add hostsfile output in addition to statefile

[project/odhcpd.git] / src / dhcpv6-ia.c

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 41c9f30fbcc9cb6c7e9cba895626a035569cd4d3..1fbed44e0555d496a638ab6a4db95139605050cd 100644 (file)
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -288,6 +288,26 @@ struct write_ctxt {
        int buf_idx;
 };
 
+static void dhcpv6_write_ia_addrhosts(struct in6_addr *addr, int prefix, _unused uint32_t pref,
+                               _unused uint32_t valid, void *arg)
+{
+       struct write_ctxt *ctxt = (struct write_ctxt *)arg;
+       char ipbuf[INET6_ADDRSTRLEN];
+
+       if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
+           !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
+               inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
+               fputs(ipbuf, ctxt->fp);
+
+               char b[256];
+               if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
+                               ctxt->iface->search, b, sizeof(b)) > 0)
+                       fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
+
+               fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
+       }
+}
+
 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
                                _unused uint32_t valid, void *arg)
 {
@@ -314,6 +334,98 @@ static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint
                                        "%s/%d ", ipbuf, prefix);
 }
 
+static void dhcpv6_ia_write_hostsfile(time_t now)
+{
+       struct write_ctxt ctxt;
+
+       unsigned hostsfile_strlen = strlen(config.dhcp_hostsfile) + 1;
+       unsigned tmp_hostsfile_strlen = hostsfile_strlen + 1; /* space for . */
+       char *tmp_hostsfile = alloca(tmp_hostsfile_strlen);
+
+       char *dir_hostsfile;
+       char *base_hostsfile;
+       char *pdir_hostsfile;
+       char *pbase_hostsfile;
+
+       int fd, ret;
+
+       dir_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
+       base_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
+
+       pdir_hostsfile = dirname(dir_hostsfile);
+       pbase_hostsfile = basename(base_hostsfile);
+
+       snprintf(tmp_hostsfile, tmp_hostsfile_strlen, "%s/.%s", pdir_hostsfile, pbase_hostsfile);
+
+       free(dir_hostsfile);
+       free(base_hostsfile);
+
+       fd = open(tmp_hostsfile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
+       if (fd < 0)
+               return;
+
+       ret = lockf(fd, F_LOCK, 0);
+       if (ret < 0) {
+               close(fd);
+               return;
+       }
+
+       if (ftruncate(fd, 0) < 0) {}
+
+       ctxt.fp = fdopen(fd, "w");
+       if (!ctxt.fp) {
+               close(fd);
+               return;
+       }
+
+       avl_for_each_element(&interfaces, ctxt.iface, avl) {
+               if (ctxt.iface->dhcpv6 != MODE_SERVER &&
+                               ctxt.iface->dhcpv4 != MODE_SERVER)
+                       continue;
+
+               if (ctxt.iface->dhcpv6 == MODE_SERVER) {
+                       list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
+                               if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
+                                       continue;
+
+                               if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
+                                       dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
+                                                               dhcpv6_write_ia_addrhosts, &ctxt);
+                       }
+               }
+
+               if (ctxt.iface->dhcpv4 == MODE_SERVER) {
+                       struct dhcp_assignment *c;
+
+                       list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
+                               if (!(c->flags & OAF_BOUND))
+                                       continue;
+
+                               char ipbuf[INET6_ADDRSTRLEN];
+                               struct in_addr addr = {.s_addr = c->addr};
+                               inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
+
+                               if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
+                                       fputs(ipbuf, ctxt.fp);
+
+                                       char b[256];
+
+                                       if (dn_expand(ctxt.iface->search,
+                                                       ctxt.iface->search + ctxt.iface->search_len,
+                                                       ctxt.iface->search, b, sizeof(b)) > 0)
+                                               fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
+
+                                       fprintf(ctxt.fp, "\t%s\n", c->hostname);
+                               }
+                       }
+               }
+       }
+
+       fclose(ctxt.fp);
+
+       rename(tmp_hostsfile, config.dhcp_hostsfile);
+}
+
 void dhcpv6_ia_write_statefile(void)
 {
        struct write_ctxt ctxt;
@@ -457,9 +569,13 @@ void dhcpv6_ia_write_statefile(void)
                uint8_t newmd5[16];
                md5_end(newmd5, &ctxt.md5);
 
+               rename(tmp_statefile, config.dhcp_statefile);
+
                if (memcmp(newmd5, statemd5, sizeof(newmd5))) {
                        memcpy(statemd5, newmd5, sizeof(statemd5));
-                       rename(tmp_statefile, config.dhcp_statefile);
+
+                       if (config.dhcp_hostsfile)
+                               dhcpv6_ia_write_hostsfile(now);
 
                        if (config.dhcp_cb) {
                                char *argv[2] = {config.dhcp_cb, NULL};
@@ -468,8 +584,6 @@ void dhcpv6_ia_write_statefile(void)
                                        _exit(128);
                                }
                        }
-               } else {
-                       unlink(tmp_statefile);
                }
        }
 }