Commiting the rework I have done until now.

But I will remove the ack stuff, too complicated.

Signed-off-by: Benjamin Cama <benoar@dolka.fr>

diff --git a/l2tpns.c b/l2tpns.c
index 7548771..d849711 100644 (file)
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -577,10 +577,9 @@ static ssize_t netlink_recv(char *buf, ssize_t len)
        return recvmsg(nlfd, &msg, 0);
 }
 
-static ssize_t netlink_check_ack(struct nlmsghdr *ack_nh, int msg_count)
+static ssize_t netlink_check_ack(struct nlmsghdr *ack_nh, ssize_t len, int msg_count)
 {
-       ssize_t len;
-       uint32_t seqnum;
+       uint32_t seqnum = 0;
 
        // expect ack
        for (; NLMSG_OK (ack_nh, len); ack_nh = NLMSG_NEXT (ack_nh, len))
@@ -600,6 +599,9 @@ static ssize_t netlink_check_ack(struct nlmsghdr *ack_nh, int msg_count)
                                --msg_count;
                                if (errmsg->msg.nlmsg_seq > seqnum);
                                        seqnum = errmsg->msg.nlmsg_seq;
+                               // if this is a single message, return now
+                               if (!(ack_nh->nlmsg_flags & NLM_F_MULTI))
+                                       return msg_count != 0 || seqnum != nlseqnum;
                        }
                }
                else
@@ -617,6 +619,8 @@ static void inittun(void)
        struct ifinfomsg ifinfo;
        struct ifreq ifr;
        char buf[4096];
+       ssize_t len;
+       struct nlmsghdr *resp_nh;
 
        memset(&ifr, 0, sizeof(ifr));
        ifr.ifr_flags = IFF_TUN;
@@ -641,14 +645,12 @@ static void inittun(void)
 
        {
                // get the interface index
-               ssize_t len;
                struct {
                        struct nlmsghdr nh;
                        struct ifinfomsg ifinfo __attribute__ ((aligned(NLMSG_ALIGNTO)));
                        struct rtattr ifname_rta __attribute__ ((aligned(RTA_ALIGNTO)));
                        char ifname[IFNAMSIZ];
                } req;
-               struct nlmsghdr *resp_nh;
 
                req.nh.nlmsg_type = RTM_GETLINK;
                req.nh.nlmsg_flags = NLM_F_REQUEST;
@@ -659,6 +661,9 @@ static void inittun(void)
                req.ifname_rta.rta_type = IFLA_IFNAME;
                strncpy(req.ifname, config->tundevice, IFNAMSIZ-1);
 
+               req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo)
+                               + req.ifname_rta.rta_len);
+
                if(netlink_send(&req.nh, 0) < 0 || (len = netlink_recv(buf, sizeof(buf))) < 0)
                {
                        LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
@@ -666,151 +671,188 @@ static void inittun(void)
                }
 
