#include "toys.h" int xsocket(int domain, int type, int protocol) { int fd = socket(domain, type, protocol); if (fd < 0) perror_exit("socket %x %x", type, protocol); fcntl(fd, F_SETFD, FD_CLOEXEC); return fd; } void xsetsockopt(int fd, int level, int opt, void *val, socklen_t len) { if (-1 == setsockopt(fd, level, opt, val, len)) perror_exit("setsockopt"); } struct addrinfo *xgetaddrinfo(char *host, char *port, int family, int socktype, int protocol, int flags) { struct addrinfo info, *ai; int rc; memset(&info, 0, sizeof(struct addrinfo)); info.ai_family = family; info.ai_socktype = socktype; info.ai_protocol = protocol; info.ai_flags = flags; rc = getaddrinfo(host, port, &info, &ai); if (rc || !ai) error_exit("%s%s%s: %s", host, port ? ":" : "", port ? port : "", rc ? gai_strerror(rc) : "not found"); return ai; } int xconnect(struct addrinfo *ai_arg) { struct addrinfo *ai; int fd = -1; // Try all the returned addresses. Report errors if last entry can't connect. for (ai = ai_arg; ai; ai = ai->ai_next) { fd = (ai->ai_next ? socket : xsocket)(ai->ai_family, ai->ai_socktype, ai->ai_protocol); if (!connect(fd, ai->ai_addr, ai->ai_addrlen)) break; else if (!ai->ai_next) perror_exit("connect"); close(fd); } freeaddrinfo(ai_arg); return fd; } int xpoll(struct pollfd *fds, int nfds, int timeout) { int i; for (;;) { if (0>(i = poll(fds, nfds, timeout))) { if (toys.signal) return i; if (errno != EINTR && errno != ENOMEM) perror_exit("xpoll"); else if (timeout>0) timeout--; } else return i; } } // Loop forwarding data from in1 to out1 and in2 to out2, handling // half-connection shutdown. timeouts return if no data for X miliseconds. // Returns 0: both closed, 1 shutdown_timeout, 2 timeout int pollinate(int in1, int in2, int out1, int out2, int timeout, int shutdown_timeout) { struct pollfd pollfds[2]; int i, pollcount = 2; memset(pollfds, 0, 2*sizeof(struct pollfd)); pollfds[0].events = pollfds[1].events = POLLIN; pollfds[0].fd = in1; pollfds[1].fd = in2; // Poll loop copying data from each fd to the other one. for (;;) { if (!xpoll(pollfds, pollcount, timeout)) return pollcount; for (i=0; i<pollcount; i++) { if (pollfds[i].revents & POLLIN) { int len = read(pollfds[i].fd, libbuf, sizeof(libbuf)); if (len<1) pollfds[i].revents = POLLHUP; else xwrite(i ? out2 : out1, libbuf, len); } if (pollfds[i].revents & POLLHUP) { // Close half-connection. This is needed for things like // "echo GET / | netcat landley.net 80" // Note that in1 closing triggers timeout, in2 returns now. if (i) { shutdown(pollfds[0].fd, SHUT_WR); pollcount--; timeout = shutdown_timeout; } else return 0; } } } }