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https://github.com/opnsense/src.git
synced 2026-05-28 04:12:45 -04:00
netinet6: Implement in6_cksum_partial() using m_apply()
This ensures that in6_cksum_partial() can be applied to unmapped mbufs, which can happen at least when icmp6_reflect() quotes a packet. The basic idea is to restructure in6_cksum_partial() to operate on one mbuf at a time. If the buffer length is odd or unaligned, an extra residual byte may be returned, to be incorporated into the checksum when processing the next buffer. PR: 268400 Reviewed by: cy MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D40598
This commit is contained in:
Mark Johnston
parent
fc915f1be1
commit
6775ef4188
2 changed files with 139 additions and 167 deletions
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@ -659,10 +659,10 @@ struct ip6_mtuinfo {
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struct cmsghdr;
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struct ip6_hdr;
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int in6_cksum(struct mbuf *, uint8_t, uint32_t, uint32_t);
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int in6_cksum_partial(struct mbuf *, uint8_t, uint32_t, uint32_t, uint32_t);
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int in6_cksum_pseudo(struct ip6_hdr *, uint32_t, uint8_t, uint16_t);
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int in6_cksum(struct mbuf *, u_int8_t, u_int32_t, u_int32_t);
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int in6_cksum_partial(struct mbuf *, u_int8_t, u_int32_t, u_int32_t,
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u_int32_t);
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int in6_localaddr(struct in6_addr *);
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int in6_localip(struct in6_addr *);
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bool in6_localip_fib(struct in6_addr *, uint16_t);
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@ -82,6 +82,16 @@ __FBSDID("$FreeBSD$");
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#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
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#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; (void)ADDCARRY(sum);}
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union l_util {
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uint16_t s[2];
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uint32_t l;
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};
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union s_util {
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uint8_t c[2];
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uint16_t s;
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};
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static int
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_in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
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{
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@ -131,17 +141,115 @@ _in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
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int
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in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
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{
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union l_util l_util;
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int sum;
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union {
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u_int16_t s[2];
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u_int32_t l;
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} l_util;
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sum = _in6_cksum_pseudo(ip6, len, nxt, csum);
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REDUCE;
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return (sum);
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}
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static int
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in6_cksumdata(void *data, int *lenp, uint8_t *residp, int rlen)
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{
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union l_util l_util;
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union s_util s_util;
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uint16_t *w;
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int len, sum;
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bool byte_swapped;
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KASSERT(*lenp >= 0, ("%s: negative len %d", __func__, *lenp));
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KASSERT(rlen == 0 || rlen == 1, ("%s: rlen %d", __func__, rlen));
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len = *lenp;
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sum = 0;
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if (len == 0) {
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len = rlen;
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goto out;
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}
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byte_swapped = false;
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w = data;
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/*
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* Do we have a residual byte left over from the previous buffer?
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*/
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if (rlen == 1) {
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s_util.c[0] = *residp;
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s_util.c[1] = *(uint8_t *)w;
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sum += s_util.s;
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w = (uint16_t *)((uint8_t *)w + 1);
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len--;
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rlen = 0;
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}
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/*
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* Force to even boundary.
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*/
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if ((1 & (uintptr_t)w) && len > 0) {
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REDUCE;
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sum <<= 8;
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s_util.c[0] = *(uint8_t *)w;
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w = (uint16_t *)((uint8_t *)w + 1);
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len--;
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byte_swapped = true;
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}
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/*
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* Unroll the loop to make overhead from branches &c small.
