httcp.c

用于linux和其他unix下面的

/*			Generic Communication Code		HTTCP.c
**			==========================
**
**	This code is in common between client and server sides.
**
**	16 Jan 92  TBL	Fix strtol() undefined on CMU Mach.
**	25 Jun 92  JFG	Added DECNET option through TCP socket emulation.
**	13 Sep 93  MD	Added correct return of vmserrorno for HTInetStatus.
**			Added decoding of vms error message for MULTINET.
**	7-DEC-1993 Bjorn S. Nilsson, ALEPH, CERN, VMS UCX ioctl() changes
**			(done of Mosaic)
**	19 Feb 94  Danny Mayer	Added Bjorn Fixes to Lynx version
**	 7 Mar 94  Danny Mayer	Added Fix UCX version for full domain name
**	20 May 94  Andy Harper	Added support for CMU TCP/IP transport
**	17 Nov 94  Andy Harper	Added support for SOCKETSHR transport
**	16 Jul 95  S. Bjorndahl added kluge to deal with LIBCMU bug
*/

#include <HTUtils.h>
#include <HTParse.h>
#include <HTAlert.h>
#include <HTTCP.h>
#include <LYGlobalDefs.h>	/* added for no_suspend */
#include <LYUtils.h>

#ifdef NSL_FORK
#include <signal.h>
#include <www_wait.h>
#endif /* NSL_FORK */

#ifdef HAVE_RESOLV_H
#include <resolv.h>
#endif

#ifdef __DJGPP__
#include <netdb.h>
#endif /* __DJGPP__ */

#define OK_HOST(p) ((p) != 0 && ((p)->h_length) != 0)

#ifdef SVR4_BSDSELECT
PUBLIC int BSDselect PARAMS((
	int		 nfds,
	fd_set *	 readfds,
	fd_set *	 writefds,
	fd_set *	 exceptfds,
	struct timeval * select_timeout));
#ifdef select
#undef select
#endif /* select */
#define select BSDselect
#ifdef SOCKS
#ifdef Rselect
#undef Rselect
#endif /* Rselect */
#define Rselect BSDselect
#endif /* SOCKS */
#endif /* SVR4_BSDSELECT */

#include <LYLeaks.h>

#ifndef FD_SETSIZE
#if defined(UCX) || defined(SOCKETSHR_TCP) || defined(CMU_TCP)
#define FD_SETSIZE 32
#else
#define FD_SETSIZE 256
#endif /* Limit # sockets to 32 for UCX, BSN - also SOCKETSHR and CMU, AH */
#endif /* FD_SETSIZE */

/*
**  Module-Wide variables
*/
PRIVATE char *hostname = NULL;		/* The name of this host */

/*
**  PUBLIC VARIABLES
*/
#ifdef SOCKS
extern BOOLEAN socks_flag;
PUBLIC unsigned long socks_bind_remoteAddr; /* for long Rbind */
#endif /* SOCKS */

/* PUBLIC SockA HTHostAddress; */	/* The internet address of the host */
					/* Valid after call to HTHostName() */

/*	Encode INET status (as in sys/errno.h)			  inet_status()
**	------------------
**
**  On entry,
**	where		gives a description of what caused the error
**	global errno	gives the error number in the Unix way.
**
**  On return,
**	returns		a negative status in the Unix way.
*/

#ifdef DECL_SYS_ERRLIST
extern char *sys_errlist[];		/* see man perror on cernvax */
extern int sys_nerr;
#endif /* DECL_SYS_ERRLIST */

#ifdef _WINDOWS_NSL
char host[512];
struct hostent  *phost;	/* Pointer to host - See netdb.h */
int donelookup;

static unsigned long _fork_func (void *arglist)
{
#ifdef SH_EX
    unsigned long addr;
    addr = (unsigned long)inet_addr(host);
    if ((int)addr != -1)
	phost = gethostbyaddr((char *)&addr, sizeof (addr), AF_INET);
    else
	phost = gethostbyname(host);
#else
    phost = gethostbyname(host);
#endif
    donelookup = TRUE;
    return (unsigned long)(phost);
}
#endif /* _WINDOWS_NSL */

#if defined(VMS) && defined(UCX)
/*
**  A routine to mimic the ioctl function for UCX.
**  Bjorn S. Nilsson, 25-Nov-1993. Based on an example in the UCX manual.
*/
#include <HTioctl.h>

