+
+/*
+ * IP socket option processing.
+ */
+ip_ctloutput(op, so, level, optname, m)
+ int op;
+ struct socket *so;
+ int level, optname;
+ struct mbuf **m;
+{
+ int error = 0;
+ struct inpcb *inp = sotoinpcb(so);
+
+ if (level != IPPROTO_IP)
+ error = EINVAL;
+ else switch (op) {
+
+ case PRCO_SETOPT:
+ switch (optname) {
+ case IP_OPTIONS:
+ return (ip_pcbopts(&inp->inp_options, *m));
+
+ default:
+ error = EINVAL;
+ break;
+ }
+ break;
+
+ case PRCO_GETOPT:
+ switch (optname) {
+ case IP_OPTIONS:
+ *m = m_get(M_WAIT, MT_SOOPTS);
+ if (inp->inp_options) {
+ (*m)->m_len = inp->inp_options->m_len;
+ bcopy(mtod(inp->inp_options, caddr_t),
+ mtod(*m, caddr_t), (unsigned)(*m)->m_len);
+ } else
+ (*m)->m_len = 0;
+ break;
+ default:
+ error = EINVAL;
+ break;
+ }
+ break;
+ }
+ if (op == PRCO_SETOPT && *m)
+ (void)m_free(*m);
+ return (error);
+}
+
+/*
+ * Set up IP options in pcb for insertion in output packets.
+ * Store in mbuf with pointer in pcbopt, adding pseudo-option
+ * with destination address if source routed.
+ */
+ip_pcbopts(pcbopt, m)
+ struct mbuf **pcbopt;
+ register struct mbuf *m;
+{
+ register cnt, optlen;
+ register u_char *cp;
+ u_char opt;
+
+ /* turn off any old options */
+ if (*pcbopt)
+ (void)m_free(*pcbopt);
+ *pcbopt = 0;
+ if (m == (struct mbuf *)0 || m->m_len == 0) {
+ /*
+ * Only turning off any previous options.
+ */
+ if (m)
+ (void)m_free(m);
+ return (0);
+ }
+
+#ifndef vax
+ if (m->m_len % sizeof(long))
+ goto bad;
+#endif
+ /*
+ * IP first-hop destination address will be stored before
+ * actual options; move other options back
+ * and clear it when none present.
+ */
+ if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
+ goto bad;
+ cnt = m->m_len;
+ m->m_len += sizeof(struct in_addr);
+ cp = mtod(m, u_char *) + sizeof(struct in_addr);
+ ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt);
+ bzero(mtod(m, caddr_t), sizeof(struct in_addr));
+
+ for (; cnt > 0; cnt -= optlen, cp += optlen) {
+ opt = cp[IPOPT_OPTVAL];
+ if (opt == IPOPT_EOL)
+ break;
+ if (opt == IPOPT_NOP)
+ optlen = 1;
+ else {
+ optlen = cp[IPOPT_OLEN];
+ if (optlen <= IPOPT_OLEN || optlen > cnt)
+ goto bad;
+ }
+ switch (opt) {
+
+ default:
+ break;
+
+ case IPOPT_LSRR:
+ case IPOPT_SSRR:
+ /*
+ * user process specifies route as:
+ * ->A->B->C->D
+ * D must be our final destination (but we can't
+ * check that since we may not have connected yet).
+ * A is first hop destination, which doesn't appear in
+ * actual IP option, but is stored before the options.
+ */
+ if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
+ goto bad;
+ m->m_len -= sizeof(struct in_addr);
+ cnt -= sizeof(struct in_addr);
+ optlen -= sizeof(struct in_addr);
+ cp[IPOPT_OLEN] = optlen;
+ /*
+ * Move first hop before start of options.
+ */
+ bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
+ sizeof(struct in_addr));
+ /*
+ * Then copy rest of options back
+ * to close up the deleted entry.
+ */
+ ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] +
+ sizeof(struct in_addr)),
+ (caddr_t)&cp[IPOPT_OFFSET+1],
+ (unsigned)cnt + sizeof(struct in_addr));
+ break;
+ }
+ }
+ if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
+ goto bad;
+ *pcbopt = m;
+ return (0);
+
+bad:
+ (void)m_free(m);
+ return (EINVAL);
+}
projects / unix-history / blobdiff