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*/
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while ((len -= 32) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
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sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
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sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
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w += 16;
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}
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len += 32;
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while ((len -= 8) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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w += 4;
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}
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len += 8;
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if (len == 0 && !byte_swapped)
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goto out;
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REDUCE;
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while ((len -= 2) >= 0) {
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sum += *w++;
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}
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if (byte_swapped) {
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REDUCE;
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sum <<= 8;
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if (len == -1) {
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s_util.c[1] = *(uint8_t *)w;
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sum += s_util.s;
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} else /* len == -2 */
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*residp = s_util.c[0];
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len++;
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} else if (len == -1)
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*residp = *(uint8_t *)w;
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out:
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*lenp = len & 1;
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return (sum);
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}
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struct in6_cksum_partial_arg {
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int sum;
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int rlen;
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uint8_t resid;
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};
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static int
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in6_cksum_partial_one(void *_arg, void *data, u_int len)
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{
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struct in6_cksum_partial_arg *arg = _arg;
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arg->sum += in6_cksumdata(data, &len, &arg->resid, arg->rlen);
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arg->rlen = len;
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return (0);
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}
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/*
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* m MUST contain a contiguous IP6 header.
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* off is an offset where TCP/UDP/ICMP6 header starts.
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@ -150,33 +258,29 @@ in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
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* cov is the number of bytes to be taken into account for the checksum
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*/
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int
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in6_cksum_partial(struct mbuf *m, u_int8_t nxt, u_int32_t off,
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u_int32_t len, u_int32_t cov)
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in6_cksum_partial(struct mbuf *m, uint8_t nxt, uint32_t off, uint32_t len,
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uint32_t cov)
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{
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struct in6_cksum_partial_arg arg;
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union l_util l_util;
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union s_util s_util;
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struct ip6_hdr *ip6;
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u_int16_t *w, scope;
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int byte_swapped, mlen;
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uint16_t *w, scope;
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int sum;
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union {
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u_int16_t phs[4];
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uint16_t phs[4];
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struct {
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u_int32_t ph_len;
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u_int8_t ph_zero[3];
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u_int8_t ph_nxt;
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uint32_t ph_len;
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uint8_t ph_zero[3];
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uint8_t ph_nxt;
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} __packed ph;
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} uph;
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union {
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u_int8_t c[2];
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u_int16_t s;
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} s_util;
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union {
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u_int16_t s[2];
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u_int32_t l;
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} l_util;
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/* Sanity check. */
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KASSERT(m->m_pkthdr.len >= off + len, ("%s: mbuf len (%d) < off(%d)+"
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"len(%d)", __func__, m->m_pkthdr.len, off, len));
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KASSERT(m->m_len >= sizeof(*ip6),
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("%s: mbuf len %d < sizeof(ip6)", __func__, m->m_len));
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/*
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* First create IP6 pseudo header and calculate a summary.
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@ -193,7 +297,7 @@ in6_cksum_partial(struct mbuf *m, u_int8_t nxt, u_int32_t off,
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/* IPv6 source address. */
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scope = in6_getscope(&ip6->ip6_src);
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w = (u_int16_t *)&ip6->ip6_src;
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w = (uint16_t *)&ip6->ip6_src;
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
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if (scope != 0)
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@ -201,158 +305,26 @@ in6_cksum_partial(struct mbuf *m, u_int8_t nxt, u_int32_t off,
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/* IPv6 destination address. */
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scope = in6_getscope(&ip6->ip6_dst);
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w = (u_int16_t *)&ip6->ip6_dst;
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w = (uint16_t *)&ip6->ip6_dst;
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
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if (scope != 0)
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sum -= scope;
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/*
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* Secondly calculate a summary of the first mbuf excluding offset.
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* Loop over the rest of the mbuf chain and compute the rest of the
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* checksum. m_apply() handles unmapped mbufs.
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*/
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while (off > 0) {
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if (m->m_len <= off)
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off -= m->m_len;
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else
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break;
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m = m->m_next;
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}
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w = (u_int16_t *)(mtod(m, u_char *) + off);
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mlen = m->m_len - off;
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if (cov < mlen)
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mlen = cov;
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cov -= mlen;
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/*
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* Force to even boundary.
