From 62bc1af6c6a1201db551e1ec523e757415464fd5 Mon Sep 17 00:00:00 2001
From: root <root@nolonger-other.tetra.james.local>
Date: Sun, 25 Oct 2020 13:26:29 +0000
Subject: tidy up, make less awful

---
 util.c | 306 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 306 insertions(+)
 create mode 100644 util.c

(limited to 'util.c')

diff --git a/util.c b/util.c
new file mode 100644
index 0000000..95268b4
--- /dev/null
+++ b/util.c
@@ -0,0 +1,306 @@
+#include <string.h>
+#include <unistd.h>
+#include <termio.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+
+
+
+#include "util.h"
+
+
+void
+set_nonblocking (int fd)
+{
+  long arg = 0;
+  arg = fcntl (fd, F_GETFL, arg);
+  arg |= O_NONBLOCK;
+  fcntl (fd, F_SETFL, arg);
+}
+
+void
+set_blocking (int fd)
+{
+  long arg = 0;
+  arg = fcntl (fd, F_GETFL, arg);
+  arg &= ~O_NONBLOCK;
+  fcntl (fd, F_SETFL, arg);
+}
+
+int fd_can_read (int fd)
+{
+  struct timeval tv = {0};
+  fd_set rfds;
+  FD_ZERO (&rfds);
+  FD_SET (fd, &rfds);
+
+  if (select (fd + 1, &rfds, NULL, NULL, &tv) == 1)
+    return 1;
+
+  return 0;
+}
+
+int fd_drain (int fd)
+{
+  char c;
+
+  while (fd_can_read (fd))
+    if (read (fd, &c, 1) != 1) return -1;
+
+
+  return 0;
+}
+
+
+static speed_t
+baud_to_speed_t (int baud)
+{
+  switch (baud) {
+#ifdef B0
+
+  case 0:
+    return B0;
+#endif
+#ifdef B50
+
+  case 50:
+    return B50;
+#endif
+#ifdef B75
+
+  case 75:
+    return B75;
+#endif
+#ifdef B110
+
+  case 110:
+    return B110;
+#endif
+#ifdef B134
+
+  case 134:
+    return B134;
+#endif
+#ifdef B150
+
+  case 150:
+    return B150;
+#endif
+#ifdef B200
+
+  case 200:
+    return B200;
+#endif
+#ifdef B300
+
+  case 300:
+    return B300;
+#endif
+#ifdef B600
+
+  case 600:
+    return B600;
+#endif
+#ifdef B1200
+
+  case 1200:
+    return B1200;
+#endif
+#ifdef B1800
+
+  case 1800:
+    return B1800;
+#endif
+#ifdef B2400
+
+  case 2400:
+    return B2400;
+#endif
+#ifdef B4800
+
+  case 4800:
+    return B4800;
+#endif
+#ifdef B9600
+
+  case 9600:
+    return B9600;
+#endif
+#ifdef B19200
+
+  case 19200:
+    return B19200;
+#endif
+#ifdef B38400
+
+  case 38400:
+    return B38400;
+#endif
+#ifdef B57600
+
+  case 57600:
+    return B57600;
+#endif
+#ifdef B115200
+
+  case 115200:
+    return B115200;
+#endif
+#ifdef B230400
+
+  case 230400:
+    return B230400;
+#endif
+  }
+
+  return -1;
+}
+
+
+
+static void
+default_termios (struct termios *termios)
+{
+  termios->c_iflag = 0;
+  termios->c_oflag = NL0 | CR0 | TAB0 | BS0 | VT0 | FF0;
+  termios->c_lflag = 0;
+  termios->c_cflag = CS8 | CREAD | CLOCAL;
+
+  termios->c_cc[VINTR] = 003;
+  termios->c_cc[VQUIT] = 034;
+  termios->c_cc[VERASE] = 0177;
+  termios->c_cc[VKILL] = 025;
+  termios->c_cc[VEOF] = 004;
+  termios->c_cc[VEOL] = 0;
+  termios->c_cc[VEOL2] = 0;
+  termios->c_cc[VSTART] = 021;
+  termios->c_cc[VSTOP] = 023;
+  termios->c_cc[VSUSP] = 032;
+  termios->c_cc[VLNEXT] = 026;
+  termios->c_cc[VWERASE] = 027;
+  termios->c_cc[VREPRINT] = 022;
+  termios->c_cc[VDISCARD] = 017;
+
+
+}
+
+
+//XXX: no locks
+
+int open_tty (const char *path, int baud)
+{
+  int fd;
+  struct termios termios;
+  speed_t s = baud_to_speed_t (baud);
+
+  if (s == (speed_t) -1) return -1;
+
+
+  fd = open (path, O_RDWR | O_NOCTTY | O_NONBLOCK);
+
+
+  if (tcgetattr (fd, &termios)) {
+    close (fd);
+    return -1;
+  }
+
+  default_termios (&termios);
+
+  if (tcsetattr (fd, TCSANOW, &termios)) {
+    close (fd);
+    return -1;
+  }
+
+  cfsetispeed (&termios, s);
+  cfsetospeed (&termios, s);
+
+  return fd;
+}
+
+
+
+static int host_to_sin (const char *host, struct sockaddr_in *sin)
+{
+
+  struct hostent *he = gethostbyname2 (host, AF_INET);
+
+  if (!he) {
+    if (!inet_aton (host, &sin->sin_addr))
+      return -1;
+
+    return 0;
+  }
+
+  if (he->h_addrtype != AF_INET)
+    return -1;
+
+  sin->sin_family = AF_INET;
+
+  memcpy (&sin->sin_addr, he->h_addr_list[0], he->h_length);
+
+  return 0;
+}
+
+
+int open_tcp_client (const char *host, unsigned port)
+{
+  struct sockaddr_in sin = {0};
+  int fd;
+
+
+  if (host_to_sin (host, &sin))
+    return -1;
+
+
+  fd = socket (PF_INET, SOCK_STREAM, 0);
+
+  if (fd < 0) return -1;
+
+  sin.sin_port = htons (port);
+
+  if (connect (fd, (struct sockaddr *)&sin, sizeof (sin))) {
+    close (fd);
+    return -1;
+  }
+
+  return fd;
+}
+
+int open_tcp_server (unsigned port)
+{
+  int fd;
+  int enable = 1;
+  struct sockaddr_in sin = {0};
+
+  fd = socket (PF_INET, SOCK_STREAM, 0);
+
+  if (fd < 0) return -1;
+
+  if (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof (enable)))
+    return -1;
+
+  sin.sin_family = AF_INET;
+  sin.sin_port = htons (port);
+  sin.sin_addr.s_addr = INADDR_ANY;
+
+  if (bind (fd, (struct sockaddr *)&sin, sizeof (sin))) {
+    close (fd);
+    return -1;
+  }
+
+  if (listen (fd, 5)) {
+    close (fd);
+    return -1;
+  }
+
+  return fd;
+}
+
+
+
+
-- 
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