lib/libc/net/ip6opt.c: Add from FreeBSD

1 files changed, 593 insertions, 0 deletions

diff --git a/freebsd/lib/libc/net/ip6opt.c b/freebsd/lib/libc/net/ip6opt.c
new file mode 100644
index 00000000..b3fe4a08
--- /dev/null
+++ b/freebsd/lib/libc/net/ip6opt.c
@@ -0,0 +1,593 @@
+/*	$KAME: ip6opt.c,v 1.13 2003/06/06 10:08:20 suz Exp $	*/
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/sys/param.h>
+#include <rtems/bsd/sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <netinet/ip6.h>
+
+#include <string.h>
+#include <stdio.h>
+
+static int ip6optlen(u_int8_t *opt, u_int8_t *lim);
+static void inet6_insert_padopt(u_char *p, int len);
+
+/*
+ * This function returns the number of bytes required to hold an option
+ * when it is stored as ancillary data, including the cmsghdr structure
+ * at the beginning, and any padding at the end (to make its size a
+ * multiple of 8 bytes).  The argument is the size of the structure
+ * defining the option, which must include any pad bytes at the
+ * beginning (the value y in the alignment term "xn + y"), the type
+ * byte, the length byte, and the option data.
+ */
+int
+inet6_option_space(int nbytes)
+{
+	nbytes += 2;	/* we need space for nxt-hdr and length fields */
+	return(CMSG_SPACE((nbytes + 7) & ~7));
+}
+
+/*
+ * This function is called once per ancillary data object that will
+ * contain either Hop-by-Hop or Destination options.  It returns 0 on
+ * success or -1 on an error.
+ */
+int
+inet6_option_init(void *bp, struct cmsghdr **cmsgp, int type)
+{
+	struct cmsghdr *ch = (struct cmsghdr *)bp;
+
+	/* argument validation */
+	if (type != IPV6_HOPOPTS && type != IPV6_DSTOPTS)
+		return(-1);
+	
+	ch->cmsg_level = IPPROTO_IPV6;
+	ch->cmsg_type = type;
+	ch->cmsg_len = CMSG_LEN(0);
+
+	*cmsgp = ch;
+	return(0);
+}
+
+/*
+ * This function appends a Hop-by-Hop option or a Destination option
+ * into an ancillary data object that has been initialized by
+ * inet6_option_init().  This function returns 0 if it succeeds or -1 on
+ * an error.
+ * multx is the value x in the alignment term "xn + y" described
+ * earlier.  It must have a value of 1, 2, 4, or 8.
+ * plusy is the value y in the alignment term "xn + y" described
+ * earlier.  It must have a value between 0 and 7, inclusive.
+ */
+int
+inet6_option_append(struct cmsghdr *cmsg, const u_int8_t *typep, int multx,
+    int plusy)
+{
+	int padlen, optlen, off;
+	u_char *bp = (u_char *)cmsg + cmsg->cmsg_len;
+	struct ip6_ext *eh = (struct ip6_ext *)CMSG_DATA(cmsg);
+
+	/* argument validation */
+	if (multx != 1 && multx != 2 && multx != 4 && multx != 8)
+		return(-1);
+	if (plusy < 0 || plusy > 7)
+		return(-1);
+
+	/*
+	 * If this is the first option, allocate space for the
+	 * first 2 bytes(for next header and length fields) of
+	 * the option header.
+	 */
+	if (bp == (u_char *)eh) {
+		bp += 2;
+		cmsg->cmsg_len += 2;
+	}
+
+	/* calculate pad length before the option. */
+	off = bp - (u_char *)eh;
+	padlen = (((off % multx) + (multx - 1)) & ~(multx - 1)) -
+		(off % multx);
+	padlen += plusy;
+	padlen %= multx;	/* keep the pad as short as possible */
+	/* insert padding */
+	inet6_insert_padopt(bp, padlen);
+	cmsg->cmsg_len += padlen;
+	bp += padlen;
+
+	/* copy the option */
+	if (typep[0] == IP6OPT_PAD1)
+		optlen = 1;
+	else
+		optlen = typep[1] + 2;
+	memcpy(bp, typep, optlen);
+	bp += optlen;
+	cmsg->cmsg_len += optlen;
+
+	/* calculate pad length after the option and insert the padding */
+	off = bp - (u_char *)eh;
+	padlen = ((off + 7) & ~7) - off;
+	inet6_insert_padopt(bp, padlen);
+	bp += padlen;
+	cmsg->cmsg_len += padlen;
+
+	/* update the length field of the ip6 option header */
+	eh->ip6e_len = ((bp - (u_char *)eh) >> 3) - 1;
+
+	return(0);
+}
+
+/*
+ * This function appends a Hop-by-Hop option or a Destination option
+ * into an ancillary data object that has been initialized by
+ * inet6_option_init().  This function returns a pointer to the 8-bit
+ * option type field that starts the option on success, or NULL on an
+ * error.
