From 4b4e4972088d82cac99941398834d8e6d661682c Mon Sep 17 00:00:00 2001
From: root <root@nolonger-other.tetra.james.local>
Date: Sun, 25 Oct 2020 01:08:03 +0000
Subject: fish

---
 rx.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 208 insertions(+)
 create mode 100644 rx.c

(limited to 'rx.c')

diff --git a/rx.c b/rx.c
new file mode 100644
index 0000000..a02c964
--- /dev/null
+++ b/rx.c
@@ -0,0 +1,208 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+
+
+void poll (int fd)
+{
+}
+
+int valid_fn (unsigned char fn)
+{
+  switch (fn) {
+  case 0x30:
+  case 0x31:
+  case 0x32:
+  case 0x33:
+  case 0x34:
+  case 0x35:
+  case 0x36:
+  case 0x37:
+  case 0x38:
+  case 0x08:
+  case 0x39:
+  case 0x09:
+  case 0x43:
+  case 0x45:
+  case 0x4E:
+  case 0x4F:
+  case 0x50:
+  case 0x40:
+  case 0x3F:
+  case 0x23:
+  case 0x26:
+  case 0x41:
+  case 0x58:
+  case 0x4C:
+  case 0x56:
+  case 0x76:
+  case 0x49:
+    return 1;
+  }
+
+  return 0;
+}
+
+
+void ack (int fd)
+{
+  char buf[3];
+
+  buf[0] = 0;
+  buf[1] = 0x38;
+  buf[2] = 0xff ^ buf[0] ^ buf[1];
+
+  write (fd, buf, sizeof (buf));
+
+}
+
+
+void msg (char *account, char *event, char *ascii)
+{
+  printf ("%s %64s %s\n", account, event, ascii);
+}
+
+
+int rx_pkt (int fd, unsigned char *pkt, unsigned len)
+{
+  unsigned char parity = 0xff;
+  unsigned i;
+
+  static char account[65];
+  static char event[65];
+  static char ascii[65];
+
+
+
+  for (i = 0; i < len; ++i)
+    parity ^= pkt[i];
+
+  if (parity) return -1;
+
+  len--;
+
+
+  switch (pkt[1]) {
+  case 0x23:
+    memcpy (account, &pkt[2], len - 2);
+    account[len - 2] = 0;
+    break;
+
+  case 0x4e:
+  case 0x4f:
+    memcpy (event, &pkt[2], len - 2);
+    event[len - 2] = 0;
+    break;
+
+  case 0x41:
+    memcpy (ascii, &pkt[2], len - 2);
+    ascii[len - 2] = 0;
+
+    msg (account, event, ascii);
+    break;
+  }
+
+
+  if (pkt[0] & 0x40) ack (fd);
+
+  return 0;
+}
+
+
+
+int rx (int fd)
+{
+  static unsigned char pkt[67];
+  static unsigned ptr;
+  unsigned char byte;
+  unsigned len;
+
+  if (read (fd, &byte, 1) != 1) {
+    ptr = 0;
+    return -1;
+  }
+
+  pkt[ptr++] = byte;
+
+  if (ptr > 2 && !valid_fn (pkt[1])) {
+    ptr = 0;
+    return 0;
+  }
+
+  len = pkt[0] & 0x3f;
+
+  if (ptr == (len + 3)) {
+    ptr = 0;
+    return rx_pkt (fd, pkt, len + 3);
+  }
+
+  return 0;
+}
+
+
+int main (int argc, char *argv)
+{
+  struct sockaddr_in sin;
+  struct timeval tv = {0};
+  int rc;
+  int fd;
+  int afd = -1;
+  fd_set rfds;
+  fd_set wfds;
+
+
+  fd = socket (PF_INET, SOCK_STREAM, 0);
+
+  sin.sin_family = AF_INET;
+  sin.sin_port = htons (10002);
+  sin.sin_addr.s_addr = INADDR_ANY;
+
+  bind (fd, (struct sockaddr *)&sin, sizeof (sin));
+
+  listen (fd, 5);
+
+  tv.tv_sec = 5;
+
+  FD_ZERO (&wfds);
+
+  for (;;) {
+
+    FD_ZERO (&rfds);
+
+    FD_SET (fd, &rfds);
+
+    if (afd > 0)
+      FD_SET (afd, &rfds);
+
+    rc = select (afd > fd ? afd + 1 : fd + 1, &rfds, &wfds, NULL, &tv);
+
+    if ((!rc)  && (afd > 0)) poll (afd);
+
+
+    if (FD_ISSET (fd, &rfds)) {
+      if (afd > 0) close (afd);
+
+      afd = accept (fd, NULL, NULL);
+    }
+
+    if ((afd > 0) && (FD_ISSET (afd, &rfds))) {
+      if (rx (afd)) {
+        close (afd);
+        afd = -1;
+      }
+    }
+
+    if (!tv.tv_sec && !tv.tv_usec)
+      tv.tv_sec = 5;
+
+
+
+
+  }
+}
+
-- 
cgit v1.2.3