                resp_nh = (struct nlmsghdr *)buf;
-               if (NLMSG_OK (resp_nh, len) && resp_nh->nlmsg_type == RTM_GETLINK)
-               {
-                       memcpy(&ifinfo, NLMSG_DATA(resp_nh), sizeof(ifinfo));
-                       // got index
-                       tunidx = ifinfo.ifi_index;
-               }
-               else
+               if (!NLMSG_OK (resp_nh, len))
                {
                        LOG(0, 0, 0, "Malformed answer getting tun ifindex\n");
                        exit(1);
                }
+
+               memcpy(&ifinfo, NLMSG_DATA(resp_nh), sizeof(ifinfo));
+               // got index
+               tunidx = ifinfo.ifi_index;
        }
        {
                ssize_t err;
                struct {
                        // interface setting
                        struct nlmsghdr nh;
-                       struct ifinfomsg ifinfo __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct rtattr txqlen_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-                       uint32_t txqlen;
-                       struct rtattr mtu_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-                       uint32_t mtu;
-
-                       // IPv4 address
-                       struct nlmsghdr addr_nh __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct ifaddrmsg ifaddr __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct rtattr addr_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-                       struct in_addr addr;
-
-                       // IPv6 LL address
-                       struct nlmsghdr lladdr6_nh __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct ifaddrmsg llifaddr6 __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct rtattr lladdr6_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-                       struct in6_addr lladdr6;
-
-                       // IPv6 global address
-                       struct nlmsghdr addr6_nh __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct ifaddrmsg ifaddr6 __attribute__ ((aligned(NLMSG_ALIGNTO)));
-                       struct rtattr addr6_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-                       struct in6_addr addr6;
-
-                       // end header
-                       struct nlmsghdr end_nh __attribute__ ((aligned(NLMSG_ALIGNTO)));
+                       union {
+                               struct ifinfomsg ifinfo;
+                               struct ifaddrmsg ifaddr;
+                       } ifmsg __attribute__ ((aligned(NLMSG_ALIGNTO)));
+                       char rtdata[32]; // 32 should be enough
                } req;
-               char buf[4096];
+               struct {
+                       struct rtattr rta;
+                       uint32_t u32 __attribute__ ((aligned(RTA_ALIGNTO)));;
+               } u32_attr;
+               struct {
+                       struct rtattr rta;
+                       struct in_addr addr __attribute__ ((aligned(RTA_ALIGNTO)));;
+               } ipv4_attr;
+               struct {
+                       struct rtattr rta;
+                       struct in6_addr addr6 __attribute__ ((aligned(RTA_ALIGNTO)));;
+               } ipv6_attr;
+               char buf[256];
+               ssize_t buf_len;
+               char *buf_ptr;
 
                memset(&req, 0, sizeof(req));
 
-               req.nh.nlmsg_type = RTM_NEWLINK;
-               req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_REPLACE | NLM_F_MULTI;
+               req.nh.nlmsg_type = RTM_SETLINK;
+               req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_MULTI;
 
-               req.ifinfo = ifinfo;
-               req.ifinfo.ifi_flags |= IFF_UP; // set interface up
-               req.ifinfo.ifi_change = IFF_UP; // only change this flag
+               req.ifmsg.ifinfo = ifinfo;
+               req.ifmsg.ifinfo.ifi_flags |= IFF_UP; // set interface up
+               req.ifmsg.ifinfo.ifi_change = IFF_UP; // only change this flag
 
-               req.txqlen_rta.rta_len = RTA_LENGTH(sizeof(req.txqlen));
-               req.txqlen_rta.rta_type = IFLA_TXQLEN;
+               buf_ptr = NLMSG_DATA(&req.nh) + sizeof(req.ifmsg.ifinfo);
+
+               u32_attr.rta.rta_len = RTA_LENGTH(sizeof(u32_attr.u32));
+               u32_attr.rta.rta_type = IFLA_TXQLEN;
                /* Bump up the qlen to deal with bursts from the network */
-               req.txqlen = 1000;
+               u32_attr.u32 = 1000;
+               memcpy(buf_ptr, &u32_attr, sizeof(u32_attr));
+
+               buf_ptr += RTA_ALIGN(u32_attr.rta.rta_len);
 
-               req.mtu_rta.rta_len = RTA_LENGTH(sizeof(req.txqlen));
-               req.mtu_rta.rta_type = IFLA_MTU;
+               u32_attr.rta.rta_len = RTA_LENGTH(sizeof(u32_attr.u32));
+               u32_attr.rta.rta_type = IFLA_MTU;
                /* set MTU to modem MRU */
-               req.mtu = MRU;
+               u32_attr.u32 = MRU;
+               memcpy(buf_ptr, &u32_attr, sizeof(u32_attr));
 
-               req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo)
-                               + req.txqlen_rta.rta_len
-                               + req.mtu_rta.rta_len);
+               req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifinfo)
+                               + u32_attr.rta.rta_len * 2);
+
+               if (netlink_send(&req.nh, 1) < 0)
+               {
+                       LOG(0, 0, 0, "Error setting up tun device interface: %s\n", strerror(errno));
+                       exit(1);
+               }
+
+               memset(&req, 0, sizeof(req));
 
