.sin_port = listen_addr.port; + + if (bind(listen_fd, (struct sockaddr *)&sockin, sizeof(sockin)) < 0) + throw ConnPoolError(std::string("binding error")); + if (::listen(listen_fd, MAX_LISTEN_BACKLOG) < 0) + throw ConnPoolError(std::string("listen error")); + ev_listen = Event(eb, listen_fd, EV_READ, + std::bind(&ConnPool::accept_client, this, _1, _2)); + ev_listen.add(); + SALTICIDAE_LOG_INFO("listening to %u", ntohs(listen_addr.port)); +} + +void ConnPool::Conn::terminate() { + auto &pool = cpool->pool; + auto it = pool.find(fd); + if (it != pool.end()) + { + /* temporarily pin the conn before it dies */ + auto conn = it->second; + assert(conn == this); + pool.erase(it); + close(); + /* inform the upper layer the connection will be destroyed */ + on_teardown(); + conn->self_ref = nullptr; /* remove the self-cycle */ + } +} + +void ConnPool::Conn::try_conn(evutil_socket_t, short) { + auto conn = self(); /* pin the connection */ + struct sockaddr_in sockin; + memset(&sockin, 0, sizeof(struct sockaddr_in)); + sockin.sin_family = AF_INET; + sockin.sin_addr.s_addr = addr.ip; + sockin.sin_port = addr.port; + + if (connect(fd, (struct sockaddr *)&sockin, + sizeof(struct sockaddr_in)) < 0 && errno != EINPROGRESS) + { + SALTICIDAE_LOG_INFO("cannot connect to %s", std::string(addr).c_str()); + terminate(); + return; + } + ev_connect = Event(cpool->eb, fd, EV_WRITE, + std::bind(&Conn::conn_server, this, _1, _2)); + ev_connect.add_with_timeout(CONN_SERVER_TIMEOUT); +} + +ConnPool::conn_t ConnPool::create_conn(const NetAddr &addr) { + int fd; + int one = 1; + if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) + throw ConnPoolError(std::string("cannot create socket for remote")); + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&one, sizeof(one)) < 0 || + setsockopt(fd, SOL_TCP, TCP_NODELAY, (const char *)&one, sizeof(one)) < 0) + throw ConnPoolError(std::string("setsockopt failed")); + if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) + throw ConnPoolError(std::string("unable to set nonblocking socket")); + conn_t conn = create_conn(); + Conn * conn_ptr = conn; + conn->fd = fd; + conn->cpool = this; + conn->mode = Conn::ACTIVE; + conn->addr = addr; + conn->ev_connect = Event(eb, -1, 0, std::bind(&Conn::try_conn, conn_ptr, _1, _2)); + conn->ev_connect.add_with_timeout(gen_rand_timeout(TRY_CONN_DELAY)); + add_conn(conn); + SALTICIDAE_LOG_INFO("created connection %s", std::string(*conn).c_str()); + return conn; +} + +ConnPool::conn_t ConnPool::add_conn(conn_t conn) { + auto it = pool.find(conn->fd); + if (it != pool.end()) + { + auto old_conn = it->second; + old_conn->terminate(); + } + return pool.insert(std::make_pair(conn->fd, conn)).first->second; +} + +} |