nss-myhostname: move local address listing logic into shared, so that we can make use of it from machined

1 files changed, 150 insertions, 0 deletions

diff --git a/src/libsystemd/sd-rtnl/local-addresses.c b/src/libsystemd/sd-rtnl/local-addresses.c
new file mode 100644
index 0000000000..dd5ccedc9d
--- /dev/null
+++ b/src/libsystemd/sd-rtnl/local-addresses.c
@@ -0,0 +1,150 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2008-2011 Lennart Poettering
+  Copyright 2014 Tom Gundersen
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-rtnl.h"
+#include "rtnl-util.h"
+#include "macro.h"
+#include "local-addresses.h"
+
+static int address_compare(const void *_a, const void *_b) {
+        const struct local_address *a = _a, *b = _b;
+
+        /* Order lowest scope first, IPv4 before IPv6, lowest interface index first */
+
+        if (a->scope < b->scope)
+                return -1;
+        if (a->scope > b->scope)
+                return 1;
+
+        if (a->family == AF_INET && b->family == AF_INET6)
+                return -1;
+        if (a->family == AF_INET6 && b->family == AF_INET)
+                return 1;
+
+        if (a->ifindex < b->ifindex)
+                return -1;
+        if (a->ifindex > b->ifindex)
+                return 1;
+
+        return 0;
+}
+
+int local_addresses(struct local_address **ret) {
+        _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
+        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+        _cleanup_free_ struct local_address *list = NULL;
+        size_t n_list = 0, n_allocated = 0;
+        sd_rtnl_message *m;
+        int r;
+
+        assert(ret);
+
+        r = sd_rtnl_open(&rtnl, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_message_new_addr(rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_call(rtnl, req, 0, &reply);
+        if (r < 0)
+                return r;
+
+        for (m = reply; m; m = sd_rtnl_message_next(m)) {
+                struct local_address *a;
+                unsigned char flags;
+                uint16_t type;
+
+                r = sd_rtnl_message_get_errno(m);
+                if (r < 0)
+                        return r;
+
+                r = sd_rtnl_message_get_type(m, &type);
+                if (r < 0)
+                        return r;
+
+                if (type != RTM_NEWADDR)
+                        continue;
+
+                r = sd_rtnl_message_addr_get_flags(m, &flags);
+                if (r < 0)
+                        return r;
+
+                if (flags & IFA_F_DEPRECATED)
+                        continue;
+
+                if (!GREEDY_REALLOC(list, n_allocated, n_list+1))
+                        return -ENOMEM;
+
+                a = list + n_list;
+
+                r = sd_rtnl_message_addr_get_scope(m, &a->scope);
+                if (r < 0)
+                        return r;
+
+                if (a->scope == RT_SCOPE_HOST || a->scope == RT_SCOPE_NOWHERE)
+                        continue;
+
+                r = sd_rtnl_message_addr_get_family(m, &a->family);
+                if (r < 0)
+                        return r;
+
+                switch (a->family) {
+
+                case AF_INET:
+                        r = sd_rtnl_message_read_in_addr(m, IFA_LOCAL, &a->address.in);
+                        if (r < 0) {
+                                r = sd_rtnl_message_read_in_addr(m, IFA_ADDRESS, &a->address.in);
+                                if (r < 0)
+                                        continue;
+                        }
+                        break;
+
+                case AF_INET6:
+                        r = sd_rtnl_message_read_in6_addr(m, IFA_LOCAL, &a->address.in6);
+                        if (r < 0) {
+                                r = sd_rtnl_message_read_in6_addr(m, IFA_ADDRESS, &a->address.in6);
+                                if (r < 0)
+                                        continue;
+                        }
+                        break;
+
+                default:
+                        continue;
+                }
+
+                r = sd_rtnl_message_addr_get_ifindex(m, &a->ifindex);
+                if (r < 0)
+                        return r;
+
+                n_list++;
+        };
+
+        if (n_list)
+                qsort(list, n_list, sizeof(struct local_address), address_compare);
+
+        *ret = list;
+        list = NULL;
+
+        return (int) n_list;
+}