diff options
Diffstat (limited to 'newlib/libc/sys/linux/net/ip6opt.c')
| -rw-r--r-- | newlib/libc/sys/linux/net/ip6opt.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/net/ip6opt.c b/newlib/libc/sys/linux/net/ip6opt.c new file mode 100644 index 000000000..f3f51d507 --- /dev/null +++ b/newlib/libc/sys/linux/net/ip6opt.c @@ -0,0 +1,387 @@ +/* + * 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> +#include <sys/types.h> + +#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 (typep[0] > 255) + 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; + /* 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; + /* 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; + } +} |