You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

160 lines
3.8 KiB

/* echosrv: a simple line echo server with optional prefix adding.
*
* echsrv --listen localhost6:1234 --prefix "ssl: "
*
* This will bind to 1234, and echo every line pre-pending "ssl: ". This is
* used for testing: we create several such servers with different prefixes,
* then we connect test clients that can then check they get the proper data
* back (thus testing that shoveling works both ways) with the correct prefix
* (thus testing it connected to the expected service).
* **/
#define _GNU_SOURCE
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <pwd.h>
#include <syslog.h>
#include <libgen.h>
#include <getopt.h>
#include "common.h"
/* Added to make the code compilable under CYGWIN
* */
#ifndef SA_NOCLDWAIT
#define SA_NOCLDWAIT 0
#endif
const char* USAGE_STRING =
"echosrv\n" \
"usage:\n" \
"\techosrv [-v] --listen <address:port> [--prefix <prefix>]\n"
"-v: verbose\n" \
"--listen: address to listen on. Can be specified multiple times.\n" \
"--prefix: add specified prefix before every line echoed.\n"
"";
const char* server_type = "echsrv"; /* keep setup_syslog happy */
/*
* Settings that depend on the command line.
*/
char* prefix = "";
int port;
void parse_cmdline(int argc, char* argv[])
{
int c;
struct option options[] = {
{ "verbose", no_argument, &verbose, 1 },
{ "numeric", no_argument, &numeric, 1 },
{ "listen", required_argument, 0, 'l' },
{ "prefix", required_argument, 0, 'p' },
};
struct addrinfo **a;
while ((c = getopt_long_only(argc, argv, "l:p:", options, NULL)) != -1) {
if (c == 0) continue;
switch (c) {
case 'l':
/* find the end of the listen list */
for (a = &addr_listen; *a; a = &((*a)->ai_next));
/* append the specified addresses */
resolve_name(a, optarg);
break;
case 'p':
prefix = optarg;
break;
default:
fprintf(stderr, "%s", USAGE_STRING);
exit(2);
}
}
if (!addr_listen) {
fprintf(stderr, "No listening port specified\n");
exit(1);
}
}
void start_echo(int fd)
{
int res;
char buffer[1 << 20];
int ret, prefix_len;
prefix_len = strlen(prefix);
memset(buffer, 0, sizeof(buffer));
strcpy(buffer, prefix);
while (1) {
ret = read(fd, buffer + prefix_len, sizeof(buffer));
if (ret == -1) {
fprintf(stderr, "%s", strerror(errno));
return;
}
res = write(fd, buffer, ret + prefix_len);
if (res < 0) {
fprintf(stderr, "%s", strerror(errno));
return;
}
}
}
void main_loop(int listen_sockets[], int num_addr_listen)
{
int in_socket, i;
for (i = 0; i < num_addr_listen; i++) {
if (!fork()) {
while (1)
{
in_socket = accept(listen_sockets[i], 0, 0);
if (verbose) fprintf(stderr, "accepted fd %d\n", in_socket);
if (!fork())
{
close(listen_sockets[i]);
start_echo(in_socket);
exit(0);
}
close(in_socket);
}
}
}
wait(NULL);
}
int main(int argc, char *argv[])
{
extern char *optarg;
extern int optind;
int num_addr_listen;
int *listen_sockets;
parse_cmdline(argc, argv);
num_addr_listen = start_listen_sockets(&listen_sockets, addr_listen);
main_loop(listen_sockets, num_addr_listen);
return 0;
}