1 files changed, 223 insertions, 0 deletions

diff --git a/vchat-connection.c b/vchat-connection.c
new file mode 100644
index 0000000..e3d79e9
--- /dev/null
+++ b/vchat-connection.c
@@ -0,0 +1,223 @@
+/*
+ * vchat-client - alpha version
+ * vchat-connection.c - handling of server connection and tls library dispatch
+ *
+ * Copyright (C) 2022 Dirk Engling <erdgeist@erdgeist.org>
+ *
+ * This program is free software. It can be redistributed and/or modified,
+ * provided that this copyright notice is kept intact. This program is
+ * distributed in the hope that it will be useful, but without any warranty;
+ * without even the implied warranty of merchantability or fitness for a
+ * particular purpose. In no event shall the copyright holder be liable for
+ * any direct, indirect, incidental or special damages arising in any way out
+ * of the use of this software. 
+ *
+ */
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+/* For tilde_expand */
+#include <readline/readline.h>
+
+#include "vchat.h"
+#include "vchat-connection.h"
+#include "vchat-tls.h"
+
+static int serverfd = -1;
+unsigned int want_tcp_keepalive = 0;
+
+/* Generic tcp connector, blocking */
+static int connect_tcp_socket( const char *server, const char *port ) {
+  struct addrinfo hints, *res, *res0;
+  int s, error;
+
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = PF_UNSPEC;
+  hints.ai_socktype = SOCK_STREAM;
+  error = getaddrinfo( server, port, &hints, &res0 );
+  if (error) return -1;
+  s = -1;
+  for (res = res0; res; res = res->ai_next) {
+    s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+    if (s < 0) continue;
+    if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
+      close(s);
+      s = -1;
+      continue;
+    }
+    break;  /* okay we got one */
+  }
+  freeaddrinfo(res0);
+
+  if (want_tcp_keepalive) {
+    int one=1;
+    setsockopt(s,SOL_SOCKET,SO_KEEPALIVE,&one,sizeof(one));
+  }
+  return s;
+}
+
+/* Return a tilde expanded path in a malloced buffer or NULL */
+static char *get_tilde_expanded(confopt opt) {
+  char *str = getstroption (opt);
+  if (!str)
+    return str;
+  if (str[0] == '~')
+    return tilde_expand (str);
+  return strdup(str);
+}
+
+/* connects to server */
+int
+vc_connect (const char *server, const char *port)
+{
+  /* vchat connection x509 store */
+  vc_x509store_t *vc_store;
+
+  /* pointer to tilde-expanded certificate/keyfile-names */
+  char *certfile = NULL;
+
+  /* Connect to the server */
+  serverfd = connect_tcp_socket( server, port );
+  if( serverfd < 0 ) {
+    /* inform user */
+    snprintf (tmpstr, TMPSTRSIZE, getformatstr(FS_CANTCONNECT), server, port );
+    writechan (tmpstr);
+    return -1;
+  }
+
+  if (!getintoption(CF_USESSL))
+    return 0;
+
+  /* If SSL is requested, get our ssl-BIO running */
+  vc_store = vc_init_x509store();
+  if( !vc_store ) {
+      snprintf (tmpstr, TMPSTRSIZE, getformatstr(FS_ERR), "Out of memory" );
+      writechan (tmpstr);
+      return -1;
+  }
+
+  /* get name of certificate file */
+  certfile = get_tilde_expanded (CF_CERTFILE);
+  /* do we have a certificate file? */
+  if (certfile) {
+    /* get name of key file */
+    char *keyfile = get_tilde_expanded (CF_KEYFILE);
+
+    vc_x509store_setflags(vc_store, VC_X509S_USE_CERTIFICATE);
+    vc_x509store_setcertfile(vc_store, certfile);
+
+    vc_x509store_set_pkeycb(vc_store, (vc_askpass_cb_t)passprompt);
+    /* if we don't have a key file, the key may be in the cert file */
+    vc_x509store_setkeyfile(vc_store, keyfile ? keyfile : certfile);
+
+    free(keyfile);
+    free(certfile);
+  }
+
+  if (getintoption(CF_VERIFYSSL)) {
+      /* get name of key file */
+      char *cafile = get_tilde_expanded (CF_CAFILE);
+      if (cafile) {
+        vc_x509store_setflags(vc_store, VC_X509S_NODEF_CAFILE);
+        vc_x509store_setcafile(vc_store, cafile);
+      }
+      vc_x509store_setflags(vc_store, VC_X509S_SSL_VERIFY_PEER);
+      free(cafile);
+  }
+
+  /* upgrade our plain BIO to ssl */
+  int result = vc_tls_connect( serverfd, vc_store );
+  vc_cleanup_x509store(vc_store);
+
+  if (result) {
+    close(serverfd);
+    serverfd = -1;
+    errno = EIO;
+    snprintf (tmpstr, TMPSTRSIZE, getformatstr(FS_CANTCONNECT), server, port );
+    writechan (tmpstr);
+    return -1;
+  }
+
+  /* inform user */
+  snprintf (tmpstr, TMPSTRSIZE, getformatstr(FS_CONNECTED), server, port);
+  writechan (tmpstr);
+
+#ifdef DEBUG
+  dumpfile = fopen( "dumpfile", "a");
+#endif
+
+  /* if we didn't fail until now, we've got a connection. */
+  return 0;
+}
+
+/* Poll for activity on the socket or stdin */
+int vc_poll (int timeout_seconds) {
+  fd_set readfds;
+  FD_ZERO (&readfds);
+  FD_SET (0, &readfds);
+  if (serverfd != -1)
+    FD_SET (serverfd, &readfds);
+  struct timeval tv = { timeout_seconds, 0};
+  int result = select (serverfd + 2, &readfds, NULL, NULL, &tv);
+  if (result <= 0)
+    return result;
+  result = FD_ISSET (0, &readfds) ? 1 : 0;
+  if (serverfd != -1)
+    result += FD_ISSET (serverfd, &readfds) ? 2 : 0;
+  return result;
+}
+
+/* disconnect from server */
+void
+vc_disconnect () {
+  if (serverfd > 0) {
+    close(serverfd);
+    serverfd = -1;
+  }
+  vc_tls_cleanup();
+  loggedin = 0;
+}
+
+void
+vc_sendmessage (const char *msg)
+{
+#ifdef DEBUG
+  /* debugging? log network output! */
+  fprintf (dumpfile, ">| %s (%zd)\n", msg, strlen(msg));
+#endif
+
+  if (getintoption(CF_USESSL)) {
+    /* send data to server */
+    if (vc_tls_sendmessage (msg, strlen (msg)) != strlen (msg))
+      writecf (FS_ERR,"Message sending fuzzy.");
+
+    /* send line termination to server */
+    if (vc_tls_sendmessage ("\r\n", 2) != 2)
+      writecf (FS_ERR,"Message sending fuzzy.");
+  } else {
+    /* send data to server */
+    if (write (serverfd, msg, strlen (msg)) != strlen (msg))
+      writecf (FS_ERR,"Message sending fuzzy.");
+
+    /* send line termination to server */
+    if (write (serverfd, "\r\n", 2) != 2)
+      writecf (FS_ERR,"Message sending fuzzy.");
+  }
+}
+
+ssize_t
+vc_receivemessage (char *buffer, size_t size) {
+  if (getintoption(CF_USESSL))
+    return vc_tls_receivemessage (buffer, size);
+  else
+    return read(serverfd, buffer, size);
+}