Fix an unaligned access error on BeagleBone Black with FreeBSD.

Thanks to Guy Yur for the patch.

diff --git a/dhcp6.c b/dhcp6.c
index 562e4e5f74a9a4dcfe7e5b1aa485e994e8dfa2c3..b4bf1df182404b1a84447c88f236212822c936fe 100644 (file)
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -433,7 +433,7 @@ dhcp6_makemessage(struct interface *ifp)
        const struct dhcp6_option *si, *unicast;
        size_t l, n, len, ml, auth_len;
        uint8_t u8, type;
-       uint16_t *u16, n_options;
+       uint16_t u16, n_options;
        struct if_options *ifo;
        const struct dhcp_opt *opt, *opt2;
        uint8_t IA, *p;
@@ -493,7 +493,7 @@ dhcp6_makemessage(struct interface *ifp)
                            has_option_mask(ifo->requestmask6, opt->option)))
                        {
                                n_options++;
-                               len += sizeof(*u16);
+                               len += sizeof(u16);
                        }
                }
                for (l = 0, opt = ifo->dhcp6_override;
@@ -505,12 +505,12 @@ dhcp6_makemessage(struct interface *ifp)
                            has_option_mask(ifo->requestmask6, opt->option)))
                        {
                                n_options++;
-                               len += sizeof(*u16);
+                               len += sizeof(u16);
                        }
                }
                if (dhcp6_findselfsla(ifp, NULL)) {
                        n_options++;
-                       len += sizeof(*u16);
+                       len += sizeof(u16);
                }
                if (len)
                        len += sizeof(*o);
@@ -804,7 +804,7 @@ dhcp6_makemessage(struct interface *ifp)
                        o = D6_NEXT_OPTION(o);
                        o->code = htons(D6_OPTION_ORO);
                        o->len = 0;
-                       u16 = (uint16_t *)(void *)D6_OPTION_DATA(o);
+                       p = D6_OPTION_DATA(o);
                        for (l = 0, opt = ifp->ctx->dhcp6_opts;
                            l < ifp->ctx->dhcp6_opts_len;
                            l++, opt++)
@@ -823,8 +823,10 @@ dhcp6_makemessage(struct interface *ifp)
                                    has_option_mask(ifo->requestmask6,
                                        opt->option)))
                                {
-                                       *u16++ = htons(opt->option);
-                                       o->len += sizeof(*u16);
+                                       u16 = htons(opt->option);
+                                       memcpy(p, &u16, sizeof(u16));
+                                       p += sizeof(u16);
+                                       o->len += sizeof(u16);
                                }
                        }
                        for (l = 0, opt = ifo->dhcp6_override;
@@ -836,13 +838,17 @@ dhcp6_makemessage(struct interface *ifp)
                                    has_option_mask(ifo->requestmask6,
                                        opt->option)))
                                {
-                                       *u16++ = htons(opt->option);
-                                       o->len += sizeof(*u16);
+                                       u16 = htons(opt->option);
+                                       memcpy(p, &u16, sizeof(u16));
+                                       p += sizeof(u16);
+                                       o->len += sizeof(u16);
                                }
                        }
                        if (dhcp6_findselfsla(ifp, NULL)) {
-                               *u16++ = htons(D6_OPTION_PD_EXCLUDE);
-                               o->len += sizeof(*u16);
+                               u16 = htons(D6_OPTION_PD_EXCLUDE);
+                               memcpy(p, &u16, sizeof(u16));
+                               p += sizeof(u16);
+                               o->len += sizeof(u16);
                        }
                        o->len = htons(o->len);
                }