feat(lib/net): network library implemented

1 files changed, 88 insertions, 0 deletions

diff --git a/lib/net/server.c b/lib/net/server.c
new file mode 100644
index 0000000..a81a1d3
--- /dev/null
+++ b/lib/net/server.c
@@ -0,0 +1,88 @@
+#include "./server.h"
+#include "common.h"
+
+const uint32_t CONNECTION_QUEUE_LEN = 10U;
+
+server_t* server_init_tcp(const char* addr, const char* port) {
+    server_t* srv = calloc(1, sizeof(*srv));
+
+    srv->listen_socket_fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
+    if (srv->listen_socket_fd == -1) {
+        fprintf(stderr, "[server_init_tcp] Unable to create socket!\n");
+        exit(EXIT_FAILURE);
+    }
+
+    int setsockopt_yes = 1;
+    if (setsockopt(srv->listen_socket_fd, SOL_SOCKET, SO_REUSEADDR, &setsockopt_yes, sizeof(setsockopt_yes)) == -1) {
+        fprintf(stderr, "[server_init_tcp] Unable to set SO_REUSEADDR socket option\n");
+        exit(EXIT_FAILURE);
+    }
+
+    struct sockaddr_in* listen_addr = get_addr(addr, port);
+
+    if (bind(srv->listen_socket_fd, (struct sockaddr*) listen_addr, sizeof(*listen_addr)) == -1) {
+        fprintf(stderr, "[server_init_tcp] Unable to bind\n");
+        exit(EXIT_FAILURE);
+    }
+
+    free(listen_addr);
+
+    if (listen(srv->listen_socket_fd, CONNECTION_QUEUE_LEN) == -1) {
+        fprintf(stderr, "[server_init_tcp] Unable to listen() on a socket\n");
+        exit(EXIT_FAILURE);
+    }
+
+    struct linger linger_params = {.l_onoff = 1, .l_linger = 1};
+    if (setsockopt(srv->listen_socket_fd, SOL_SOCKET, SO_LINGER, &linger_params, sizeof(linger_params)) == -1) {
+        fprintf(stderr, "[conn_try_accept] Unable to modify SO_LINGER socket option\n");
+        exit(EXIT_FAILURE);
+    }
+
+    return srv;
+}
+
+void server_shutdown(server_t* srv) {
+    if (close(srv->listen_socket_fd) == -1) {
+        fprintf(stderr, "[server_shutdown] Unable to close listen socket\n");
+        exit(EXIT_FAILURE);
+    }
+}
+
+conn_t* conn_try_accept(server_t* srv) {
+    int client_socket_fd = accept4(srv->listen_socket_fd, NULL, NULL, SOCK_NONBLOCK);
+    if (client_socket_fd == -1) {
+        if (errno == EAGAIN || errno == EWOULDBLOCK) {
+            return NULL;
+        }
+
+        fprintf(stderr, "[conn_try_accept] Unable to accept() connection on a socket\n");
+        exit(EXIT_FAILURE);
+    }
+
+    conn_t* conn = calloc(1, sizeof(*conn));
+    conn->conn_socket_fd = client_socket_fd;
+
+    // Разрешаем "зависания сокета" для доотправки данных.
+
+    // Disable Nagle's algorithm:
+    int setsockopt_arg = 1;
+    if (setsockopt(conn->conn_socket_fd, IPPROTO_TCP, TCP_NODELAY, &setsockopt_arg, sizeof(setsockopt_arg)) == -1) {
+        fprintf(stderr, "[conn_try_accept] Unable to enable TCP_NODELAY socket option\n");
+        exit(EXIT_FAILURE);
+    }
+
+    // Disable corking:
+    setsockopt_arg = 0;
+    if (setsockopt(conn->conn_socket_fd, IPPROTO_TCP, TCP_CORK, &setsockopt_arg, sizeof(setsockopt_arg)) == -1) {
+        fprintf(stderr, "[conn_try_accept] Unable to disable TCP_CORK socket option\n");
+        exit(EXIT_FAILURE);
+    }
+
+    if (conn_configure_tcpalive(conn) == -1) {
+        fprintf(stderr, "[conn_try_accept] Unable to enable TCPALIVE\n");
+        exit(EXIT_FAILURE);
+    }
+
+    printf("[conn_try_accept] new client connected\n");
+    return conn;
+}