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#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <netdb.h>
#include "netlink.h"
#include "proto.h"
#include "ring.h"
/* In Linux, this is an enum */
#if defined(__linux__) || defined(IPPROTO_IP)
#define HAS_IPPROTO_IP
#endif
netlink nlink;
class netchannel : public ringbuf::source {
public:
virtual int read(char *buf, int maxlen) {
int net = nlink.getfd();
int l = recv(net, buf, maxlen, 0);
if (l<0 && errno == EWOULDBLOCK) l = 0;
return l;
}
};
class netchannel2 : public datasink {
public:
virtual int write(const char *buf, int len) {
int r = nlink.send(buf, len, 0);
if (r==-1 && (errno==ENOBUFS || errno==EWOULDBLOCK)) return 0;
return r;
}
virtual int writeurg(const char *buf, int len) {
/*
* In 4.2 (and 4.3) systems, there is some question about
* what byte in a sendOOB operation is the "OOB" data.
* To make ourselves compatible, we only send ONE byte
* out of band, the one WE THINK should be OOB (though
* we really have more the TCP philosophy of urgent data
* rather than the Unix philosophy of OOB data).
*/
if (len==0) return 0;
int r = nlink.send(buf, 1, MSG_OOB);
if (r==-1 && (errno==ENOBUFS || errno==EWOULDBLOCK)) r = 0;
if (r<=0) return r;
int rr = nlink.send(buf+1, len-r, 0);
if (rr==-1 && (errno==ENOBUFS || errno==EWOULDBLOCK)) rr = 0;
if (rr<=0) return r; /* less than ideal */
return r+rr;
}
};
static netchannel chan;
static netchannel2 chan2;
datasink *netsink = &chan2;
ringbuf::source *netsrc = &chan;
netlink::netlink() { net = -1; }
netlink::~netlink() { ::close(net); }
int netlink::setdebug(int debug) {
if (net > 0 &&
(setsockopt(net, SOL_SOCKET, SO_DEBUG, &debug, sizeof(debug))) < 0) {
perror("setsockopt (SO_DEBUG)");
}
return 1;
}
void netlink::close(int doshutdown) {
if (doshutdown) {
shutdown(net, 2);
}
::close(net);
}
int netlink::connect(int debug, struct addrinfo *addr,
char *srcroute, int srlen, int tos)
{
int on=1;
net = socket(addr->ai_family, SOCK_STREAM, 0);
if (net < 0) {
if (errno == EAFNOSUPPORT || errno == EINVAL)
return 1;
perror("telnet: socket");
return 0;
}
#if defined(IP_OPTIONS) && defined(HAS_IPPROTO_IP)
if (srcroute) {
if (addr->ai_family != AF_INET)
fputs("Source route is only supported for IPv4\n", stderr);
if (setsockopt(net, IPPROTO_IP, IP_OPTIONS, srcroute, srlen) < 0)
perror("setsockopt (IP_OPTIONS)");
}
#endif
#if defined(HAS_IPPROTO_IP) && defined(IP_TOS)
#if defined(HAS_GETTOS)
struct tosent *tp;
if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
tos = tp->t_tos;
#endif
if (tos < 0) tos = 020; /* Low Delay bit */
if (tos && (setsockopt(net, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
&& (errno != ENOPROTOOPT) && (errno != EOPNOTSUPP))
perror("telnet: setsockopt (IP_TOS) (ignored)");
#endif /* defined(IPPROTO_IP) && defined(IP_TOS) */
if (debug && setsockopt(net, SOL_SOCKET, SO_DEBUG, &on, sizeof(on)) < 0) {
perror("setsockopt (SO_DEBUG)");
}
if (::connect(net, addr->ai_addr, addr->ai_addrlen) < 0) {
return 1;
}
return 2;
}
void netlink::oobinline() {
int on=1;
/* Systems without SO_OOBINLINE probably won't work */
if (setsockopt(net, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) == -1) {
perror("setsockopt");
}
}
/*
* Check to see if any out-of-band data exists on a socket (for
* Telnet "synch" processing).
*/
int netlink::stilloob(void) {
static struct timeval timeout = { 0, 0 };
fd_set excepts;
int value;
do {
FD_ZERO(&excepts);
FD_SET(net, &excepts);
value = select(net+1, NULL, NULL, &excepts, &timeout);
} while ((value == -1) && (errno == EINTR));
if (value < 0) {
perror("select");
quit();
/* NOTREACHED */
}
if (FD_ISSET(net, &excepts)) {
return 1;
} else {
return 0;
}
}
int netlink::send(const char *s, int n, int f) {
return ::send(net, s, n, f);
}
void netlink::nonblock(int onoff) {
ioctl(net, FIONBIO, &onoff);
}
int netlink::getfd() {
return net;
}
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