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/* portecho.c
*
* by Gnther Montag dl4mge
* test program for telnet port, it uses "toupper"
* and just echoes the input in capitals.
* derived from tfwd.c, which is taken from the
* very interesting select_tut man page (see man select_tut).
*
* This is part of hf package, GPL. Have fun!
*/
/* ----------------------------------------------------------------- */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <string.h>
#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <ctype.h>
#undef max
#define max(x,y) ((x) > (y) ? (x) : (y))
#define SHUT_FD1 { \
if (fd1 >= 0) { \
shutdown (fd1, SHUT_RDWR); \
close (fd1); \
fd1 = -1; \
} \
}
#define BUF_SIZE 1024
int quit = 0;
char* greeting = "Connected to portecho!\nQuit me by #.\n";
char* byebye = "Bye ! \n";
/* ----------------------------------------------------------------- */
static int listen_socket (int listen_port) {
struct sockaddr_in a;
int s;
int yes;
if ((s = socket (AF_INET, SOCK_STREAM, 0)) < 0) {
perror ("socket");
return -1;
}
yes = 1;
if (setsockopt
(s, SOL_SOCKET, SO_REUSEADDR,
(char *) &yes, sizeof (yes)) < 0) {
perror ("setsockopt");
close (s);
return -1;
}
memset (&a, 0, sizeof (a));
a.sin_port = htons (listen_port);
a.sin_family = AF_INET;
if (bind
(s, (struct sockaddr *) &a, sizeof (a)) < 0) {
perror ("bind");
close (s);
return -1;
}
printf ("accepting connections on port %d\n",
(int) listen_port);
listen (s, 10);
return s;
}
/* ----------------------------------------------------------------- */
int main (int argc, char **argv) {
int h, i, fd1 = -1;
char buf1[BUF_SIZE], buf2[BUF_SIZE];
// buf1 what port reads from extern prog = tx
// buf2 what port sends to extern prog = rx
int buf1_avail = 0, buf1_written = 0;
int buf2_avail = 0, buf2_written = 0;
// vars of my test prog
char zeichen;
char quitsignal = '#';
if (argc != 2) {
fprintf (stderr,
"\n\t* * * dl4mge 's PORTECHO. Little TCP test program * * *\n"
"\t* * * for tests with hf's mailbox function. * * *\n"
"\n"
"\tUsage: portecho <port>, e.g. 'portecho 3333'.\n"
"\tQuit me with '#'. \n\n");
// <forward-to-port> <forward-to-ip-address>\n");
exit (1);
}
fprintf (stdout,
"\n\t* * * dl4mge 's PORTECHO. Little TCP test program * * *\n"
"\t* * * for tests with hf's mailbox function. * * *\n"
"\n"
"\tTest me on another console by 'telnet localhost <port>'.\n"
"\tQuit me with '#'. \n\n");
signal (SIGPIPE, SIG_IGN);
h = listen_socket (atoi (argv[1]));
if (h < 0) {
fprintf (stderr, "error on opening port\n");
exit (1);
}
for (;;) {
for (;;) {
int r, n = 0;
fd_set rd, wr, er;
FD_ZERO (&rd);
FD_ZERO (&wr);
FD_ZERO (&er);
FD_SET (h, &rd);
n = max (n, h);
if (fd1 > 0 && buf1_avail < BUF_SIZE) {
fprintf (stderr, "testport ready for read\n");
FD_SET (fd1, &rd);
n = max (n, fd1);
}
if (fd1 > 0
&& buf2_avail - buf2_written > 0) {
fprintf (stderr, "testport ready for write\n");
FD_SET (fd1, &wr);
n = max (n, fd1);
}
if (fd1 > 0) {
fprintf (stderr, "testport ready for err\n");
FD_SET (fd1, &er);
n = max (n, fd1);
}
r = select (n + 1, &rd, &wr, &er, NULL);
if (r == -1 && errno == EINTR)
continue;
if (r < 0) {
perror ("select()");
exit (1);
}
if (FD_ISSET (h, &rd)) {
unsigned int l;
struct sockaddr_in client_address;
fprintf (stderr, "something tries to access port.\n");
memset (&client_address, 0, l =sizeof (client_address));
r = accept (h, (struct sockaddr *) &client_address, &l);
fprintf (stderr, "I will try to accept peer port\n");
if (r < 0) {
perror ("accept() peer port");
} else {
fprintf (stderr, "I accepted peer port\n");
fprintf (stderr, "r = %d\n",r);
SHUT_FD1;
buf1_avail = buf1_written = 0;
buf2_avail = buf2_written = 0;
fd1 = r;
sprintf(buf2, "%s", greeting);
buf2_avail = strlen(greeting);
}
}
// /* NB: read oob data before normal reads
if (fd1 > 0)
if (FD_ISSET (fd1, &er)) {
char c;
errno = 0;
r = recv (fd1, &c, 1, MSG_OOB);
if (r < 1) {
SHUT_FD1;
} else
fprintf (stderr, "error: %s, errno %d\n", &c, errno);
}
// READ
if (fd1 > 0) {
if (FD_ISSET (fd1, &rd)) {
fprintf (stderr, "try read\n");
r = read (fd1, buf1 + buf1_avail, BUF_SIZE - buf1_avail);
if (r < 1) {
SHUT_FD1;
} else {
buf1_avail += r;
fprintf (stderr, "read %d chars\n", r);
fprintf (stderr, "buf1: %s\n", buf1);
}
// PROCESS
for (i = 0; i < buf1_avail && i < (BUF_SIZE - buf2_avail); i++) {
zeichen = buf1[buf1_written++];
if (zeichen != quitsignal) {
buf2[buf2_avail++] = toupper(zeichen);
}
if (zeichen == quitsignal) {
fprintf (stderr,
"read: Signal to quit: %c !\n", zeichen);
quit = 1;
sprintf(buf2, "%s", byebye);
buf2_avail = strlen(byebye);
//exit(0);
}
}
fprintf (stderr, "buf2: %s\n", buf2);
}
}
// WRITE
if (fd1 > 0) {
if (FD_ISSET (fd1, &wr)) {
fprintf (stderr, "write\n");
r = write (fd1, buf2 + buf2_written,
buf2_avail - buf2_written);
if (r < 1) {
SHUT_FD1;
} else {
buf2_written += r;
}
}
}
// /* check if write data has caught read data
if (buf1_written == buf1_avail) {
buf1_written = buf1_avail = 0;
memset(buf1, 0, sizeof(buf1));
}
if (buf2_written == buf2_avail) {
buf2_written = buf2_avail = 0;
memset(buf2, 0, sizeof(buf2));
if (quit) {
SHUT_FD1
quit = 0;
break;
}
}
}
}
return 0;
}
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