/*

	resolver.c: TCP network stuff, for IPv4 and IPv6

	Oh, and also some URL parsing... extracting host name and such.

	copyright 2008-2010 by the mpg123 project - free software under the terms of the LGPL 2.1

	see COPYING and AUTHORS files in distribution or http://mpg123.org

	initially written Thomas Orgis (based on httpget.c)

	The idea is to have everything involving the game between URLs and IPs/connections separated here.

	I begin with the outsourcing of IPv4 stuff, then make the stuff generic.

*/

/* Newer glibc is strict about this: getaddrinfo() stuff needs POSIX2K. */

#define _POSIX_C_SOURCE 200112L

#include "mpg123app.h"

#ifdef NETWORK

#include "true.h"

#include "resolver.h"

#if !defined (WANT_WIN32_SOCKETS)

#include <netdb.h>

#include <sys/param.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <errno.h>

#endif

#ifdef HAVE_SYS_SELECT_H

#include <sys/select.h>

#endif

#ifdef HAVE_SYS_TIME_H

#include <sys/time.h>

#endif

#ifdef HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif

#include <unistd.h>

#include "debug.h"

int split_url(mpg123_string *url, mpg123_string *auth, mpg123_string *host, mpg123_string *port, mpg123_string *path)

{

	size_t pos  = 0; /* current position in input URL */

	size_t pos2 = 0; /* another position in input URL */

#ifdef IPV6

	size_t pos3 = 0; /* yet another (for IPv6 port)   */

#endif

	char *part  = NULL; /* a part of url we work on */

	int ret = TRUE; /* return code */

	/* Zeroing the output strings; not freeing to avoid unnecessary mallocs. */

	if(auth) auth->fill = 0;

	if(host) host->fill = 0;

	if(port) port->fill = 0;

	if(path) path->fill = 0;

	if(!url || !url->fill || url->p[url->fill-1] != 0)

	{

		error("URL string is not good! (Programmer's fault!?)");

		return FALSE;

	}

	if (!(strncmp(url->p+pos, "http://", 7)))

	pos += 7; /* Drop protocol. */

	/* Extract user[:passwd]@... */

	if( (part = strchr(url->p+pos,'@')) )

	{

		size_t i;

		size_t partlen = part - url->p - pos;

		int have_auth = TRUE;

		/* User names or passwords don't have "/" in them (?), the "@" wasn't for real if we find such. */

		for(i=0;i

		{

			if(url->p[pos+i] == '/' )

			{

				have_auth = FALSE;

				break;

			}

		}

		if(have_auth)

		{

			if(auth != NULL && !mpg123_set_substring(auth, url->p, pos, partlen))

			{

				error("Cannot set auth string (out of mem?).");

				return FALSE;

			}

			pos += partlen+1; /* Continuing after the "@". */

		}

	}

	/* Extract host name or IP. */

#ifdef IPV6

	if(url->p[pos] == '[')

	{ /* It's possibly an IPv6 url in [ ] */

		++pos;

		if( (part = strchr(url->p+pos,']')) != NULL)

		{

			pos2 = part-url->p;

			pos3 = pos2+1; /* : after ] */

		}

		else { error("Malformed IPv6 URL!"); return FALSE; }

	}

	else

	{

#endif

	for(pos2=pos; pos2 < url->fill-1; ++pos2)

	{

		char a = url->p[pos2];

		if( a == ':' || a == '/') break;

	}

#ifdef IPV6

		pos3 = pos2;

	}

#endif

	/* At pos2 there is now either a delimiter or the end. */

debug4("hostname between %lu and %lu, %lu chars of %s", (unsigned long)pos, (unsigned long)pos2, (unsigned long)(pos2-pos), url->p + pos);

	if(host != NULL && !mpg123_set_substring(host, url->p, pos, pos2-pos))

	{

		error("Cannot set host string (out of mem?).");

		return FALSE;

	}

#ifdef IPV6

	pos = pos3; /* Look after ], if present. */

#else

	pos = pos2;

#endif

	/* Now for the port... */

	if(url->p[pos] == ':')

	{

		pos += 1; /* We begin _after_ the ":". */

		for(pos2=pos; pos2 < url->fill-1; ++pos2)

		if( url->p[pos2] == '/' ) break;

		/* Check for port being numbers? Not sure if that's needed. */

		if(port) ret = mpg123_set_substring(port, url->p, pos, pos2-pos);

		pos = pos2;

	}

	else if(port) ret = mpg123_set_string(port, "80");

	if(!ret)

	{

		error("Cannot set port string (out of mem?).");

		return FALSE;

	}

	/* Now only the path is left.

