diff options
Diffstat (limited to 'src/libhydra/plugins/kernel_netlink')
| -rw-r--r-- | src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c | 21 | ||||
| -rw-r--r-- | src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h | 11 |
2 files changed, 32 insertions, 0 deletions
diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c index 729e08d5a..fd00c23af 100644 --- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c +++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.c @@ -304,3 +304,24 @@ void netlink_add_attribute(struct nlmsghdr *hdr, int rta_type, chunk_t data, memcpy(RTA_DATA(rta), data.ptr, data.len); hdr->nlmsg_len = NLMSG_ALIGN(hdr->nlmsg_len) + rta->rta_len; } + +/** + * Described in header. + */ +void* netlink_reserve(struct nlmsghdr *hdr, int buflen, int type, int len) +{ + struct rtattr *rta; + + if (NLMSG_ALIGN(hdr->nlmsg_len) + RTA_LENGTH(len) > buflen) + { + DBG1(DBG_KNL, "unable to add attribute, buffer too small"); + return NULL; + } + + rta = ((void*)hdr) + NLMSG_ALIGN(hdr->nlmsg_len); + rta->rta_type = type; + rta->rta_len = RTA_LENGTH(len); + hdr->nlmsg_len = NLMSG_ALIGN(hdr->nlmsg_len) + rta->rta_len; + + return RTA_DATA(rta); +} diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h index f5721dfbb..8be935bc3 100644 --- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h +++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h @@ -76,4 +76,15 @@ netlink_socket_t *netlink_socket_create(int protocol); void netlink_add_attribute(struct nlmsghdr *hdr, int rta_type, chunk_t data, size_t buflen); +/** + * Reserve space in a netlink message for given size and type, returning buffer. + * + * @param hdr netlink message + * @param buflen size of full netlink buffer + * @param type RTA type + * @param len length of RTA data + * @return buffer to len bytes of attribute data, NULL on error + */ +void* netlink_reserve(struct nlmsghdr *hdr, int buflen, int type, int len); + #endif /* KERNEL_NETLINK_SHARED_H_ */ |