+ * The difference between this function and inet6_option_append() is
+ * that the latter copies the contents of a previously built option into
+ * the ancillary data object while the current function returns a
+ * pointer to the space in the data object where the option's TLV must
+ * then be built by the caller.
+ * 
+ */
+u_int8_t *
+inet6_option_alloc(struct cmsghdr *cmsg, int datalen, int multx, int plusy)
+{
+	int padlen, off;
+	u_int8_t *bp = (u_char *)cmsg + cmsg->cmsg_len;
+	u_int8_t *retval;
+	struct ip6_ext *eh = (struct ip6_ext *)CMSG_DATA(cmsg);
+
+	/* argument validation */
+	if (multx != 1 && multx != 2 && multx != 4 && multx != 8)
+		return(NULL);
+	if (plusy < 0 || plusy > 7)
+		return(NULL);
+
+	/*
+	 * If this is the first option, allocate space for the
+	 * first 2 bytes(for next header and length fields) of
+	 * the option header.
+	 */
+	if (bp == (u_char *)eh) {
+		bp += 2;
+		cmsg->cmsg_len += 2;
+	}
+
+	/* calculate pad length before the option. */
+	off = bp - (u_char *)eh;
+	padlen = (((off % multx) + (multx - 1)) & ~(multx - 1)) -
+		(off % multx);
+	padlen += plusy;
+	padlen %= multx;	/* keep the pad as short as possible */
+	/* insert padding */
+	inet6_insert_padopt(bp, padlen);
+	cmsg->cmsg_len += padlen;
+	bp += padlen;
+
+	/* keep space to store specified length of data */
+	retval = bp;
+	bp += datalen;
+	cmsg->cmsg_len += datalen;
+
+	/* calculate pad length after the option and insert the padding */
+	off = bp - (u_char *)eh;
+	padlen = ((off + 7) & ~7) - off;
+	inet6_insert_padopt(bp, padlen);
+	bp += padlen;
+	cmsg->cmsg_len += padlen;
+
+	/* update the length field of the ip6 option header */
+	eh->ip6e_len = ((bp - (u_char *)eh) >> 3) - 1;
+
+	return(retval);
+}
+
+/*
+ * This function processes the next Hop-by-Hop option or Destination
+ * option in an ancillary data object.  If another option remains to be
+ * processed, the return value of the function is 0 and *tptrp points to
+ * the 8-bit option type field (which is followed by the 8-bit option
+ * data length, followed by the option data).  If no more options remain
+ * to be processed, the return value is -1 and *tptrp is NULL.  If an
+ * error occurs, the return value is -1 and *tptrp is not NULL.
+ * (RFC 2292, 6.3.5)
+ */
+int
+inet6_option_next(const struct cmsghdr *cmsg, u_int8_t **tptrp)
+{
+	struct ip6_ext *ip6e;
+	int hdrlen, optlen;
+	u_int8_t *lim;
+
+	if (cmsg->cmsg_level != IPPROTO_IPV6 ||
+	    (cmsg->cmsg_type != IPV6_HOPOPTS &&
+	     cmsg->cmsg_type != IPV6_DSTOPTS))
+		return(-1);
+
+	/* message length validation */
+	if (cmsg->cmsg_len < CMSG_SPACE(sizeof(struct ip6_ext)))
+		return(-1);
+	ip6e = (struct ip6_ext *)CMSG_DATA(cmsg);
+	hdrlen = (ip6e->ip6e_len + 1) << 3;
+	if (cmsg->cmsg_len < CMSG_SPACE(hdrlen))
+		return(-1);
+
+	/*
+	 * If the caller does not specify the starting point,
+	 * simply return the 1st option.
+	 * Otherwise, search the option list for the next option.
+	 */
+	lim = (u_int8_t *)ip6e + hdrlen;
+	if (*tptrp == NULL)
+		*tptrp = (u_int8_t *)(ip6e + 1);
+	else {
+		if ((optlen = ip6optlen(*tptrp, lim)) == 0)
+			return(-1);
+
+		*tptrp = *tptrp + optlen;
+	}
+	if (*tptrp >= lim) {	/* there is no option */
+		*tptrp = NULL;
+		return(-1);
+	}
+	/*
+	 * Finally, checks if the next option is safely stored in the
+	 * cmsg data.
+	 */
+	if (ip6optlen(*tptrp, lim) == 0)
+		return(-1);
+	else
+		return(0);
+}
+
+/*
+ * This function is similar to the inet6_option_next() function,
+ * except this function lets the caller specify the option type to be
+ * searched for, instead of always returning the next option in the
+ * ancillary data object.
