./tools/notsd-move

5 files changed, 861 insertions, 0 deletions

diff --git a/src/grp-resolve/nss-resolve/GNUmakefile b/src/grp-resolve/nss-resolve/GNUmakefile
new file mode 120000
index 0000000000..95e5924740
--- /dev/null
+++ b/src/grp-resolve/nss-resolve/GNUmakefile
@@ -0,0 +1 @@
+../../../GNUmakefile
\ No newline at end of file
diff --git a/src/grp-resolve/nss-resolve/Makefile b/src/grp-resolve/nss-resolve/Makefile
new file mode 100644
index 0000000000..310f816b06
--- /dev/null
+++ b/src/grp-resolve/nss-resolve/Makefile
@@ -0,0 +1,46 @@
+#  -*- Mode: makefile; indent-tabs-mode: t -*-
+#
+#  This file is part of systemd.
+#
+#  Copyright 2010-2012 Lennart Poettering
+#  Copyright 2010-2012 Kay Sievers
+#  Copyright 2013 Zbigniew Jędrzejewski-Szmek
+#  Copyright 2013 David Strauss
+#  Copyright 2016 Luke Shumaker
+#
+#  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 $(dir $(lastword $(MAKEFILE_LIST)))/../../../config.mk
+include $(topsrcdir)/build-aux/Makefile.head.mk
+
+libnss_resolve_la_SOURCES = \
+	src/nss-resolve/nss-resolve.sym \
+	src/nss-resolve/nss-resolve.c
+
+libnss_resolve_la_LDFLAGS = \
+	-module \
+	-export-dynamic \
+	-avoid-version \
+	-shared \
+	-shrext .so.2 \
+	-Wl,--version-script=$(srcdir)/nss-resolve.sym
+
+libnss_resolve_la_LIBADD = \
+	libsystemd-internal.la \
+	libsystemd-basic.la \
+        -ldl
+
+rootlib_LTLIBRARIES += \
+	libnss_resolve.la
+
+include $(topsrcdir)/build-aux/Makefile.tail.mk
diff --git a/src/grp-resolve/nss-resolve/nss-resolve.c b/src/grp-resolve/nss-resolve/nss-resolve.c
new file mode 100644
index 0000000000..681416e18f
--- /dev/null
+++ b/src/grp-resolve/nss-resolve/nss-resolve.c
@@ -0,0 +1,681 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2014 Lennart Poettering
+
+  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 <dlfcn.h>
+#include <errno.h>
+#include <netdb.h>
+#include <nss.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <systemd/sd-bus.h>
+
+#include "sd-bus/bus-common-errors.h"
+#include "systemd-basic/in-addr-util.h"
+#include "systemd-basic/macro.h"
+#include "systemd-basic/nss-util.h"
+#include "systemd-basic/signal-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/util.h"
+
+NSS_GETHOSTBYNAME_PROTOTYPES(resolve);
+NSS_GETHOSTBYADDR_PROTOTYPES(resolve);
+
+#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC)
+
+typedef void (*voidfunc_t)(void);
+
+static voidfunc_t find_fallback(const char *module, const char *symbol) {
+        void *dl;
+
+        /* Try to find a fallback NSS module symbol */
+
+        dl = dlopen(module, RTLD_LAZY|RTLD_NODELETE);
+        if (!dl)
+                return NULL;
+
+        return dlsym(dl, symbol);
+}
+
+static bool bus_error_shall_fallback(sd_bus_error *e) {
+        return sd_bus_error_has_name(e, SD_BUS_ERROR_SERVICE_UNKNOWN) ||
+               sd_bus_error_has_name(e, SD_BUS_ERROR_NAME_HAS_NO_OWNER) ||
+               sd_bus_error_has_name(e, SD_BUS_ERROR_NO_REPLY) ||
+               sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED);
+}
+
+static int count_addresses(sd_bus_message *m, int af, const char **canonical) {
+        int c = 0, r;
+
+        assert(m);
+        assert(canonical);
+
+        r = sd_bus_message_enter_container(m, 'a', "(iiay)");
+        if (r < 0)
+                return r;
+
+        while ((r = sd_bus_message_enter_container(m, 'r', "iiay")) > 0) {
+                int family, ifindex;
+
+                assert_cc(sizeof(int32_t) == sizeof(int));
+
+                r = sd_bus_message_read(m, "ii", &ifindex, &family);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_skip(m, "ay");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_exit_container(m);
+                if (r < 0)
+                        return r;
+
+                if (af != AF_UNSPEC && family != af)
+                        continue;
+
+                c++;
+        }
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_exit_container(m);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read(m, "s", canonical);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_rewind(m, true);
+        if (r < 0)
+                return r;
+
+        return c;
+}
+
+enum nss_status _nss_resolve_gethostbyname4_r(
+                const char *name,
+                struct gaih_addrtuple **pat,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp) {
+
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        struct gaih_addrtuple *r_tuple, *r_tuple_first = NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        enum nss_status ret = NSS_STATUS_UNAVAIL;
+        const char *canonical = NULL;
+        size_t l, ms, idx;
+        char *r_name;
+        int c, r, i = 0;
+
+        BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+        assert(name);
+        assert(pat);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
