ldpd: do a full configuration reload upon receiving a SIGHUP

The rationale here is to do something very similar to what the original
OpenBSD's ldpd(8) does to reload configuration files:
* create a new empty base configuration (vty_conf);
* parse the configuration file and store the result in vty_conf;
* merge the new configuration into the current configuration.

To do this, introduce a new global variable called "sighup" so that ldpd
doesn't attempt to merge vty_conf into ldpd_conf for each command in
the configuration file, which would be very disruptive. vty_conf should
be merged only after the whole configuration file is parsed in order to
avoid taking actions like shutting down neighbors when not necessary.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

diff --git a/ldpd/ldp_vty_conf.c b/ldpd/ldp_vty_conf.c
index 68e3a3601389dad6308ddedacb9cf6136866fcfe..f2b7d6f366cc0a54fa125369198eb938a44539a6 100644 (file)
--- a/ldpd/ldp_vty_conf.c
+++ b/ldpd/ldp_vty_conf.c
@@ -37,11 +37,17 @@ static void  ldp_af_iface_config_write(struct vty *, int);
 static void     ldp_af_config_write(struct vty *, int, struct ldpd_conf *,
                    struct ldpd_af_conf *);
 static void     ldp_l2vpn_pw_config_write(struct vty *, struct l2vpn_pw *);
+static void     ldp_vty_push_node(struct vty *, int, void *);
+static void    *ldp_vty_get_node(struct vty *, void *, int);
 static int      ldp_vty_get_af(struct vty *);
 static int      ldp_iface_is_configured(struct ldpd_conf *, const char *);
 static int      ldp_vty_nbr_session_holdtime(struct vty *, struct vty_arg *[]);
 static int      ldp_vty_af_session_holdtime(struct vty *, struct vty_arg *[]);
 
+static struct iface    *vty_iface;
+static struct l2vpn    *vty_l2vpn;
+static struct l2vpn_pw *vty_pw;
+
 static struct cmd_node interface_node =
 {
        INTERFACE_NODE,
@@ -413,6 +419,94 @@ ldp_l2vpn_config_write(struct vty *vty)
        return (0);
 }
 
+void
+ldp_vty_push_node(struct vty *vty, int node, void *ptr)
+{
+       if (global.sighup) {
+               switch (node) {
+               case LDP_IPV4_IFACE_NODE:
+               case LDP_IPV6_IFACE_NODE:
+                       vty_iface = ptr;
+                       break;
+               case LDP_L2VPN_NODE:
+                       vty_l2vpn = ptr;
+                       break;
+               case LDP_PSEUDOWIRE_NODE:
+                       vty_pw = ptr;
+                       break;
+               default:
+                       fatalx("ldp_vty_push_node: unexpected node");
+               }
+               vty->node = node;
+               return;
+       }
+
+       switch (node) {
+       case LDP_IPV4_IFACE_NODE:
+       case LDP_IPV6_IFACE_NODE:
+               VTY_PUSH_CONTEXT(node, (struct iface *)ptr);
+               break;
+       case LDP_L2VPN_NODE:
+               VTY_PUSH_CONTEXT(node, (struct l2vpn *)ptr);
+               break;
+       case LDP_PSEUDOWIRE_NODE:
+               VTY_PUSH_CONTEXT_SUB(node, (struct l2vpn_pw *)ptr);
+               break;
+       default:
+               fatalx("ldp_vty_push_node: unexpected node");
+       }
+}
+
+void *
+ldp_vty_get_node(struct vty *vty, void *parent, int node)
+{
+       struct iface            *iface;
+       struct l2vpn            *l2vpn;
+       struct l2vpn_pw         *pw;
+
+       if (global.sighup) {
+               switch (node) {
+               case LDP_IPV4_IFACE_NODE:
+               case LDP_IPV6_IFACE_NODE:
+                       return (vty_iface);
+               case LDP_L2VPN_NODE:
+                       return (vty_l2vpn);
+               case LDP_PSEUDOWIRE_NODE:
+                       return (vty_pw);
+               default:
+                       fatalx("ldp_vty_get_node: unexpected node");
+               }
+       }
+
+       /*
+        * Since VTY_GET_CONTEXT() returns a pointer to an element of ldpd_conf,
+        * we have to find the equivalent element inside vty_conf (which should
+        * always exist as vty_conf is a duplicate of ldpd_conf).
+        */
+       switch (node) {
+       case LDP_IPV4_IFACE_NODE:
+       case LDP_IPV6_IFACE_NODE:
+               iface = VTY_GET_CONTEXT(iface);
+               if (iface)
+                       return (if_lookup_name(vty_conf, iface->name));
+               break;
+       case LDP_L2VPN_NODE:
+               l2vpn = VTY_GET_CONTEXT(l2vpn);
+               if (l2vpn)
+                       return (l2vpn_find(vty_conf, l2vpn->name));
+               break;
+       case LDP_PSEUDOWIRE_NODE:
+               pw = VTY_GET_CONTEXT_SUB(l2vpn_pw);
+               if (pw)
+                       return (l2vpn_pw_find_name(parent, pw->ifname));
+               break;
+       default:
+               fatalx("ldp_vty_get_node: unexpected node");
+       }
+
+       return (NULL);
+}
+
 static int
 ldp_vty_get_af(struct vty *vty)
 {
@@ -590,7 +684,8 @@ ldp_vty_disc_holdtime(struct vty *vty, struct vty_arg *args[])
        case LDP_IPV4_IFACE_NODE:
        case LDP_IPV6_IFACE_NODE:
                af = ldp_vty_get_af(vty);
-               iface = VTY_GET_CONTEXT(iface);
+               iface = ldp_vty_get_node(vty, NULL, vty->node);
+               VTY_CHECK_CONTEXT(iface);
 