-               req.addr_nh.nlmsg_type = RTM_NEWADDR;
-               req.addr_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+               req.nh.nlmsg_type = RTM_NEWADDR;
+               req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
 
-               req.ifaddr.ifa_family = AF_INET;
-               req.ifaddr.ifa_prefixlen = 32;
-               req.ifaddr.ifa_index = ifinfo.ifi_index;
+               req.ifmsg.ifaddr.ifa_family = AF_INET;
+               req.ifmsg.ifaddr.ifa_prefixlen = 32;
+               req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
 
-               req.addr_rta.rta_len = RTA_LENGTH(sizeof(req.addr));
-               req.addr_rta.rta_type = IFA_ADDRESS;
-               req.addr.s_addr = config->bind_address ?
+               ipv4_attr.rta.rta_len = RTA_LENGTH(sizeof(ipv4_attr.addr));
+               ipv4_attr.rta.rta_type = IFA_ADDRESS;
+               ipv4_attr.addr.s_addr = config->bind_address ?
                        config->bind_address : 0x01010101; // 1.1.1.1
+               memcpy(NLMSG_DATA(&req.nh) + sizeof(req.ifmsg.ifaddr), &ipv4_attr, sizeof(ipv4_attr));
 
-               req.addr_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
-                               + req.addr_rta.rta_len);
+               req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr)
+                               + ipv4_attr.rta.rta_len);
+
+               if (netlink_send(&req.nh, 1) < 0)
+               {
+                       LOG(0, 0, 0, "Error setting up tun device IPv4 address: %s\n", strerror(errno));
+                       exit(1);
+               }
+
+               memset(&req, 0, sizeof(req));
 
                // Only setup IPv6 on the tun device if we have a configured prefix
                if (config->ipv6_prefix.s6_addr[0]) {
-                       req.lladdr6_nh.nlmsg_type = RTM_NEWADDR;
-                       req.lladdr6_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+                       req.nh.nlmsg_type = RTM_NEWADDR;
+                       req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
 
-                       req.llifaddr6.ifa_family = AF_INET6;
-                       req.llifaddr6.ifa_prefixlen = 64;
-                       req.llifaddr6.ifa_scope = RT_SCOPE_LINK;
-                       req.llifaddr6.ifa_index = ifinfo.ifi_index;
+                       req.ifmsg.ifaddr.ifa_family = AF_INET6;
+                       req.ifmsg.ifaddr.ifa_prefixlen = 64;
+                       req.ifmsg.ifaddr.ifa_scope = RT_SCOPE_LINK;
+                       req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
 
-                       req.lladdr6_rta.rta_len = RTA_LENGTH(sizeof(req.lladdr6));
-                       req.lladdr6_rta.rta_type = IFA_LOCAL;
+                       ipv6_attr.rta.rta_len = RTA_LENGTH(sizeof(ipv6_attr.addr6));
+                       ipv6_attr.rta.rta_type = IFA_LOCAL;
                        // Link local address is FE80::1
-                       memset(&req.lladdr6, 0, sizeof(req.lladdr6));
-                       req.lladdr6.s6_addr[0] = 0xFE;
-                       req.lladdr6.s6_addr[1] = 0x80;
-                       req.lladdr6.s6_addr[15] = 1;
+                       memset(&ipv6_attr.addr6, 0, sizeof(ipv6_attr.addr6));
+                       ipv6_attr.addr6.s6_addr[0] = 0xFE;
+                       ipv6_attr.addr6.s6_addr[1] = 0x80;
+                       ipv6_attr.addr6.s6_addr[15] = 1;
+                       memcpy(NLMSG_DATA(&req.nh) + sizeof(req.ifmsg.ifaddr), &ipv6_attr, sizeof(ipv6_attr));
+
+                       req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr)
+                                       + ipv6_attr.rta.rta_len);
 
-                       req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
-                                       + req.lladdr6_rta.rta_len);
+                       if (netlink_send(&req.nh, 1) < 0)
+                       {
+                               LOG(0, 0, 0, "Error setting up tun device IPv6 LL address: %s\n", strerror(errno));
+                               exit(1);
+                       }
 