+
+        r = sd_bus_open_system(&bus);
+        if (r < 0)
+                goto fallback;
+
+        r = sd_bus_message_new_method_call(
+                        bus,
+                        &req,
+                        "org.freedesktop.resolve1",
+                        "/org/freedesktop/resolve1",
+                        "org.freedesktop.resolve1.Manager",
+                        "ResolveHostname");
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_set_auto_start(req, false);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_append(req, "isit", 0, name, AF_UNSPEC, (uint64_t) 0);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
+        if (r < 0) {
+                if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) {
+                        *errnop = ESRCH;
+                        *h_errnop = HOST_NOT_FOUND;
+                        return NSS_STATUS_NOTFOUND;
+                }
+
+                if (bus_error_shall_fallback(&error))
+                        goto fallback;
+
+                /* Treat all other error conditions as NOTFOUND, and fail. This includes DNSSEC errors and
+                   suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf configuration can distuingish
+                   such executed but negative replies from complete failure to talk to resolved. */
+                ret = NSS_STATUS_NOTFOUND;
+                goto fail;
+        }
+
+        c = count_addresses(reply, AF_UNSPEC, &canonical);
+        if (c < 0) {
+                r = c;
+                goto fail;
+        }
+        if (c == 0) {
+                *errnop = ESRCH;
+                *h_errnop = HOST_NOT_FOUND;
+                return NSS_STATUS_NOTFOUND;
+        }
+
+        if (isempty(canonical))
+                canonical = name;
+
+        l = strlen(canonical);
+        ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c;
+        if (buflen < ms) {
+                *errnop = ENOMEM;
+                *h_errnop = TRY_AGAIN;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        /* First, append name */
+        r_name = buffer;
+        memcpy(r_name, canonical, l+1);
+        idx = ALIGN(l+1);
+
+        /* Second, append addresses */
+        r_tuple_first = (struct gaih_addrtuple*) (buffer + idx);
+
+        r = sd_bus_message_enter_container(reply, 'a', "(iiay)");
+        if (r < 0)
+                goto fail;
+
+        while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) {
+                int family, ifindex;
+                const void *a;
+                size_t sz;
+
+                assert_cc(sizeof(int32_t) == sizeof(int));
+
+                r = sd_bus_message_read(reply, "ii", &ifindex, &family);
+                if (r < 0)
+                        goto fail;
+
+                if (ifindex < 0) {
+                        r = -EINVAL;
+                        goto fail;
+                }
+
+                r = sd_bus_message_read_array(reply, 'y', &a, &sz);
+                if (r < 0)
+                        goto fail;
+
+                r = sd_bus_message_exit_container(reply);
+                if (r < 0)
+                        goto fail;
+
+                if (!IN_SET(family, AF_INET, AF_INET6))
+                        continue;
+
+                if (sz != FAMILY_ADDRESS_SIZE(family)) {
+                        r = -EINVAL;
+                        goto fail;
+                }
+
+                r_tuple = (struct gaih_addrtuple*) (buffer + idx);
+                r_tuple->next = i == c-1 ? NULL : (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple)));
+                r_tuple->name = r_name;
+                r_tuple->family = family;
+                r_tuple->scopeid = ifindex;
+                memcpy(r_tuple->addr, a, sz);
+
+                idx += ALIGN(sizeof(struct gaih_addrtuple));
+                i++;
+        }
+        if (r < 0)
+                goto fail;
+
+        assert(i == c);
+        assert(idx == ms);
+
+        if (*pat)
+                **pat = *r_tuple_first;
+        else
+                *pat = r_tuple_first;
+
+        if (ttlp)
+                *ttlp = 0;
+
+        /* Explicitly reset all error variables */
+        *errnop = 0;
+        *h_errnop = NETDB_SUCCESS;
+        h_errno = 0;
+
+        return NSS_STATUS_SUCCESS;
+
+fallback:
+        {
+                _nss_gethostbyname4_r_t fallback;
+
+                fallback = (_nss_gethostbyname4_r_t)
+                        find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyname4_r");
+
+                if (fallback)
+                        return fallback(name, pat, buffer, buflen, errnop, h_errnop, ttlp);
+        }
+
+fail:
+        *errnop = -r;
+        *h_errnop = NO_RECOVERY;
+        return ret;
+}
+
+enum nss_status _nss_resolve_gethostbyname3_r(
+                const char *name,