                ia = iface_af_get(iface, af);
                if (disable)
@@ -689,7 +784,8 @@ ldp_vty_disc_interval(struct vty *vty, struct vty_arg *args[])
        case LDP_IPV4_IFACE_NODE:
        case LDP_IPV6_IFACE_NODE:
                af = ldp_vty_get_af(vty);
-               iface = VTY_GET_CONTEXT(iface);
+               iface = ldp_vty_get_node(vty, NULL, vty->node);
+               VTY_CHECK_CONTEXT(iface);
 
                ia = iface_af_get(iface, af);
                if (disable)
@@ -898,10 +994,10 @@ ldp_vty_interface(struct vty *vty, struct vty_arg *args[])
 
        switch (af) {
        case AF_INET:
-               VTY_PUSH_CONTEXT(LDP_IPV4_IFACE_NODE, iface);
+               ldp_vty_push_node(vty, LDP_IPV4_IFACE_NODE, iface);
                break;
        case AF_INET6:
-               VTY_PUSH_CONTEXT(LDP_IPV6_IFACE_NODE, iface);
+               ldp_vty_push_node(vty, LDP_IPV6_IFACE_NODE, iface);
                break;
        default:
                break;
@@ -1335,7 +1431,7 @@ ldp_vty_l2vpn(struct vty *vty, struct vty_arg *args[])
        }
 
        if (l2vpn) {
-               VTY_PUSH_CONTEXT(LDP_L2VPN_NODE, l2vpn);
+               ldp_vty_push_node(vty, LDP_L2VPN_NODE, l2vpn);
                return (CMD_SUCCESS);
        }
 
@@ -1344,7 +1440,7 @@ ldp_vty_l2vpn(struct vty *vty, struct vty_arg *args[])
        RB_INSERT(l2vpn_head, &vty_conf->l2vpn_tree, l2vpn);
 
        ldp_reload(vty_conf);
-       VTY_PUSH_CONTEXT(LDP_L2VPN_NODE, l2vpn);
+       ldp_vty_push_node(vty, LDP_L2VPN_NODE, l2vpn);
 
        return (CMD_SUCCESS);
 }
@@ -1359,8 +1455,8 @@ ldp_vty_l2vpn_bridge(struct vty *vty, struct vty_arg *args[])
        disable = (vty_get_arg_value(args, "no")) ? 1 : 0;
        ifname = vty_get_arg_value(args, "ifname");
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
 
