nss-myhostname: move to subdirectory

In order to merge into the systemd repos.

1 files changed, 451 insertions, 0 deletions

diff --git a/src/nss-myhostname/nss-myhostname.c b/src/nss-myhostname/nss-myhostname.c
new file mode 100644
index 0000000000..83180ad805
--- /dev/null
+++ b/src/nss-myhostname/nss-myhostname.c
@@ -0,0 +1,451 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of nss-myhostname.
+
+  Copyright 2008-2011 Lennart Poettering
+
+  nss-myhostname 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.
+
+  nss-myhostname 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 nss-myhostname; If not, see
+  <http://www.gnu.org/licenses/>.
+***/
+
+#include <limits.h>
+#include <nss.h>
+#include <sys/types.h>
+#include <netdb.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <unistd.h>
+#include <net/if.h>
+#include <stdlib.h>
+#include <arpa/inet.h>
+
+#include "ifconf.h"
+
+/* We use 127.0.0.2 as IPv4 address. This has the advantage over
+ * 127.0.0.1 that it can be translated back to the local hostname. For
+ * IPv6 we use ::1 which unfortunately will not translate back to the
+ * hostname but instead something like "localhost6" or so. */
+
+#define LOCALADDRESS_IPV4 (htonl(0x7F000002))
+#define LOCALADDRESS_IPV6 &in6addr_loopback
+#define LOOPBACK_INTERFACE "lo"
+
+#define ALIGN(a) (((a+sizeof(void*)-1)/sizeof(void*))*sizeof(void*))
+
+enum nss_status _nss_myhostname_gethostbyname4_r(
+                const char *name,
+                struct gaih_addrtuple **pat,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp) _public_;
+
+enum nss_status _nss_myhostname_gethostbyname3_r(
+                const char *name,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp,
+                char **canonp) _public_;
+
+enum nss_status _nss_myhostname_gethostbyname2_r(
+                const char *name,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop) _public_;
+
+enum nss_status _nss_myhostname_gethostbyname_r(
+                const char *name,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop) _public_;
+
+enum nss_status _nss_myhostname_gethostbyaddr2_r(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp) _public_;
+
+enum nss_status _nss_myhostname_gethostbyaddr_r(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop) _public_;
+
+enum nss_status _nss_myhostname_gethostbyname4_r(
+                const char *name,
+                struct gaih_addrtuple **pat,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp) {
+
+        unsigned lo_ifi;
+        char hn[HOST_NAME_MAX+1];
+        size_t l, idx, ms;
+        char *r_name;
+        struct gaih_addrtuple *r_tuple, *r_tuple_prev = NULL;
+        struct address *addresses = NULL, *a;
+        unsigned n_addresses = 0, n;
+
+        memset(hn, 0, sizeof(hn));
+        if (gethostname(hn, sizeof(hn)-1) < 0) {
+                *errnop = errno;
+                *h_errnop = NO_RECOVERY;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (strcasecmp(name, hn) != 0) {
+                *errnop = ENOENT;
+                *h_errnop = HOST_NOT_FOUND;
+                return NSS_STATUS_NOTFOUND;
+        }
+
+        /* If this fails, n_addresses is 0. Which is fine */
+        ifconf_acquire_addresses(&addresses, &n_addresses);
+
+        /* If this call fails we fill in 0 as scope. Which is fine */
+        lo_ifi = if_nametoindex(LOOPBACK_INTERFACE);
+
+        l = strlen(hn);
+        ms = ALIGN(l+1)+ALIGN(sizeof(struct gaih_addrtuple))*(n_addresses > 0 ? n_addresses : 2);
+        if (buflen < ms) {
+                *errnop = ENOMEM;
+                *h_errnop = NO_RECOVERY;
+                free(addresses);
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        /* First, fill in hostname */
+        r_name = buffer;
+        memcpy(r_name, hn, l+1);
+        idx = ALIGN(l+1);
+
+        if (n_addresses <= 0) {
+                /* Second, fill in IPv6 tuple */
+                r_tuple = (struct gaih_addrtuple*) (buffer + idx);
+                r_tuple->next = r_tuple_prev;
+                r_tuple->name = r_name;
+                r_tuple->family = AF_INET6;
+                memcpy(r_tuple->addr, LOCALADDRESS_IPV6, 16);
