void multi_link_get_iface_info(struct multi_link_info *li){
//MNL_SOCKET_BUFFER_SIZE is 8k, which is the max nlmsg size (see
//linux/netlink.h)
uint8_t buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct rtgenmsg *rt;
uint32_t seq;
//It seems like I cant request one interface, has to dump!
////Play with this later and see what is up
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETADDR;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL); //How will this work with event? Send 0?
rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
//I need all interfaces, also those without IP (check)
rt->rtgen_family = AF_UNSPEC;
if(mnl_socket_sendto(multi_link_nl_request, nlh, nlh->nlmsg_len) < 0){
MULTI_DEBUG_PRINT(stderr, "Cannot request info dump\n");
return;
}
if(li->state == LINK_DOWN_PPP)
multi_link_filter(seq, multi_link_filter_ppp, (void*) li);
else if(li->state == LINK_DOWN_AP)
multi_link_filter(seq, multi_link_filter_ap, (void*) li);
}
static int32_t multi_link_flush_links(){
struct ip_info ip_info;
uint8_t buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct rtgenmsg *rt;
uint32_t seq;
memset(buf, 0, MNL_SOCKET_BUFFER_SIZE);
memset(&ip_info, 0, sizeof(ip_info));
//Initialize list
TAILQ_INIT(&(ip_info.ip_addr_n));
TAILQ_INIT(&(ip_info.ip_rules_n));
TAILQ_INIT(&(ip_info.ip_routes_n));
//Sets room for one nlmsghdr in buffer buf
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETADDR;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL); //How will this work with event? Send 0?
rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
rt->rtgen_family = AF_INET; //I need all interfaces
//Address
if(mnl_socket_sendto(multi_link_nl_request, nlh, nlh->nlmsg_len) < 0){
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Cannot request address dump\n");
return EXIT_FAILURE;
}
multi_link_filter(seq, multi_link_filter_ipaddr, &ip_info);
//Rules
nlh->nlmsg_type = RTM_GETRULE;
if(mnl_socket_sendto(multi_link_nl_request, nlh, nlh->nlmsg_len) < 0){
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Cannot request rules dump\n");
return EXIT_FAILURE;
}
multi_link_filter(seq, multi_link_filter_iprules, &ip_info);
//Routes
nlh->nlmsg_type = RTM_GETROUTE;
if(mnl_socket_sendto(multi_link_nl_request, nlh, nlh->nlmsg_len) < 0){
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Cannot request rules dump\n");
return EXIT_FAILURE;
}
multi_link_filter(seq, multi_link_filter_iproutes, &ip_info);
/* Remove existing information and free memory */
multi_link_del_info(ip_info.ip_routes_n, RTM_DELROUTE);
multi_link_del_info(ip_info.ip_rules_n, RTM_DELRULE);
multi_link_del_info(ip_info.ip_addr_n, RTM_DELADDR);
multi_link_free_ip_info(&ip_info);
return EXIT_SUCCESS;
}
static void multi_link_populate_links_list(){
//MNL_SOCKET_BUFFER_SIZE is 8k, which is the max nlmsg size (see
//linux/netlink.h)
uint8_t buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct rtgenmsg *rt;
uint32_t seq;
memset(buf, 0, MNL_SOCKET_BUFFER_SIZE);
//Sets room for one nlmsghdr in buffer buf
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETLINK;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL); //How will this work with event? Send 0?
rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
rt->rtgen_family = AF_UNSPEC; //I need all interfaces
if(mnl_socket_sendto(multi_link_nl_request, nlh, nlh->nlmsg_len) < 0){
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Cannot request info dump\n");
return;
}
multi_link_filter(seq, multi_link_filter_links, NULL);
}
//Addresses and routes are always deleted when an interface goes down, but not
//rules. Netlink is not reliable and there are scenarios where we will loose
//messages and not clean up properly. We therefore need to make sure that there
//exists no rules poining to this address/interface
static int32_t multi_link_rules_sanity(struct multi_link_info *li)
{
struct ip_info ip_info;
uint8_t buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct rtgenmsg *rt;
uint32_t seq;
int32_t ret;
struct multi_link_filter_iprule filter_iprule = {0};
memset(buf, 0, MNL_SOCKET_BUFFER_SIZE);
memset(&ip_info, 0, sizeof(ip_info));
//I am lazy and will use ip_info for now
TAILQ_INIT(&(ip_info.ip_rules_n));
filter_iprule.li = li;
ip_info.data = &filter_iprule;
//Sets room for one nlmsghdr in buffer buf
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETRULE;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL);
rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
rt->rtgen_family = AF_INET; //Multi only supports v4
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Will check for dirty rules\n");
if(mnl_socket_sendto(multi_link_nl_request, nlh, nlh->nlmsg_len) < 0){
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Cannot request rules dump\n");
return EXIT_FAILURE;
}
ret = multi_link_filter(seq, multi_link_filter_iprules_addr, &ip_info);
if (ret) {
//Some rules might have been added
multi_link_free_ip_info(&ip_info);
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Sanity check failed (memory)\n");
return EXIT_FAILURE;
}
if (!ip_info.ip_rules_n.tqh_first)
return EXIT_SUCCESS;
MULTI_DEBUG_PRINT_SYSLOG(stderr, "Will delete dirty rules\n");
multi_link_del_info(ip_info.ip_rules_n, RTM_DELRULE);
multi_link_free_ip_info(&ip_info);
return EXIT_SUCCESS;
}