+                int af,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp,
+                char **canonp) {
+
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        char *r_name, *r_aliases, *r_addr, *r_addr_list;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        enum nss_status ret = NSS_STATUS_UNAVAIL;
+        size_t l, idx, ms, alen;
+        const char *canonical;
+        int c, r, i = 0;
+
+        BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+        assert(name);
+        assert(result);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
+
+        if (af == AF_UNSPEC)
+                af = AF_INET;
+
+        if (af != AF_INET && af != AF_INET6) {
+                r = -EAFNOSUPPORT;
+                goto fail;
+        }
+
+        r = sd_bus_open_system(&bus);
+        if (r < 0)
+                goto fallback;
+
+        r = sd_bus_message_new_method_call(
+                        bus,
+                        &req,
+                        "org.freedesktop.resolve1",
+                        "/org/freedesktop/resolve1",
+                        "org.freedesktop.resolve1.Manager",
+                        "ResolveHostname");
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_set_auto_start(req, false);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_append(req, "isit", 0, name, af, (uint64_t) 0);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
+        if (r < 0) {
+                if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) {
+                        *errnop = ESRCH;
+                        *h_errnop = HOST_NOT_FOUND;
+                        return NSS_STATUS_NOTFOUND;
+                }
+
+                if (bus_error_shall_fallback(&error))
+                        goto fallback;
+
+                ret = NSS_STATUS_NOTFOUND;
+                goto fail;
+        }
+
+        c = count_addresses(reply, af, &canonical);
+        if (c < 0) {
+                r = c;
+                goto fail;
+        }
+        if (c == 0) {
+                *errnop = ESRCH;
+                *h_errnop = HOST_NOT_FOUND;
+                return NSS_STATUS_NOTFOUND;
+        }
+
+        if (isempty(canonical))
+                canonical = name;
+
+        alen = FAMILY_ADDRESS_SIZE(af);
+        l = strlen(canonical);
+
+        ms = ALIGN(l+1) + c * ALIGN(alen) + (c+2) * sizeof(char*);
+
+        if (buflen < ms) {
+                *errnop = ENOMEM;
+                *h_errnop = TRY_AGAIN;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        /* First, append name */
+        r_name = buffer;
+        memcpy(r_name, canonical, l+1);
+        idx = ALIGN(l+1);
+
+        /* Second, create empty aliases array */
+        r_aliases = buffer + idx;
+        ((char**) r_aliases)[0] = NULL;
+        idx += sizeof(char*);
+
+        /* Third, append addresses */
+        r_addr = buffer + idx;
+
+        r = sd_bus_message_enter_container(reply, 'a', "(iiay)");
+        if (r < 0)
+                goto fail;
+
+        while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) {
+                int ifindex, family;
+                const void *a;
+                size_t sz;
+
+                r = sd_bus_message_read(reply, "ii", &ifindex, &family);
+                if (r < 0)
+                        goto fail;
+
+                if (ifindex < 0) {
+                        r = -EINVAL;
+                        goto fail;
+                }
+
+                r = sd_bus_message_read_array(reply, 'y', &a, &sz);
+                if (r < 0)
+                        goto fail;
+
+                r = sd_bus_message_exit_container(reply);
+                if (r < 0)
+                        goto fail;
+
+                if (family != af)
+                        continue;
+
+                if (sz != alen) {
+                        r = -EINVAL;
+                        goto fail;
+                }
+
+                memcpy(r_addr + i*ALIGN(alen), a, alen);
+                i++;
+        }
+        if (r < 0)
+                goto fail;
+
+        assert(i == c);
+        idx += c * ALIGN(alen);
+
+        /* Fourth, append address pointer array */
+        r_addr_list = buffer + idx;
+        for (i = 0; i < c; i++)
+                ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen);
+
+        ((char**) r_addr_list)[i] = NULL;
+        idx += (c+1) * sizeof(char*);
+
+        assert(idx == ms);
+
+        result->h_name = r_name;
+        result->h_aliases = (char**) r_aliases;
+        result->h_addrtype = af;
+        result->h_length = alen;
+        result->h_addr_list = (char**) r_addr_list;
+
+        /* Explicitly reset all error variables */
+        *errnop = 0;
+        *h_errnop = NETDB_SUCCESS;
+        h_errno = 0;
+
+        if (ttlp)
+                *ttlp = 0;
+
+        if (canonp)