	   If there is no path at all, assume "/" */

	if(path) ret = url->p[pos] == 0

		? mpg123_set_string(path, "/")

		: mpg123_set_substring(path, url->p, pos, url->fill-1-pos);

	if(!ret) error("Cannot set path string (out of mem?)");

	return ret;

}

/* Switch between blocking and non-blocking mode. */

#if !defined (WANT_WIN32_SOCKETS)

static void nonblock(int sock)

{

	int flags = fcntl(sock, F_GETFL);

	flags |= O_NONBLOCK;

	fcntl(sock, F_SETFL, flags);

}

static void block(int sock)

{

	int flags = fcntl(sock, F_GETFL);

	flags &= ~O_NONBLOCK;

	fcntl(sock, F_SETFL, flags);

}

/* If we want a timeout, connect non-blocking and wait for that long... */

static int timeout_connect(int sockfd, const struct sockaddr *serv_addr, socklen_t addrlen)

{

	if(param.timeout > 0)

	{

		int err;

		nonblock(sockfd);

		err = connect(sockfd, serv_addr, addrlen);

		if(err == 0)

		{

			debug("immediately successful");

			block(sockfd);

			return 0;

		}

		else if(errno == EINPROGRESS)

		{

			struct timeval tv;

			fd_set fds;

			tv.tv_sec = param.timeout;

			tv.tv_usec = 0;

			debug("in progress, waiting...");

			FD_ZERO(&fds);

			FD_SET(sockfd, &fds);

			err = select(sockfd+1, NULL, &fds, NULL, &tv;;

			if(err > 0)

			{

				socklen_t len = sizeof(err);

				if(   (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &err, &len) == 0)

				   && (err == 0) )

				{

					debug("non-blocking connect has been successful");

					block(sockfd);

					return 0;

				}

				else

				{

					error1("connection error: %s", strerror(err));

					return -1;

				}

			}

			else if(err == 0)

			{

				error("connection timed out");

				return -1;

			}

			else

			{

				error1("error from select(): %s", strerror(errno));

				return -1;

			}

		}

		else

		{

			error1("connection failed: %s", strerror(errno));

			return err;

		}

	}

	else

	{

		if(connect(sockfd, serv_addr, addrlen))

		{

			error1("connection failed: %s", strerror(errno));

			return -1;

		}

		else return 0; /* _good_ */

	}

}

/* So, this then is the only routine that should know about IPv4 or v6 in future. */

int open_connection(mpg123_string *host, mpg123_string *port)

{

#ifndef IPV6 /* The legacy code for IPv4. No real change to keep all compatibility. */

#ifndef INADDR_NONE

#define INADDR_NONE 0xffffffff

#endif

	struct sockaddr_in server;

	struct hostent *myhostent;

	struct in_addr myaddr;

	int isip = 1;

	char *cptr = host->p;

	int sock = -1;

	if(param.verbose>1) fprintf(stderr, "Note: Attempting old-style connection to %s\n", host->p);

	/* Resolve to IP; parse port number. */

	while(*cptr) /* Iterate over characters of hostname, check if it's an IP or name. */

	{

		if ((*cptr < '0' || *cptr > '9') && *cptr != '.')

		{

			isip = 0;

			break;

		}

		cptr++;

	}

	if(!isip)

	{ /* Name lookup. */

		if (!(myhostent = gethostbyname(host->p))) return -1;

		memcpy (&myaddr, myhostent->h_addr, sizeof(myaddr));

		server.sin_addr.s_addr = myaddr.s_addr;

	}

	else  /* Just use the IP. */

	if((server.sin_addr.s_addr = inet_addr(host->p)) == INADDR_NONE)

	return -1;

	server.sin_port = htons(atoi(port->p));

	server.sin_family = AF_INET;

	if((sock = socket(PF_INET, SOCK_STREAM, 6)) < 0)

	{

		error1("Cannot create socket: %s", strerror(errno));

		return -1;

	}

	if(timeout_connect(sock, (struct sockaddr *)&server, sizeof(server)))

	return -1;

#else /* Host lookup and connection in a protocol independent manner. */

	struct addrinfo hints;

	struct addrinfo *addr, *addrlist;

	int ret, sock = -1;

	if(param.verbose>1) fprintf(stderr, "Note: Attempting new-style connection to %s\n", host->p);

	memset(&hints, 0, sizeof(struct addrinfo));

	hints.ai_family   = AF_UNSPEC; /* We accept both IPv4 and IPv6 ... and perhaps IPv8;-) */

	hints.ai_socktype = SOCK_STREAM;

	hints.ai_flags = 0;

#ifdef HAVE_GAI_ADDRCONFIG

	hints.ai_flags |= AI_ADDRCONFIG; /* Only ask for addresses that we have configured interfaces for. */

#endif

	ret = getaddrinfo(host->p, port->p, &hints, &addrlist);

	if(ret != 0)

	{

		error3("Resolving %s:%s: %s", host->p, port->p, gai_strerror(ret));

		return -1;

	}

	addr = addrlist;

	while(addr != NULL)

	{

		sock = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);

		if(sock >= 0)

		{

			if(timeout_connect(sock, addr->ai_addr, addr->ai_addrlen) == 0)

			break;

			close(sock);

			sock=-1;

		}

		addr=addr->ai_next;

	}

	if(sock < 0) error2("Cannot resolve/connect to %s:%s!", host->p, port->p);

	freeaddrinfo(addrlist);

#endif

	return sock; /* Hopefully, that's an open socket to talk with. */

}

#endif /* !defined (WANT_WIN32_SOCKETS) */

#else /* NETWORK */

void resolver_dummy_without_sense()

{

	/* Some compilers don't like empty source files. */

}

#endif