PUBLIC int HTioctl ARGS3(
	int,		d,
	int,		request,
	int *,		argp)
{
    int sdc, status;
    unsigned short fun, iosb[4];
    char *p5, *p6;
    struct comm {
	int command;
	char *addr;
    } ioctl_comm;
    struct it2 {
	unsigned short len;
	unsigned short opt;
	struct comm *addr;
    } ioctl_desc;

    if ((sdc = vaxc$get_sdc (d)) == 0) {
	set_errno(EBADF);
	return -1;
    }
    ioctl_desc.opt  = UCX$C_IOCTL;
    ioctl_desc.len  = sizeof(struct comm);
    ioctl_desc.addr = &ioctl_comm;
    if (request & IOC_OUT) {
	fun = IO$_SENSEMODE;
	p5 = 0;
	p6 = (char *)&ioctl_desc;
    } else {
	fun = IO$_SETMODE;
	p5 = (char *)&ioctl_desc;
	p6 = 0;
    }
    ioctl_comm.command = request;
    ioctl_comm.addr = (char *)argp;
    status = sys$qiow (0, sdc, fun, iosb, 0, 0, 0, 0, 0, 0, p5, p6);
    if (!(status & 01)) {
	set_errno(status);
	return -1;
    }
    if (!(iosb[0] & 01)) {
	set_errno(iosb[0]);
	return -1;
    }
    return 0;
}
#endif /* VMS && UCX */

#define MY_FORMAT "TCP: Error %d in `SOCKET_ERRNO' after call to %s() failed.\n\t%s\n"
	   /* third arg is transport/platform specific */

/*	Report Internet Error
**	---------------------
*/
PUBLIC int HTInetStatus ARGS1(
	char *,		where)
{
    int status;
    int saved_errno = errno;
#ifdef VMS
#ifdef MULTINET
    SOCKET_ERRNO = vmserrno;
#endif /* MULTINET */
#endif /* VMS */

#ifdef VM
    CTRACE((tfp, MY_FORMAT, SOCKET_ERRNO,  where,
	   "(Error number not translated)"));	/* What Is the VM equiv? */
#define ER_NO_TRANS_DONE
#endif /* VM */

#ifdef VMS
#ifdef MULTINET
    CTRACE((tfp, MY_FORMAT, SOCKET_ERRNO,  where,
	   vms_errno_string()));
#else
    CTRACE((tfp, MY_FORMAT, SOCKET_ERRNO,  where,
	   ((SOCKET_ERRNO > 0 && SOCKET_ERRNO <= 65) ?
	    strerror(SOCKET_ERRNO) : "(Error number not translated)")));
#endif /* MULTINET */
#define ER_NO_TRANS_DONE
#endif /* VMS */

#ifdef HAVE_STRERROR
    CTRACE((tfp, MY_FORMAT, SOCKET_ERRNO,  where,
	   strerror(SOCKET_ERRNO)));
#define ER_NO_TRANS_DONE
#endif /* HAVE_STRERROR */

#ifndef ER_NO_TRANS_DONE
    CTRACE((tfp, MY_FORMAT, SOCKET_ERRNO,  where,
	   (SOCKET_ERRNO < sys_nerr ?
	    sys_errlist[SOCKET_ERRNO] : "Unknown error" )));
#endif /* !ER_NO_TRANS_DONE */

#ifdef VMS
#ifndef MULTINET
    CTRACE((tfp,
	   "         Unix error number (SOCKET_ERRNO) = %ld dec\n",
	   SOCKET_ERRNO));
    CTRACE((tfp,
	   "         VMS error (vaxc$errno)    = %lx hex\n",
	   vaxc$errno));
#endif /* MULTINET */
#endif /* VMS */

    set_errno(saved_errno);

#ifdef VMS
    /*
    **	uerrno and errno happen to be zero if vmserrno <> 0
    */
#ifdef MULTINET
    status = -vmserrno;
#else
    status = -vaxc$errno;
#endif /* MULTINET */
#else
    status = -SOCKET_ERRNO;
#endif /* VMS */
    return status;
}