        if (disable)
                memset(l2vpn->br_ifname, 0, sizeof(l2vpn->br_ifname));
@@ -1390,8 +1486,8 @@ ldp_vty_l2vpn_mtu(struct vty *vty, struct vty_arg *args[])
                return (CMD_WARNING);
        }
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
 
        if (disable)
                l2vpn->mtu = DEFAULT_L2VPN_MTU;
@@ -1419,8 +1515,8 @@ ldp_vty_l2vpn_pwtype(struct vty *vty, struct vty_arg *args[])
        else
                pw_type = PW_TYPE_ETHERNET_TAGGED;
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
 
        if (disable)
                l2vpn->pw_type = DEFAULT_PW_TYPE;
@@ -1445,8 +1541,8 @@ ldp_vty_l2vpn_interface(struct vty *vty, struct vty_arg *args[])
        disable = (vty_get_arg_value(args, "no")) ? 1 : 0;
        ifname = vty_get_arg_value(args, "ifname");
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
        lif = l2vpn_if_find_name(l2vpn, ifname);
 
        if (disable) {
@@ -1496,8 +1592,8 @@ ldp_vty_l2vpn_pseudowire(struct vty *vty, struct vty_arg *args[])
        disable = (vty_get_arg_value(args, "no")) ? 1 : 0;
        ifname = vty_get_arg_value(args, "ifname");
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
        pw = l2vpn_pw_find_name(l2vpn, ifname);
 
        if (disable) {
@@ -1511,7 +1607,7 @@ ldp_vty_l2vpn_pseudowire(struct vty *vty, struct vty_arg *args[])
        }
 
        if (pw) {
-               VTY_PUSH_CONTEXT_SUB(LDP_PSEUDOWIRE_NODE, pw);
+               ldp_vty_push_node(vty, LDP_PSEUDOWIRE_NODE, pw);
                return (CMD_SUCCESS);
        }
 
@@ -1533,7 +1629,7 @@ ldp_vty_l2vpn_pseudowire(struct vty *vty, struct vty_arg *args[])
        RB_INSERT(l2vpn_pw_head, &l2vpn->pw_inactive_tree, pw);
 
        ldp_reload(vty_conf);
-       VTY_PUSH_CONTEXT_SUB(LDP_PSEUDOWIRE_NODE, pw);
+       ldp_vty_push_node(vty, LDP_PSEUDOWIRE_NODE, pw);
 
        return (CMD_SUCCESS);
 }
@@ -1549,10 +1645,10 @@ ldp_vty_l2vpn_pw_cword(struct vty *vty, struct vty_arg *args[])
        disable = (vty_get_arg_value(args, "no")) ? 1 : 0;
        preference_str = vty_get_arg_value(args, "preference");
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
-       pw = VTY_GET_CONTEXT_SUB(l2vpn_pw);
-       pw = l2vpn_pw_find_name(l2vpn, pw->ifname);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
+       pw = ldp_vty_get_node(vty, l2vpn, LDP_PSEUDOWIRE_NODE);
+       VTY_CHECK_CONTEXT(pw);
 
        if (disable)
                pw->flags |= F_PW_CWORD_CONF;
@@ -1587,10 +1683,10 @@ ldp_vty_l2vpn_pw_nbr_addr(struct vty *vty, struct vty_arg *args[])
                return (CMD_WARNING);
        }
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
-       pw = VTY_GET_CONTEXT_SUB(l2vpn_pw);
-       pw = l2vpn_pw_find_name(l2vpn, pw->ifname);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
+       pw = ldp_vty_get_node(vty, l2vpn, LDP_PSEUDOWIRE_NODE);
+       VTY_CHECK_CONTEXT(pw);
 
        if (disable) {
                pw->af = AF_UNSPEC;
@@ -1625,10 +1721,10 @@ ldp_vty_l2vpn_pw_nbr_id(struct vty *vty, struct vty_arg *args[])
                return (CMD_WARNING);
        }
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
-       pw = VTY_GET_CONTEXT_SUB(l2vpn_pw);
-       pw = l2vpn_pw_find_name(l2vpn, pw->ifname);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
+       pw = ldp_vty_get_node(vty, l2vpn, LDP_PSEUDOWIRE_NODE);
+       VTY_CHECK_CONTEXT(pw);
 