+                *canonp = r_name;
+
+        return NSS_STATUS_SUCCESS;
+
+fallback:
+        {
+                _nss_gethostbyname3_r_t fallback;
+
+                fallback = (_nss_gethostbyname3_r_t)
+                        find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyname3_r");
+                if (fallback)
+                        return fallback(name, af, result, buffer, buflen, errnop, h_errnop, ttlp, canonp);
+        }
+
+fail:
+        *errnop = -r;
+        *h_errnop = NO_RECOVERY;
+        return ret;
+}
+
+enum nss_status _nss_resolve_gethostbyaddr2_r(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp) {
+
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        char *r_name, *r_aliases, *r_addr, *r_addr_list;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        enum nss_status ret = NSS_STATUS_UNAVAIL;
+        unsigned c = 0, i = 0;
+        size_t ms = 0, idx;
+        const char *n;
+        int r, ifindex;
+
+        BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+        assert(addr);
+        assert(result);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
+
+        if (!IN_SET(af, AF_INET, AF_INET6)) {
+                *errnop = EAFNOSUPPORT;
+                *h_errnop = NO_DATA;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (len != FAMILY_ADDRESS_SIZE(af)) {
+                *errnop = EINVAL;
+                *h_errnop = NO_RECOVERY;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        r = sd_bus_open_system(&bus);
+        if (r < 0)
+                goto fallback;
+
+        r = sd_bus_message_new_method_call(
+                        bus,
+                        &req,
+                        "org.freedesktop.resolve1",
+                        "/org/freedesktop/resolve1",
+                        "org.freedesktop.resolve1.Manager",
+                        "ResolveAddress");
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_set_auto_start(req, false);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_append(req, "ii", 0, af);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_append_array(req, 'y', addr, len);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_append(req, "t", (uint64_t) 0);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply);
+        if (r < 0) {
+                if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) {
+                        *errnop = ESRCH;
+                        *h_errnop = HOST_NOT_FOUND;
+                        return NSS_STATUS_NOTFOUND;
+                }
+
+                if (bus_error_shall_fallback(&error))
+                        goto fallback;
+
+                ret = NSS_STATUS_NOTFOUND;
+                goto fail;
+        }
+
+        r = sd_bus_message_enter_container(reply, 'a', "(is)");
+        if (r < 0)
+                goto fail;
+
+        while ((r = sd_bus_message_read(reply, "(is)", &ifindex, &n)) > 0) {
+
+                if (ifindex < 0) {
+                        r = -EINVAL;
+                        goto fail;
+                }
+
+                c++;
+                ms += ALIGN(strlen(n) + 1);
+        }
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_rewind(reply, false);
+        if (r < 0)
+                return r;
+
+        if (c <= 0) {
+                *errnop = ESRCH;
+                *h_errnop = HOST_NOT_FOUND;
+                return NSS_STATUS_NOTFOUND;
+        }
+
+        ms += ALIGN(len) +              /* the address */
+              2 * sizeof(char*) +       /* pointers to the address, plus trailing NULL */
+              c * sizeof(char*);        /* pointers to aliases, plus trailing NULL */
+
+        if (buflen < ms) {
+                *errnop = ENOMEM;
+                *h_errnop = TRY_AGAIN;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        /* First, place address */
+        r_addr = buffer;
+        memcpy(r_addr, addr, len);
+        idx = ALIGN(len);
+
+        /* Second, place address list */
+        r_addr_list = buffer + idx;
+        ((char**) r_addr_list)[0] = r_addr;
+        ((char**) r_addr_list)[1] = NULL;
+        idx += sizeof(char*) * 2;
+
+        /* Third, reserve space for the aliases array */
+        r_aliases = buffer + idx;
+        idx += sizeof(char*) * c;
+
+        /* Fourth, place aliases */
+        i = 0;
+        r_name = buffer + idx;
+        while ((r = sd_bus_message_read(reply, "(is)", &ifindex, &n)) > 0) {
+                char *p;
+                size_t l;
+
+                l = strlen(n);
+                p = buffer + idx;
+                memcpy(p, n, l+1);
+
+                if (i > 0)
+                        ((char**) r_aliases)[i-1] = p;
+                i++;
+
+                idx += ALIGN(l+1);
+        }
+        if (r < 0)
+                goto fail;
+
+        ((char**) r_aliases)[c-1] = NULL;