/*	Parse a cardinal value				       parse_cardinal()
**	----------------------
**
** On entry,
**	*pp	    points to first character to be interpreted, terminated by
**		    non 0:9 character.
**	*pstatus    points to status already valid
**	maxvalue    gives the largest allowable value.
**
** On exit,
**	*pp	    points to first unread character
**	*pstatus    points to status updated iff bad
*/
PUBLIC unsigned int HTCardinal ARGS3(
	int *,		pstatus,
	char **,	pp,
	unsigned int,	max_value)
{
    unsigned int n;
    if ((**pp<'0') || (**pp>'9')) {	    /* Null string is error */
	*pstatus = -3;	/* No number where one expected */
	return 0;
    }

    n = 0;
    while ((**pp >= '0') && (**pp <= '9'))
	n = n*10 + *((*pp)++) - '0';

    if (n > max_value) {
	*pstatus = -4;	/* Cardinal outside range */
	return 0;
    }

    return n;
}

#ifndef DECNET	/* Function only used below for a trace message */
/*	Produce a string for an Internet address
**	----------------------------------------
**
**  On exit,
**	returns a pointer to a static string which must be copied if
**		it is to be kept.
*/
PUBLIC CONST char * HTInetString ARGS1(
	SockA*,		soc_in)
{
#ifdef INET6
    static char hostbuf[MAXHOSTNAMELEN];
    getnameinfo((struct sockaddr *)soc_in,
	    SOCKADDR_LEN(soc_in),
	    hostbuf, sizeof(hostbuf), NULL, 0, NI_NUMERICHOST);
    return hostbuf;
#else
    static char string[20];
    sprintf(string, "%d.%d.%d.%d",
	    (int)*((unsigned char *)(&soc_in->sin_addr)+0),
	    (int)*((unsigned char *)(&soc_in->sin_addr)+1),
	    (int)*((unsigned char *)(&soc_in->sin_addr)+2),
	    (int)*((unsigned char *)(&soc_in->sin_addr)+3));
    return string;
#endif /* INET6 */
}
#endif /* !DECNET */

/*	Check whether string is a valid Internet hostname - kw
**	-------------------------------------------------
**
**  Checks whether
**  - contains only valid chars for domain names (actually, the
**    restrictions are somewhat relaxed),
**  - no leading dots or empty segments,
**  - no segment starts with '-' or '+' [this protects telnet command],
**  - max. length of dot-separated segment <= 63 (RFC 1034,1035),
**  - total length <= 254 (if it ends with dot) or 253 (otherwise)
**     [an interpretation of RFC 1034,1035, although RFC 1123
**      suggests 255 as limit - kw].
**
**  Note: user (before '@') and port (after ':') components from
**      host part of URL should be already stripped (if appropriate)
**      from the input string.
**
**  On exit,
**	returns 1 if valid, otherwise 0.
*/
PUBLIC BOOL valid_hostname ARGS1(
	char *,	name)
{
    int i=1, iseg = 0;
    char *cp = name;
    if (!(name && *name))
	return NO;
    for (; (*cp && i <= 253); cp++, i++) {
	if (*cp == '.') {
	    if (iseg == 0) {
		return NO;
	    } else {
		iseg = 0;
		continue;
	    }
	} else if (iseg == 0 && (*cp == '-' || *cp == '+')) {
	    return NO;
	} else if (++iseg > 63) {
	    return NO;
	}
	if (!isalnum(UCH(*cp)) &&
	    *cp != '-' && *cp != '_' &&
	    *cp != '$' && *cp != '+') {
	    return NO;
	}
    }
    return (BOOL) (*cp == '\0' || (*cp == '.' && iseg != 0 && cp[1] == '\0'));
}

#ifdef NSL_FORK
/*
**  Function to allow us to be killed with a normal signal (not
**  SIGKILL), but don't go through normal libc exit() processing, which
**  would screw up parent's stdio.  -BL
*/
PRIVATE void quench ARGS1(
	int,	sig GCC_UNUSED)
{
    _exit(2);
}
#endif /* NSL_FORK */

PUBLIC int lynx_nsl_status = HT_OK;

#define DEBUG_HOSTENT		/* disable in case of problems */
#define DEBUG_HOSTENT_CHILD  /* for NSL_FORK, may screw up trace file */