+                r_tuple->scopeid = (uint32_t) lo_ifi;
+
+                idx += ALIGN(sizeof(struct gaih_addrtuple));
+                r_tuple_prev = r_tuple;
+
+                /* Third, fill in IPv4 tuple */
+                r_tuple = (struct gaih_addrtuple*) (buffer + idx);
+                r_tuple->next = r_tuple_prev;
+                r_tuple->name = r_name;
+                r_tuple->family = AF_INET;
+                *(uint32_t*) r_tuple->addr = LOCALADDRESS_IPV4;
+                r_tuple->scopeid = (uint32_t) lo_ifi;
+
+                idx += ALIGN(sizeof(struct gaih_addrtuple));
+                r_tuple_prev = r_tuple;
+        }
+
+        /* Fourth, fill actual addresses in, but in backwards order */
+        for (a = addresses + n_addresses - 1, n = 0; n < n_addresses; n++, a--) {
+                r_tuple = (struct gaih_addrtuple*) (buffer + idx);
+                r_tuple->next = r_tuple_prev;
+                r_tuple->name = r_name;
+                r_tuple->family = a->family;
+                r_tuple->scopeid = a->ifindex;
+                memcpy(r_tuple->addr, a->address, 16);
+
+                idx += ALIGN(sizeof(struct gaih_addrtuple));
+                r_tuple_prev = r_tuple;
+        }
+
+        /* Verify the size matches */
+        assert(idx == ms);
+
+        *pat = r_tuple_prev;
+
+        if (ttlp)
+                *ttlp = 0;
+
+        free(addresses);
+
+        return NSS_STATUS_SUCCESS;
+}
+
+static enum nss_status fill_in_hostent(
+                const char *hn,
+                int af,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp,
+                char **canonp) {
+
+        size_t l, idx, ms;
+        char *r_addr, *r_name, *r_aliases, *r_addr_list;
+        size_t alen;
+        struct address *addresses = NULL, *a;
+        unsigned n_addresses = 0, n, c;
+
+        alen = PROTO_ADDRESS_SIZE(af);
+
+        ifconf_acquire_addresses(&addresses, &n_addresses);
+
+        for (a = addresses, n = 0, c = 0; n < n_addresses; a++, n++)
+                if (af == a->family)
+                        c++;
+
+        l = strlen(hn);
+        ms = ALIGN(l+1)+
+                sizeof(char*)+
+                (c > 0 ? c : 1)*ALIGN(alen)+
+                (c > 0 ? c+1 : 2)*sizeof(char*);
+
+        if (buflen < ms) {
+                *errnop = ENOMEM;
+                *h_errnop = NO_RECOVERY;
+                free(addresses);
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        /* First, fill in hostname */
+        r_name = buffer;
+        memcpy(r_name, hn, l+1);
+        idx = ALIGN(l+1);
+
+        /* Second, create (empty) aliases array */
+        r_aliases = buffer + idx;
+        *(char**) r_aliases = NULL;
+        idx += sizeof(char*);
+
+        /* Third, add addresses */
+        r_addr = buffer + idx;
+        if (c > 0) {
+                unsigned i = 0;
+
+                for (a = addresses, n = 0; n < n_addresses; a++, n++) {
+                        if (af != a->family)
+                                continue;
+
+                        memcpy(r_addr + i*ALIGN(alen), a->address, alen);
+                        i++;
+                }
+
+                assert(i == c);
+                idx += c*ALIGN(alen);
+        } else {
+                if (af == AF_INET)
+                        *(uint32_t*) r_addr = LOCALADDRESS_IPV4;
+                else
+                        memcpy(r_addr, LOCALADDRESS_IPV6, 16);
+
+                idx += ALIGN(alen);
+        }
+
+        /* Fourth, add address pointer array */
+        r_addr_list = buffer + idx;
+        if (c > 0) {
+                unsigned i = 0;
+
+                for (a = addresses, n = 0; n < n_addresses; a++, n++) {
+                        if (af != a->family)
+                                continue;
+
+                        ((char**) r_addr_list)[i] = (r_addr + i*ALIGN(alen));
+                        i++;
+                }
+
+                assert(i == c);
+                ((char**) r_addr_list)[c] = NULL;
+                idx += (c+1)*sizeof(char*);
+
+        } else {
+                ((char**) r_addr_list)[0] = r_addr;
+                ((char**) r_addr_list)[1] = NULL;
