inet_diag: factor out prep code

We're going to experiment with something...

1 files changed, 64 insertions, 41 deletions

diff --git a/ext/raindrops/linux_inet_diag.c b/ext/raindrops/linux_inet_diag.c
index 9e42c64..8feded5 100644
--- a/ext/raindrops/linux_inet_diag.c
+++ b/ext/raindrops/linux_inet_diag.c
@@ -108,70 +108,93 @@ static const char err_sendmsg[] = "sendmsg";
 static const char err_recvmsg[] = "recvmsg";
 static const char err_nlmsg[] = "nlmsg";
 
+struct diag_req {
+        struct nlmsghdr nlh;
+        struct inet_diag_req r;
+};
+
+static void prep_msghdr(
+        struct msghdr *msg,
+        struct nogvl_args *args,
+        struct sockaddr_nl *nladdr)
+{
+        memset(msg, 0, sizeof(struct msghdr));
+        msg->msg_name = (void *)nladdr;
+        msg->msg_namelen = sizeof(struct sockaddr_nl);
+        msg->msg_iov = args->iov;
+        msg->msg_iovlen = 3;
+}
+
+static void prep_diag_args(
+        struct nogvl_args *args,
+        struct sockaddr_nl *nladdr,
+        struct rtattr *rta,
+        struct diag_req *req,
+        struct msghdr *msg)
+{
+        memset(&args->stats, 0, sizeof(struct listen_stats));
+        memset(req, 0, sizeof(struct diag_req));
+        memset(nladdr, 0, sizeof(struct sockaddr_nl));
+
+        nladdr->nl_family = AF_NETLINK;
+
+        req->nlh.nlmsg_len = sizeof(struct diag_req) +
+                            RTA_LENGTH(args->iov[2].iov_len);
+        req->nlh.nlmsg_type = TCPDIAG_GETSOCK;
+        req->nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
+        req->nlh.nlmsg_pid = getpid();
+        req->r.idiag_states = (1<<TCP_ESTABLISHED) | (1<<TCP_LISTEN);
+        rta->rta_type = INET_DIAG_REQ_BYTECODE;
+        rta->rta_len = RTA_LENGTH(args->iov[2].iov_len);
+
+        args->iov[0].iov_base = req;
+        args->iov[0].iov_len = sizeof(struct diag_req);
+        args->iov[1].iov_base = rta;
+        args->iov[1].iov_len = sizeof(struct rtattr);
+
+        prep_msghdr(msg, args, nladdr);
+}
+
+static void prep_recvmsg_buf(struct nogvl_args *args)
+{
+        /* reuse buffer that was allocated for bytecode */
+        args->iov[0].iov_len = page_size;
+        args->iov[0].iov_base = args->iov[2].iov_base;
+}
+
 /* does the inet_diag stuff with netlink(), this is called w/o GVL */
 static VALUE diag(void *ptr)
 {
+        struct inet_diag_bc_op *op;
+        struct inet_diag_hostcond *cond;
         struct nogvl_args *args = ptr;
         struct sockaddr_nl nladdr;
         struct rtattr rta;
-        struct {
-                struct nlmsghdr nlh;
-                struct inet_diag_req r;
-        } req;
+        struct diag_req req;
         struct msghdr msg;
         const char *err = NULL;
-        unsigned seq = ++g_seq; /* not atomic, rely on GVL for now */
+        unsigned seq = ++g_seq;
         int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_INET_DIAG);
 
         if (fd < 0)
                 return (VALUE)err_socket;
 
-        memset(&args->stats, 0, sizeof(struct listen_stats));
-
-        memset(&nladdr, 0, sizeof(nladdr));
-        nladdr.nl_family = AF_NETLINK;
-
-        memset(&req, 0, sizeof(req));
-        req.nlh.nlmsg_len = sizeof(req) + RTA_LENGTH(args->iov[2].iov_len);
-        req.nlh.nlmsg_type = TCPDIAG_GETSOCK;
-        req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
-        req.nlh.nlmsg_pid = getpid();
+        prep_diag_args(args, &nladdr, &rta, &req, &msg);
+        op = args->iov->iov_base;
+        cond = (struct inet_diag_hostcond *)(op + 1);
+        req.r.idiag_family = cond->family;
         req.nlh.nlmsg_seq = seq;
-        req.r.idiag_family = AF_INET | AF_INET6;
-        req.r.idiag_states = (1<<TCP_ESTABLISHED) | (1<<TCP_LISTEN);
-        rta.rta_type = INET_DIAG_REQ_BYTECODE;
-        rta.rta_len = RTA_LENGTH(args->iov[2].iov_len);
-
-        args->iov[0].iov_base = &req;
-        args->iov[0].iov_len = sizeof(req);
-        args->iov[1].iov_base = &rta;
-        args->iov[1].iov_len = sizeof(rta);
-
-        memset(&msg, 0, sizeof(msg));
-        msg.msg_name = (void *)&nladdr;
-        msg.msg_namelen = sizeof(nladdr);
-        msg.msg_iov = args->iov;
-        msg.msg_iovlen = 3;
-
         if (sendmsg(fd, &msg, 0) < 0) {
                 err = err_sendmsg;
                 goto out;
         }
-
-        /* reuse buffer that was allocated for bytecode */
-        args->iov[0].iov_len = page_size;
-        args->iov[0].iov_base = args->iov[2].iov_base;
+        prep_recvmsg_buf(args);
 
         while (1) {
                 ssize_t readed;
                 struct nlmsghdr *h = (struct nlmsghdr *)args->iov[0].iov_base;
 
-                memset(&msg, 0, sizeof(msg));
-                msg.msg_name = (void *)&nladdr;
-                msg.msg_namelen = sizeof(nladdr);
-                msg.msg_iov = args->iov;
-                msg.msg_iovlen = 1;
-
+                prep_msghdr(&msg, args, &nladdr);
                 readed = recvmsg(fd, &msg, 0);
                 if (readed < 0) {
                         if (errno == EINTR)