        if (disable)
                pw->lsr_id.s_addr = INADDR_ANY;
@@ -1659,10 +1755,10 @@ ldp_vty_l2vpn_pw_pwid(struct vty *vty, struct vty_arg *args[])
                return (CMD_WARNING);
        }
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
-       pw = VTY_GET_CONTEXT_SUB(l2vpn_pw);
-       pw = l2vpn_pw_find_name(l2vpn, pw->ifname);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
+       pw = ldp_vty_get_node(vty, l2vpn, LDP_PSEUDOWIRE_NODE);
+       VTY_CHECK_CONTEXT(pw);
 
        if (disable)
                pw->pwid = 0;
@@ -1683,10 +1779,10 @@ ldp_vty_l2vpn_pw_pwstatus(struct vty *vty, struct vty_arg *args[])
 
        disable = (vty_get_arg_value(args, "no")) ? 1 : 0;
 
-       l2vpn = VTY_GET_CONTEXT(l2vpn);
-       l2vpn = l2vpn_find(vty_conf, l2vpn->name);
-       pw = VTY_GET_CONTEXT_SUB(l2vpn_pw);
-       pw = l2vpn_pw_find_name(l2vpn, pw->ifname);
+       l2vpn = ldp_vty_get_node(vty, NULL, LDP_L2VPN_NODE);
+       VTY_CHECK_CONTEXT(l2vpn);
+       pw = ldp_vty_get_node(vty, l2vpn, LDP_PSEUDOWIRE_NODE);
+       VTY_CHECK_CONTEXT(pw);
 
        if (disable)
                pw->flags |= F_PW_STATUSTLV_CONF;

diff --git a/ldpd/ldpd.c b/ldpd/ldpd.c
index c3d72d022a600a756520d5fb769c0fc7d7236c9f..96ae5ad879fa9aec4461780f57cc35e35de5b7fc 100644 (file)
--- a/ldpd/ldpd.c
+++ b/ldpd/ldpd.c
@@ -89,6 +89,8 @@ static pid_t           lde_pid;
 /* Master of threads. */
 struct thread_master *master;
 
+static struct frr_daemon_info ldpd_di;
+
 /* ldpd privileges */
 static zebra_capabilities_t _caps_p [] =
 {
@@ -127,6 +129,22 @@ static void
 sighup(void)
 {
        log_info("SIGHUP received");
+
+       /* reset vty_conf */
+       ldp_clear_config(vty_conf);
+       vty_conf = config_new_empty();
+       ldp_config_reset_main(vty_conf);
+
+       /* read configuration file without applying any changes */
+       global.sighup = 1;
+       vty_read_config(ldpd_di.config_file, config_default);
+       global.sighup = 0;
+
+       /*
+        * Apply the new configuration all at once, this way merge_config()
+        * will be the least disruptive as possible.
+        */
+       ldp_reload(vty_conf);
 }
 
 /* SIGINT / SIGTERM handler. */
@@ -965,6 +983,9 @@ main_imsg_send_config(struct ldpd_conf *xconf)
 int
 ldp_reload(struct ldpd_conf *xconf)
 {
+       if (global.sighup)
+               return (0);
+
        ldp_config_normalize(xconf);
 
        if (main_imsg_send_config(xconf) == -1)

diff --git a/ldpd/ldpd.h b/ldpd/ldpd.h
index 69235556f8f674094b46e357d0473aac806c2dc2..a0474a5a2dae862724f0b90b66983ea46bbcf3d0 100644 (file)
--- a/ldpd/ldpd.h
+++ b/ldpd/ldpd.h
@@ -503,6 +503,7 @@ struct ldpd_af_global {
 
 struct ldpd_global {
        int                      cmd_opts;
+       int                      sighup;
        time_t                   uptime;
        struct in_addr           rtr_id;
        struct ldpd_af_global    ipv4;