/*
**  Two auxiliary functions for name lookup and struct hostent.
**
**  dump_hostent - dumps the contents of a struct hostent to the
**  trace log or stderr, including all pointer values, strings, and
**  addresses, in a format inspired by gdb's print format. - kw
*/
PRIVATE void dump_hostent ARGS2(
    CONST char *,		msgprefix,
    CONST struct hostent *,	phost)
{
    if (TRACE) {
	int i;
	char **pcnt;
	CTRACE((tfp,"%s: %p ", msgprefix, phost));
	if (phost) {
	    CTRACE((tfp,"{ h_name = %p", phost->h_name));
	    if (phost->h_name) {
		CTRACE((tfp, " \"%s\",", phost->h_name));
	    } else {
		CTRACE((tfp, ","));
	    }
	    CTRACE((tfp,"\n\t h_aliases = %p", phost->h_aliases));
	    if (phost->h_aliases) {
		CTRACE((tfp, " {"));
		for (pcnt = phost->h_aliases; *pcnt; pcnt++) {
		    CTRACE((tfp,"%s %p \"%s\"",
			   (pcnt == phost->h_aliases ? " " : ", "),
			   *pcnt, *pcnt));
		}
		CTRACE((tfp, "%s0x0 },\n\t",
		       (*phost->h_aliases ? ", " : " ")));
	    } else {
		CTRACE((tfp, ",\n\t"));
	    }
	    CTRACE((tfp," h_addrtype = %d,", phost->h_addrtype));
	    CTRACE((tfp," h_length = %d,\n\t", phost->h_length));
	    CTRACE((tfp," h_addr_list = %p", phost->h_addr_list));
	    if (phost->h_addr_list) {
		CTRACE((tfp, " {"));
		for (pcnt = phost->h_addr_list; *pcnt; pcnt++) {
		    CTRACE((tfp,"%s %p",
			   (pcnt == phost->h_addr_list ? "" : ","),
			   *pcnt));
		    for (i = 0; i < phost->h_length; i++) {
			CTRACE((tfp, "%s%d%s", (i==0 ? " \"" : "."),
			       (int)*((unsigned char *)(*pcnt)+i),
			       (i+1 == phost->h_length ? "\"" : "")));
		    }
		}
		if (*phost->h_addr_list) {
		    CTRACE((tfp, ", 0x0 } }"));
		} else {
		    CTRACE((tfp, " 0x0 } }"));
		}
	    } else {
		CTRACE((tfp, "}"));
	    }
	}
	CTRACE((tfp,"\n"));
	fflush(tfp);
    }
}

/*
**  fill_rehostent - copies as much as possible relevant content from
**  the struct hostent pointed to by phost to the char buffer given
**  by rehostent, subject to maximum output length rehostentsize,
**  following pointers and building self-contained output which can be
**  cast to a struct hostent. - kw
**  See also description of LYGetHostByName.
*/
#ifdef NSL_FORK

#define REHOSTENT_SIZE 128		/* not bigger than pipe buffer! */

typedef struct {
	struct hostent	h;
	char		rest[REHOSTENT_SIZE];
    } AlignedHOSTENT;

PRIVATE size_t fill_rehostent ARGS3(
    char *,			rehostent,
    size_t,			rehostentsize,
    CONST struct hostent *,	phost)
{
    AlignedHOSTENT *data = (AlignedHOSTENT *)rehostent;
    int num_addrs = 0;
    int num_aliases = 0;
    char **pcnt;
    char *p_next_char;
    char **p_next_charptr;
    size_t name_len = 0;
    size_t required_per_addr;
    size_t curlen = sizeof(struct hostent);
    size_t available = rehostentsize - curlen;
    size_t chk_available, mem_this_alias, required_this_alias;
    int i_addr, i_alias;

    if (!phost)
	return 0;
    required_per_addr = phost->h_length + sizeof(char *);
    if (phost->h_addr_list)
	available -= sizeof(phost->h_addr_list[0]);
    if (phost->h_aliases)
	available -= sizeof(phost->h_aliases[0]);
    if (phost->h_name)
	available--;
    if (phost->h_addr_list) {
	if (phost->h_addr_list[0]) {
	    if (available >= required_per_addr) {
		num_addrs++;
		available -= required_per_addr;
	    }
	}
    }
    if (phost->h_name) {
	name_len = strlen(phost->h_name);
	if (available >= name_len) {
	    available -= name_len;
	} else {
	    name_len = 0;
	}
    }
    if (num_addrs) {
	for (pcnt=phost->h_addr_list+1; *pcnt; pcnt++) {
	    if (available >= required_per_addr) {
		num_addrs++;
		available -= required_per_addr;
	    } else {
		break;
	    }
	}
    }
    chk_available = available;
    if (phost->h_aliases) {
	for (pcnt=phost->h_aliases; *pcnt; pcnt++) {
	    required_this_alias = sizeof(phost->h_aliases[0]) +
		strlen(*pcnt) + 1;
	    if (chk_available >= required_this_alias) {
		num_aliases++;
		chk_available -= required_this_alias;
	    }
	}
    }