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*/
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if ((1 & (long)w) && (mlen > 0)) {
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REDUCE;
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sum <<= 8;
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s_util.c[0] = *(u_char *)w;
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w = (u_int16_t *)((char *)w + 1);
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mlen--;
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byte_swapped = 1;
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} else
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byte_swapped = 0;
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arg.sum = sum;
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arg.rlen = 0;
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(void)m_apply(m, off, cov, in6_cksum_partial_one, &arg);
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sum = arg.sum;
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/*
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* Unroll the loop to make overhead from
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* branches &c small.
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* Handle a residual byte.
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*/
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while ((mlen -= 32) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
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sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
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sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
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w += 16;
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}
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mlen += 32;
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while ((mlen -= 8) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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w += 4;
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}
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mlen += 8;
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if (mlen == 0 && byte_swapped == 0)
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goto next;
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REDUCE;
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while ((mlen -= 2) >= 0) {
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sum += *w++;
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}
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if (byte_swapped) {
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REDUCE;
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sum <<= 8;
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byte_swapped = 0;
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if (mlen == -1) {
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s_util.c[1] = *(char *)w;
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sum += s_util.s;
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mlen = 0;
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} else
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mlen = -1;
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} else if (mlen == -1)
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s_util.c[0] = *(char *)w;
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next:
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m = m->m_next;
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/*
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* Lastly calculate a summary of the rest of mbufs.
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*/
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for (;m && cov; m = m->m_next) {
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if (m->m_len == 0)
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continue;
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w = mtod(m, u_int16_t *);
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if (mlen == -1) {
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/*
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* The first byte of this mbuf is the continuation
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* of a word spanning between this mbuf and the
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* last mbuf.
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*
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* s_util.c[0] is already saved when scanning previous
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* mbuf.
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*/
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s_util.c[1] = *(char *)w;
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sum += s_util.s;
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w = (u_int16_t *)((char *)w + 1);
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mlen = m->m_len - 1;
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cov--;
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} else
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mlen = m->m_len;
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if (cov < mlen)
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mlen = cov;
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cov -= mlen;
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/*
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* Force to even boundary.
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*/
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if ((1 & (long) w) && (mlen > 0)) {
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REDUCE;
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sum <<= 8;
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s_util.c[0] = *(u_char *)w;
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w = (u_int16_t *)((char *)w + 1);
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mlen--;
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byte_swapped = 1;
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}
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/*
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* Unroll the loop to make overhead from
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* branches &c small.
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*/
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while ((mlen -= 32) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
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sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
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sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
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w += 16;
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}
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mlen += 32;
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while ((mlen -= 8) >= 0) {
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sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
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w += 4;
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}
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mlen += 8;
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if (mlen == 0 && byte_swapped == 0)
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continue;
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REDUCE;
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while ((mlen -= 2) >= 0) {
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sum += *w++;
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}
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if (byte_swapped) {
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REDUCE;
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sum <<= 8;
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byte_swapped = 0;
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if (mlen == -1) {
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s_util.c[1] = *(char *)w;
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sum += s_util.s;
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mlen = 0;
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} else
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mlen = -1;
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} else if (mlen == -1)
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s_util.c[0] = *(char *)w;
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}
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if (cov)
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panic("in6_cksum: out of data");
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if (mlen == -1) {
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/* The last mbuf has odd # of bytes. Follow the
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standard (the odd byte may be shifted left by 8 bits
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or not as determined by endian-ness of the machine) */
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if (arg.rlen == 1) {
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s_util.c[0] = arg.resid;
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s_util.c[1] = 0;
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sum += s_util.s;
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}
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@ -361,7 +333,7 @@ in6_cksum_partial(struct mbuf *m, u_int8_t nxt, u_int32_t off,
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}
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int
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in6_cksum(struct mbuf *m, u_int8_t nxt, u_int32_t off, u_int32_t len)
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in6_cksum(struct mbuf *m, uint8_t nxt, uint32_t off, uint32_t len)
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{
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return (in6_cksum_partial(m, nxt, off, len, len));
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}
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