-                       req.addr6_nh.nlmsg_type = RTM_NEWADDR;
-                       req.addr6_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+                       memset(&req, 0, sizeof(req));
 
-                       req.ifaddr6.ifa_family = AF_INET6;
-                       req.ifaddr6.ifa_prefixlen = 64;
-                       req.ifaddr6.ifa_scope = RT_SCOPE_UNIVERSE;
-                       req.ifaddr6.ifa_index = ifinfo.ifi_index;
+                       req.nh.nlmsg_type = RTM_NEWADDR;
+                       req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
 
-                       req.addr6_rta.rta_len = RTA_LENGTH(sizeof(req.addr6));
-                       req.addr6_rta.rta_type = IFA_LOCAL;
+                       req.ifmsg.ifaddr.ifa_family = AF_INET6;
+                       req.ifmsg.ifaddr.ifa_prefixlen = 64;
+                       req.ifmsg.ifaddr.ifa_scope = RT_SCOPE_UNIVERSE;
+                       req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
+
+                       ipv6_attr.rta.rta_len = RTA_LENGTH(sizeof(ipv6_attr.addr6));
+                       ipv6_attr.rta.rta_type = IFA_LOCAL;
                        // Global address is prefix::1
-                       req.addr6 = config->ipv6_prefix;
-                       req.addr6.s6_addr[15] = 1;
+                       ipv6_attr.addr6 = config->ipv6_prefix;
+                       ipv6_attr.addr6.s6_addr[15] = 1;
+                       memcpy(NLMSG_DATA(&req.nh) + sizeof(req.ifmsg.ifaddr), &ipv6_attr, sizeof(ipv6_attr));
 
-                       req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
-                                       + req.lladdr6_rta.rta_len);
+                       req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr)
+                                       + ipv6_attr.rta.rta_len);
 
-                       req.end_nh.nlmsg_type = NLMSG_DONE;
-                       req.end_nh.nlmsg_len = NLMSG_LENGTH(0);
-               }
-               else
-               {
-                       // we terminate at the beginning of IPv6 stuff
-                       req.lladdr6_nh.nlmsg_type = NLMSG_DONE;
-                       req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(0);
+                       if (netlink_send(&req.nh, 1) < 0)
+                       {
+                               LOG(0, 0, 0, "Error setting up tun device IPv6 global address: %s\n", strerror(errno));
+                               exit(1);
+                       }
+
+                       memset(&req, 0, sizeof(req));
                }
 
+               req.nh.nlmsg_type = NLMSG_DONE;
+               req.nh.nlmsg_len = NLMSG_LENGTH(0);
+
                if (netlink_send(&req.nh, 1) < 0)
                {
-                       LOG(0, 0, 0, "Error setting up tun device: %s\n", strerror(errno));
+                       LOG(0, 0, 0, "Error finishing setting up tun device: %s\n", strerror(errno));
                        exit(1);
                }
 
-               if (netlink_recv(buf, sizeof(buf)) < 0)
+               buf_ptr = buf;
+               buf_len = sizeof(buf);
+               do
                {
-                       LOG(0, 0, 0, "Error waiting ack for setting up tun device: %s\n", strerror(errno));
-                       exit(1);
+                       len = netlink_recv(buf_ptr, sizeof(buf_len));
+                       if (len < 0)
+                       {
+                               LOG(0, 0, 0, "Error waiting for ack setting up tun device: %s\n", strerror(errno));
+                               exit(1);
+                       }
+
+                       resp_nh = (struct nlmsghdr *)buf_ptr;
+                       buf_len -= len;
+                       buf_ptr += len;
                }
+               while (buf_len > 0 && (resp_nh->nlmsg_flags & NLM_F_MULTI)
+                               && resp_nh->nlmsg_type != NLMSG_DONE);
 
-               if ((err = netlink_check_ack((struct nlmsghdr *)buf, 4)))
+               if ((err = netlink_check_ack((struct nlmsghdr *)buf, buf_len, 4)))
                {
                        if (err < 0)
                                LOG(0, 0, 0, "Error while receiving tun device ack: %s\n", strerror(errno));