+ * Note: RFC 2292 says the type of tptrp is u_int8_t *, but we think
+ *       it's a typo. The variable should be type of u_int8_t **.
+ */
+int
+inet6_option_find(const struct cmsghdr *cmsg, u_int8_t **tptrp, int type)
+{
+	struct ip6_ext *ip6e;
+	int hdrlen, optlen;
+	u_int8_t *optp, *lim;
+
+	if (cmsg->cmsg_level != IPPROTO_IPV6 ||
+	    (cmsg->cmsg_type != IPV6_HOPOPTS &&
+	     cmsg->cmsg_type != IPV6_DSTOPTS))
+		return(-1);
+
+	/* message length validation */
+	if (cmsg->cmsg_len < CMSG_SPACE(sizeof(struct ip6_ext)))
+		return(-1);
+	ip6e = (struct ip6_ext *)CMSG_DATA(cmsg);
+	hdrlen = (ip6e->ip6e_len + 1) << 3;
+	if (cmsg->cmsg_len < CMSG_SPACE(hdrlen))
+		return(-1);	
+
+	/*
+	 * If the caller does not specify the starting point,
+	 * search from the beginning of the option list.
+	 * Otherwise, search from *the next option* of the specified point.
+	 */
+	lim = (u_int8_t *)ip6e + hdrlen;
+	if (*tptrp == NULL)
+		*tptrp = (u_int8_t *)(ip6e + 1);
+	else {
+		if ((optlen = ip6optlen(*tptrp, lim)) == 0)
+			return(-1);
+
+		*tptrp = *tptrp + optlen;
+	}
+	for (optp = *tptrp; optp < lim; optp += optlen) {
+		if (*optp == type) {
+			*tptrp = optp;
+			return(0);
+		}
+		if ((optlen = ip6optlen(optp, lim)) == 0)
+			return(-1);
+	}
+
+	/* search failed */
+	*tptrp = NULL;
+	return(-1);
+}
+
+/*
+ * Calculate the length of a given IPv6 option. Also checks
+ * if the option is safely stored in user's buffer according to the
+ * calculated length and the limitation of the buffer.
+ */
+static int
+ip6optlen(u_int8_t *opt, u_int8_t *lim)
+{
+	int optlen;
+
+	if (*opt == IP6OPT_PAD1)
+		optlen = 1;
+	else {
+		/* is there enough space to store type and len? */
+		if (opt + 2 > lim)
+			return(0);
+		optlen = *(opt + 1) + 2;
+	}
+	if (opt + optlen <= lim)
+		return(optlen);
+
+	return(0);
+}
+
+static void
+inet6_insert_padopt(u_char *p, int len)
+{
+	switch(len) {
+	 case 0:
+		 return;
+	 case 1:
+		 p[0] = IP6OPT_PAD1;
+		 return;
+	 default:
+		 p[0] = IP6OPT_PADN;
+		 p[1] = len - 2; 
+		 memset(&p[2], 0, len - 2);
+		 return;
+	}
+}
+
+/*
+ * The following functions are defined in RFC3542, which is a successor
+ * of RFC2292.
+ */
+
+int
+inet6_opt_init(void *extbuf, socklen_t extlen)
+{
+	struct ip6_ext *ext = (struct ip6_ext *)extbuf;
+
+	if (extlen < 0 || (extlen % 8))
+		return(-1);
+
+	if (ext) {
+		if (extlen == 0)
+			return(-1);
+		ext->ip6e_len = (extlen >> 3) - 1;
+	}
+
+	return(2);		/* sizeof the next and the length fields */
+}
+
+int
+inet6_opt_append(void *extbuf, socklen_t extlen, int offset, u_int8_t type,
+		 socklen_t len, u_int8_t align, void **databufp)
+{
+	int currentlen = offset, padlen = 0;
+
+	/*
+	 * The option type must have a value from 2 to 255, inclusive.
+	 * (0 and 1 are reserved for the Pad1 and PadN options, respectively.)
+	 */
+	if (type < 2)
+		return(-1);
+
+	/*
+	 * The option data length must have a value between 0 and 255,
+	 * inclusive, and is the length of the option data that follows.
+	 */
+	if (len < 0 || len > 255)
+		return(-1);
+
+	/*
+	 * The align parameter must have a value of 1, 2, 4, or 8.
+	 * The align value can not exceed the value of len.
