first commit

1 files changed, 211 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..8555da1
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,211 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include <array.h>
+#include <better_string.h>
+#include <helpers.h>
+#include <opcodes.h>
+#include <protocol.h>
+
+int PORT = DEFAULT_PORT;
+int nfds = 1;
+struct pollfd fds[MAX_CONNECTIONS * 2];
+
+void handle_sigint(int sig) {
+  for (int i = 0; i < nfds; i++) {
+    if (fds[i].fd >= 0) {
+      close(fds[i].fd);
+    }
+  }
+
+  exit(0);
+}
+
+/* modifying function: modifies `in` to point to new location after opcode */
+int parse_op(char *in) {
+  char buf[MAX_OP_LEN];
+  buf[0] = '\0';
+
+  char cur;
+  cur = in[0];
+
+  bool found = false;
+  for (int i = 0; i < 11; i++) {
+    if (cur == '\t') {
+      found = true;
+      in++;
+      break;
+    } else if (cur == '\0') {
+      break;
+    }
+
+    buf[i] = in[0];
+    in++;
+    cur = in[0];
+  }
+
+  return found ? encode_client_opcode(buf) : CO_UNRECOGNIZED;
+}
+
+array_t *parse_args(char *buf) { return NULL; }
+
+void set_non_blocking(int sock) {
+  int flags = fcntl(sock, F_GETFL, 0);
+  int code = fcntl(sock, F_SETFL, flags | O_NONBLOCK);
+  die_lz(code, "fcntl()");
+}
+
+int main(int argc, char **argv) {
+  char buffer[MAX_BUFSIZE];
+  char res_buffer[MAX_BUFSIZE];
+  struct pollfd *local_fds1 = fds;
+  struct pollfd *local_fds2 = fds + MAX_CONNECTIONS;
+  struct pollfd *local_fds = local_fds1;
+
+  /* We start by initializing our net-related structs */
+  signal(SIGINT, handle_sigint);
+
+  int listen_sd = socket(AF_INET6, SOCK_STREAM, 0);
+  int optval = 1;
+  die_lz(listen_sd, "socket()");
+
+  int reuse = setsockopt(listen_sd, SOL_SOCKET, SO_REUSEADDR, (char *)&optval,
+                         sizeof(optval));
+  die_lz(reuse, "setsockopt()");
+
+  int nonblock = ioctl(listen_sd, FIONBIO, (char *)&optval);
+  die_lz(nonblock, "ioctl()");
+
+  set_non_blocking(listen_sd);
+
+  /* Make new address */
+  struct sockaddr_in6 addr;
+  alloc_zero(&addr, sizeof(addr));
+
+  addr.sin6_family = AF_INET6;
+  memcpy(&addr.sin6_addr, &in6addr_any, sizeof(in6addr_any));
+  addr.sin6_port = htons(DEFAULT_PORT);
+
+  int sock_bind = bind(listen_sd, (struct sockaddr *)&addr, sizeof(addr));
+  die_lz(sock_bind, "bind()");
+
+  int sock_listen = listen(listen_sd, 32);
+  die_lz(sock_listen, "listen()");
+
+  /*
+    The first fd entry is the listening socket for new connections;
+    all the rest are sockets we read from and write to. Whenever a client
+    connects, we know from the listening socket.
+  */
+
+  alloc_zero(fds, sizeof(fds));
+  fds[0].fd = listen_sd;
+  fds[0].events = POLLIN;
+
+  int timeout = 6000;
+  int sock_poll;
+  bool end_server = false;
+
+  /* mainloop */
+  do {
+    bool compress_array = false;
+    /*
+      if an fd loses connection, we want to remove all -1's from the fds array
+     */
+
+    sock_poll = poll(local_fds, nfds, timeout);
+    die_lz(sock_poll, "poll()");
+
+    for (int i = 0; i < nfds; i++) {
+      if (local_fds[i].revents == 0)
+        continue;
+
+      if (local_fds[i].revents != POLLIN) {
+        end_server = true;
+        break;
+      }
+
+      if (local_fds[i].fd == listen_sd) {
+        printf("socket is readable\n");
+        int new_sd;
+
+        do {
+          new_sd = accept(listen_sd, NULL, NULL);
+
+          if (new_sd < 0 && errno != EWOULDBLOCK) {
+            perror("accept() failed");
+            end_server = true;
+            break;
+          }
+
+          local_fds[nfds].fd = new_sd;
+          local_fds[nfds].events = POLLIN;
+          nfds++;
+        } while (new_sd >= 0);
+      } else {
+        bool close_conn = false;
+        int fd_recv;
+        int fd_send;
+        fd_recv = recv(local_fds[i].fd, buffer, sizeof(buffer), 0);
+
+        if (fd_recv < 0 && errno != EWOULDBLOCK) {
+          perror("recv() failed");
+          close_conn = true;
+        } else if (fd_recv == 0) {
+          printf("Connection closed\n");
+          close_conn = true;
+        } else {
+          /* echo server -- replace this with buffer parsing */
+          /* TODO: reply to client based on user input */
+          fd_send = send(local_fds[i].fd, buffer, fd_recv, 0);
+          if (fd_send < 0) {
+            perror("send()");
+            close_conn = true;
+          }
+        }
+
+        if (close_conn) {
+          close(local_fds[i].fd);
+          local_fds[i].fd = 0;
+          compress_array = true;
+        }
+      }
+    }
+
+    if (compress_array) {
+      printf("switching...\n");
+      int cur_nfds = nfds;
+      nfds = 0;
+      for (int i = 0; i < cur_nfds; i++) {
+	if (local_fds[i].fd != 0) {
+	  local_fds2[nfds] = local_fds[i];
+	  nfds ++;
+	}
+      }
+
+      local_fds1 = local_fds2;
+      local_fds2 = local_fds;
+      local_fds = local_fds1;
+      alloc_zero(local_fds2, MAX_CONNECTIONS);
+    }
+  } while (!end_server);
+
+  for (int i = 0; i < nfds; i++) {
+    if (fds[i].fd >= 0) {
+      close(fds[i].fd);
+    }
+  }
+
+  return 0;
+}