+                idx += 2*sizeof(char*);
+        }
+
+        /* Verify the size matches */
+        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;
+
+        if (ttlp)
+                *ttlp = 0;
+
+        if (canonp)
+                *canonp = r_name;
+
+        free(addresses);
+
+        return NSS_STATUS_SUCCESS;
+}
+
+enum nss_status _nss_myhostname_gethostbyname3_r(
+                const char *name,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp,
+                char **canonp) {
+
+        char hn[HOST_NAME_MAX+1];
+
+        if (af == AF_UNSPEC)
+                af = AF_INET;
+
+        if (af != AF_INET && af != AF_INET6) {
+                *errnop = EAFNOSUPPORT;
+                *h_errnop = NO_DATA;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        memset(hn, 0, sizeof(hn));
+        if (gethostname(hn, sizeof(hn)-1) < 0) {
+                *errnop = errno;
+                *h_errnop = NO_RECOVERY;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (strcasecmp(name, hn) != 0) {
+                *errnop = ENOENT;
+                *h_errnop = HOST_NOT_FOUND;
+                return NSS_STATUS_NOTFOUND;
+        }
+
+        return fill_in_hostent(hn, af, host, buffer, buflen, errnop, h_errnop, ttlp, canonp);
+}
+
+enum nss_status _nss_myhostname_gethostbyname2_r(
+                const char *name,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop) {
+
+        return _nss_myhostname_gethostbyname3_r(
+                        name,
+                        af,
+                        host,
+                        buffer, buflen,
+                        errnop, h_errnop,
+                        NULL,
+                        NULL);
+}
+
+enum nss_status _nss_myhostname_gethostbyname_r(
+                const char *name,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop) {
+
+        return _nss_myhostname_gethostbyname3_r(
+                        name,
+                        AF_UNSPEC,
+                        host,
+                        buffer, buflen,
+                        errnop, h_errnop,
+                        NULL,
+                        NULL);
+}
+
+enum nss_status _nss_myhostname_gethostbyaddr2_r(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp) {
+
+        char hn[HOST_NAME_MAX+1];
+        struct address *addresses = NULL, *a;
+        unsigned n_addresses = 0, n;
+
+        if (len != PROTO_ADDRESS_SIZE(af)) {
+                *errnop = EINVAL;
+                *h_errnop = NO_RECOVERY;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (af == AF_INET) {
+
+                if ((*(uint32_t*) addr) == LOCALADDRESS_IPV4)
+                        goto found;
+
+        } else if (af == AF_INET6) {
+
+                if (memcmp(addr, LOCALADDRESS_IPV6, 16) == 0)
+                        goto found;
+
+        } else {
+                *errnop = EAFNOSUPPORT;
+                *h_errnop = NO_DATA;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        ifconf_acquire_addresses(&addresses, &n_addresses);
+
+        for (a = addresses, n = 0; n < n_addresses; n++, a++) {
+                if (af != a->family)
+                        continue;
+
+                if (memcmp(addr, a->address, PROTO_ADDRESS_SIZE(af)) == 0)
+                        goto found;
+        }
+
+        *errnop = ENOENT;
+        *h_errnop = HOST_NOT_FOUND;
+
+        free(addresses);
+        return NSS_STATUS_NOTFOUND;
+
+found:
+        free(addresses);
+
+        memset(hn, 0, sizeof(hn));
+        if (gethostname(hn, sizeof(hn)-1) < 0) {
+                *errnop = errno;
+                *h_errnop = NO_RECOVERY;
+
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        return fill_in_hostent(hn, af, host, buffer, buflen, errnop, h_errnop, ttlp, NULL);
+
+}
+
+enum nss_status _nss_myhostname_gethostbyaddr_r(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop) {
+
+        return _nss_myhostname_gethostbyaddr2_r(
+                        addr, len,
+                        af,
+                        host,
+                        buffer, buflen,
+                        errnop, h_errnop,
+                        NULL);
+}