+	 */
+	if (align != 1 && align != 2 && align != 4 && align != 8)
+		return(-1);
+	if (align > len)
+		return(-1);
+
+	/* Calculate the padding length. */
+	currentlen += 2 + len;	/* 2 means "type + len" */
+	if (currentlen % align)
+		padlen = align - (currentlen % align);
+
+	/* The option must fit in the extension header buffer. */
+	currentlen += padlen;
+	if (extlen &&		/* XXX: right? */
+	    currentlen > extlen)
+		return(-1);
+
+	if (extbuf) {
+		u_int8_t *optp = (u_int8_t *)extbuf + offset;
+
+		if (padlen == 1) {
+			/* insert a Pad1 option */
+			*optp = IP6OPT_PAD1;
+			optp++;
+		}
+		else if (padlen > 0) {
+			/* insert a PadN option for alignment */
+			*optp++ = IP6OPT_PADN;
+			*optp++ = padlen - 2;
+			memset(optp, 0, padlen - 2);
+			optp += (padlen - 2);
+		}
+
+		*optp++ = type;
+		*optp++ = len;
+
+		*databufp = optp;
+	}
+
+	return(currentlen);
+}
+
+int
+inet6_opt_finish(void *extbuf, socklen_t extlen, int offset)
+{
+	int updatelen = offset > 0 ? (1 + ((offset - 1) | 7)) : 0;;
+
+	if (extbuf) {
+		u_int8_t *padp;
+		int padlen = updatelen - offset;
+
+		if (updatelen > extlen)
+			return(-1);
+
+		padp = (u_int8_t *)extbuf + offset;
+		if (padlen == 1)
+			*padp = IP6OPT_PAD1;
+		else if (padlen > 0) {
+			*padp++ = IP6OPT_PADN;
+			*padp++ = (padlen - 2);
+			memset(padp, 0, padlen - 2);
+		}
+	}
+
+	return(updatelen);
+}
+
+int
+inet6_opt_set_val(void *databuf, int offset, void *val, socklen_t vallen)
+{
+
+	memcpy((u_int8_t *)databuf + offset, val, vallen);
+	return(offset + vallen);
+}
+
+int
+inet6_opt_next(void *extbuf, socklen_t extlen, int offset, u_int8_t *typep,
+	       socklen_t *lenp, void **databufp)
+{
+	u_int8_t *optp, *lim;
+	int optlen;
+
+	/* Validate extlen. XXX: is the variable really necessary?? */
+	if (extlen == 0 || (extlen % 8))
+		return(-1);
+	lim = (u_int8_t *)extbuf + extlen;
+
+	/*
+	 * If this is the first time this function called for this options
+	 * header, simply return the 1st option.
+	 * Otherwise, search the option list for the next option.
+	 */
+	if (offset == 0) {
+		optp = (u_int8_t *)((struct ip6_hbh *)extbuf + 1);
+	}
+	else
+		optp = (u_int8_t *)extbuf + offset;
+
+	/* Find the next option skipping any padding options. */
+	while(optp < lim) {
+		switch(*optp) {
+		case IP6OPT_PAD1:
+			optp++;
+			break;
+		case IP6OPT_PADN:
+			if ((optlen = ip6optlen(optp, lim)) == 0)
+				goto optend;
+			optp += optlen;
+			break;
+		default:	/* found */
+			if ((optlen = ip6optlen(optp, lim)) == 0)
+				goto optend;
+			*typep = *optp;
+			*lenp = optlen - 2;
+			*databufp = optp + 2;
+			return(optp + optlen - (u_int8_t *)extbuf);
+		}
+	}
+
+  optend:
+	*databufp = NULL; /* for safety */
+	return(-1);
+}
+
+int
+inet6_opt_find(void *extbuf, socklen_t extlen, int offset, u_int8_t type,
+	       socklen_t *lenp, void **databufp)
+{
+	u_int8_t *optp, *lim;
+	int optlen;
+
+	/* Validate extlen. XXX: is the variable really necessary?? */
+	if (extlen == 0 || (extlen % 8))
+		return(-1);
+	lim = (u_int8_t *)extbuf + extlen;
+
+	/*
+	 * If this is the first time this function called for this options
+	 * header, simply return the 1st option.
+	 * Otherwise, search the option list for the next option.
+	 */
+	if (offset == 0) {
+		optp = (u_int8_t *)((struct ip6_hbh *)extbuf + 1);
+	}
+	else
+		optp = (u_int8_t *)extbuf + offset;
+
+	/* Find the specified option */
+	while(optp < lim) {
+		if ((optlen = ip6optlen(optp, lim)) == 0)
+			goto optend;
+
+		if (*optp == type) { /* found */
+			*lenp = optlen - 2;
+			*databufp = optp + 2;
+			return(optp + optlen - (u_int8_t *)extbuf);
+		}
+
+		optp += optlen;
+	}
+
+  optend:
+	*databufp = NULL; /* for safety */
+	return(-1);
+}
+
+int
+inet6_opt_get_val(void *databuf, int offset, void *val, socklen_t vallen)
+{
+
+	/* we can't assume alignment here */
+	memcpy(val, (u_int8_t *)databuf + offset, vallen);
+
+	return(offset + vallen);
+}