1 #include "toys.h"
2 
xsocket(int domain,int type,int protocol)3 int xsocket(int domain, int type, int protocol)
4 {
5   int fd = socket(domain, type, protocol);
6 
7   if (fd < 0) perror_exit("socket %x %x", type, protocol);
8   fcntl(fd, F_SETFD, FD_CLOEXEC);
9 
10   return fd;
11 }
12 
xsetsockopt(int fd,int level,int opt,void * val,socklen_t len)13 void xsetsockopt(int fd, int level, int opt, void *val, socklen_t len)
14 {
15   if (-1 == setsockopt(fd, level, opt, val, len)) perror_exit("setsockopt");
16 }
17 
xconnect(char * host,char * port,int family,int socktype,int protocol,int flags)18 int xconnect(char *host, char *port, int family, int socktype, int protocol,
19              int flags)
20 {
21   struct addrinfo info, *ai, *ai2;
22   int fd;
23 
24   memset(&info, 0, sizeof(struct addrinfo));
25   info.ai_family = family;
26   info.ai_socktype = socktype;
27   info.ai_protocol = protocol;
28   info.ai_flags = flags;
29 
30   fd = getaddrinfo(host, port, &info, &ai);
31   if (fd || !ai)
32     error_exit("Connect '%s%s%s': %s", host, port ? ":" : "", port ? port : "",
33       fd ? gai_strerror(fd) : "not found");
34 
35   // Try all the returned addresses. Report errors if last entry can't connect.
36   for (ai2 = ai; ai; ai = ai->ai_next) {
37     fd = (ai->ai_next ? socket : xsocket)(ai->ai_family, ai->ai_socktype,
38       ai->ai_protocol);
39     if (!connect(fd, ai->ai_addr, ai->ai_addrlen)) break;
40     else if (!ai->ai_next) perror_exit("connect");
41     close(fd);
42   }
43   freeaddrinfo(ai2);
44 
45   return fd;
46 }
47 
xpoll(struct pollfd * fds,int nfds,int timeout)48 int xpoll(struct pollfd *fds, int nfds, int timeout)
49 {
50   int i;
51 
52   for (;;) {
53     if (0>(i = poll(fds, nfds, timeout))) {
54       if (toys.signal) return i;
55       if (errno != EINTR && errno != ENOMEM) perror_exit("xpoll");
56       else if (timeout>0) timeout--;
57     } else return i;
58   }
59 }
60 
61 // Loop forwarding data from in1 to out1 and in2 to out2, handling
62 // half-connection shutdown. timeouts return if no data for X miliseconds.
63 // Returns 0: both closed, 1 shutdown_timeout, 2 timeout
pollinate(int in1,int in2,int out1,int out2,int timeout,int shutdown_timeout)64 int pollinate(int in1, int in2, int out1, int out2, int timeout, int shutdown_timeout)
65 {
66   struct pollfd pollfds[2];
67   int i, pollcount = 2;
68 
69   memset(pollfds, 0, 2*sizeof(struct pollfd));
70   pollfds[0].events = pollfds[1].events = POLLIN;
71   pollfds[0].fd = in1;
72   pollfds[1].fd = in2;
73 
74   // Poll loop copying data from each fd to the other one.
75   for (;;) {
76     if (!xpoll(pollfds, pollcount, timeout)) return pollcount;
77 
78     for (i=0; i<pollcount; i++) {
79       if (pollfds[i].revents & POLLIN) {
80         int len = read(pollfds[i].fd, libbuf, sizeof(libbuf));
81         if (len<1) pollfds[i].revents = POLLHUP;
82         else xwrite(i ? out2 : out1, libbuf, len);
83       }
84       if (pollfds[i].revents & POLLHUP) {
85         // Close half-connection.  This is needed for things like
86         // "echo GET / | netcat landley.net 80"
87         // Note that in1 closing triggers timeout, in2 returns now.
88         if (i) {
89           shutdown(pollfds[0].fd, SHUT_WR);
90           pollcount--;
91           timeout = shutdown_timeout;
92         } else return 0;
93       }
94     }
95   }
96 }
97