+        assert(idx == ms);
+
+        result->h_name = r_name;
+        result->h_aliases = (char**) r_aliases;
+        result->h_addrtype = af;
+        result->h_length = len;
+        result->h_addr_list = (char**) r_addr_list;
+
+        if (ttlp)
+                *ttlp = 0;
+
+        /* Explicitly reset all error variables */
+        *errnop = 0;
+        *h_errnop = NETDB_SUCCESS;
+        h_errno = 0;
+
+        return NSS_STATUS_SUCCESS;
+
+fallback:
+        {
+                _nss_gethostbyaddr2_r_t fallback;
+
+                fallback = (_nss_gethostbyaddr2_r_t)
+                        find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyaddr2_r");
+
+                if (fallback)
+                        return fallback(addr, len, af, result, buffer, buflen, errnop, h_errnop, ttlp);
+        }
+
+fail:
+        *errnop = -r;
+        *h_errnop = NO_RECOVERY;
+        return ret;
+}
+
+NSS_GETHOSTBYNAME_FALLBACKS(resolve);
+NSS_GETHOSTBYADDR_FALLBACKS(resolve);
diff --git a/src/grp-resolve/nss-resolve/nss-resolve.sym b/src/grp-resolve/nss-resolve/nss-resolve.sym
new file mode 100644
index 0000000000..df8dff2a20
--- /dev/null
+++ b/src/grp-resolve/nss-resolve/nss-resolve.sym
@@ -0,0 +1,19 @@
+/***
+  This file is part of systemd.
+
+  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.
+***/
+
+{
+global:
+        _nss_resolve_gethostbyname_r;
+        _nss_resolve_gethostbyname2_r;
+        _nss_resolve_gethostbyname3_r;
+        _nss_resolve_gethostbyname4_r;
+        _nss_resolve_gethostbyaddr_r;
+        _nss_resolve_gethostbyaddr2_r;
+local: *;
+};
diff --git a/src/grp-resolve/nss-resolve/nss-resolve.xml b/src/grp-resolve/nss-resolve/nss-resolve.xml
new file mode 100644
index 0000000000..9f24f65019
--- /dev/null
+++ b/src/grp-resolve/nss-resolve/nss-resolve.xml
@@ -0,0 +1,114 @@
+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+  Copyright 2013 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/>.
+-->
+
+<refentry id="nss-resolve" conditional='ENABLE_RESOLVED'>
+
+  <refentryinfo>
+    <title>nss-resolve</title>
+    <productname>systemd</productname>
+
+    <authorgroup>
+      <author>
+        <contrib>Developer</contrib>
+        <firstname>Lennart</firstname>
+        <surname>Poettering</surname>
+        <email>lennart@poettering.net</email>
+      </author>
+    </authorgroup>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>nss-resolve</refentrytitle>
+    <manvolnum>8</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>nss-resolve</refname>
+    <refname>libnss_resolve.so.2</refname>
+    <refpurpose>Provide hostname resolution via <filename>systemd-resolved.service</filename></refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <para><filename>libnss_resolve.so.2</filename></para>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><command>nss-resolve</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of the
+    GNU C Library (<command>glibc</command>) enabling it to resolve host names via the
+    <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry> local network
+    name resolution service. It replaces the <command>nss-dns</command> plug-in module that traditionally resolves
+    hostnames via DNS.</para>
+
+    <para>To activate the NSS module, add <literal>resolve</literal> to the line starting with
+    <literal>hosts:</literal> in <filename>/etc/nsswitch.conf</filename>.</para>
+
+    <para>It is recommended to place <literal>resolve</literal> early in <filename>/etc/nsswitch.conf</filename>'
+    <literal>hosts:</literal> line (but after the <literal>files</literal> or <literal>mymachines</literal> entries),
+    replacing the <literal>dns</literal> entry if it exists, to ensure DNS queries are always routed via
+    <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
+
+    <para>Note that <command>nss-resolve</command> will chain-load <command>nss-dns</command> if
+    <filename>systemd-resolved.service</filename> is not running, ensuring that basic DNS resolution continues to work
+    if the service is down.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Example</title>
+
+    <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables <command>nss-resolve</command>
+    correctly:</para>
+
+<programlisting>passwd:         compat mymachines systemd
+group:          compat mymachines systemd
+shadow:         compat
+
+hosts:          files mymachines <command>resolve [!UNAVAIL=return]</command> dns myhostname
+networks:       files
+
+protocols:      db files
+services:       db files
+ethers:         db files
+rpc:            db files
+
+netgroup:       nis</programlisting>
+
+    <para>This keeps the <command>dns</command> module as a fallback for cases where the <command>nss-resolve</command>
+    module is not installed.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>