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-rw-r--r--lib/libc/net/ip6opt.c610
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diff --git a/lib/libc/net/ip6opt.c b/lib/libc/net/ip6opt.c
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+/* $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 <sys/param.h>
+#include <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(nbytes)
+ 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(bp, cmsgp, type)
+ 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(cmsg, typep, multx, plusy)
+ 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(cmsg, datalen, multx, plusy)
+ 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(cmsg, tptrp)
+ 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(cmsg, tptrp, type)
+ 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(opt, lim)
+ u_int8_t *opt, *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);
+}
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