Merge nss-myhostname

1 files changed, 209 insertions, 0 deletions

diff --git a/src/nss-myhostname/netlink.c b/src/nss-myhostname/netlink.c
new file mode 100644
index 0000000000..29f38e3a00
--- /dev/null
+++ b/src/nss-myhostname/netlink.c
@@ -0,0 +1,209 @@
+/*-*- 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 <sys/socket.h>
+#include <sys/un.h>
+#include <asm/types.h>
+#include <inttypes.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <stdlib.h>
+
+#include "ifconf.h"
+
+int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list) {
+
+        struct {
+                struct nlmsghdr hdr;
+                struct rtgenmsg gen;
+        } req;
+        struct rtgenmsg *gen;
+        int fd, r, on = 1;
+        uint32_t seq = 4711;
+        struct address *list = NULL;
+        unsigned n_list = 0;
+
+        fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+        if (fd < 0)
+                return -errno;
+
+        if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) {
+                r = -errno;
+                goto finish;
+        }
+
+        memset(&req, 0, sizeof(req));
+        req.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
+        req.hdr.nlmsg_type = RTM_GETADDR;
+        req.hdr.nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP|NLM_F_ACK;
+        req.hdr.nlmsg_seq = seq;
+        req.hdr.nlmsg_pid = 0;
+
+        gen = NLMSG_DATA(&req.hdr);
+        gen->rtgen_family = AF_UNSPEC;
+
+        if (send(fd, &req, req.hdr.nlmsg_len, 0) < 0) {
+                r = -errno;
+                goto finish;
+        }
+
+        for (;;) {
+                ssize_t bytes;
+                struct msghdr msg;
+                struct cmsghdr *cmsg;
+                struct ucred *ucred;
+                struct iovec iov;
+                struct nlmsghdr *p;
+                uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred))];
+                struct {
+                        struct nlmsghdr hdr;
+                        struct ifaddrmsg ifaddrmsg;
+                        uint8_t payload[16*1024];
+                } resp;
+
+                memset(&iov, 0, sizeof(iov));
+                iov.iov_base = &resp;
+                iov.iov_len = sizeof(resp);
+
+                memset(&msg, 0, sizeof(msg));
+                msg.msg_name = NULL;
+                msg.msg_namelen = 0;
+                msg.msg_iov = &iov;
+                msg.msg_iovlen = 1;
+                msg.msg_control = cred_buffer;
+                msg.msg_controllen = sizeof(cred_buffer);
+                msg.msg_flags = 0;
+
+                bytes = recvmsg(fd, &msg, 0);
+                if (bytes < 0) {
+                        r = -errno;
+                        goto finish;
+                }
+
+                cmsg = CMSG_FIRSTHDR(&msg);
+                if (!cmsg || cmsg->cmsg_type != SCM_CREDENTIALS) {
+                        r = -EIO;
+                        goto finish;
+                }
+
+                ucred = (struct ucred*) CMSG_DATA(cmsg);
+                if (ucred->uid != 0 || ucred->pid != 0)
+                        continue;
+
+                for (p = &resp.hdr; bytes > 0; p = NLMSG_NEXT(p, bytes)) {
+                        struct ifaddrmsg *ifaddrmsg;
+                        struct rtattr *a;
+                        size_t l;
+                        void *local = NULL, *address = NULL;
+
+                        if (!NLMSG_OK(p, (size_t) bytes)) {
+                                r = -EIO;
+                                goto finish;
+                        }
+
+                        if (p->nlmsg_seq != seq)
+                                continue;
+
+                        if (p->nlmsg_type == NLMSG_DONE) {
+                                r = 0;
+                                goto finish;
+                        }
+
+                        if (p->nlmsg_type == NLMSG_ERROR) {
+                                struct nlmsgerr *nlmsgerr;
+
+                                nlmsgerr = NLMSG_DATA(p);
+                                r = -nlmsgerr->error;
+                                goto finish;
+                        }
+
+                        if (p->nlmsg_type != RTM_NEWADDR)
+                                continue;
+
+                        ifaddrmsg = NLMSG_DATA(p);
+
+                        if (ifaddrmsg->ifa_family != AF_INET &&
+                            ifaddrmsg->ifa_family != AF_INET6)
+                                continue;
+
+                        if (ifaddrmsg->ifa_scope == RT_SCOPE_HOST ||
+                            ifaddrmsg->ifa_scope == RT_SCOPE_NOWHERE)
+                                continue;
+
+                        if (ifaddrmsg->ifa_flags & IFA_F_DEPRECATED)
+                                continue;
+
+                        l = NLMSG_PAYLOAD(p, sizeof(struct ifaddrmsg));
+                        a = IFA_RTA(ifaddrmsg);
+
+                        while (RTA_OK(a, l)) {
+
+                                if (a->rta_type == IFA_ADDRESS)
+                                        address = RTA_DATA(a);
+                                else if (a->rta_type == IFA_LOCAL)
+                                        local = RTA_DATA(a);
+
+                                a = RTA_NEXT(a, l);
+                        }
+
+                        if (local)
+                                address = local;
+
+                        if (!address)
+                                continue;
+
+                        list = realloc(list, (n_list+1) * sizeof(struct address));
+                        if (!list) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                        list[n_list].family = ifaddrmsg->ifa_family;
+                        list[n_list].scope = ifaddrmsg->ifa_scope;
+                        memcpy(list[n_list].address, address, ifaddrmsg->ifa_family == AF_INET ? 4 : 16);
+                        list[n_list].ifindex = ifaddrmsg->ifa_index;
+
+                        n_list++;
+                }
+        }
+
+finish:
+        close(fd);
+
+        if (r < 0)
+                free(list);
+        else {
+                qsort(list, n_list, sizeof(struct address), address_compare);
+
+                *_list = list;
+                *_n_list = n_list;
+        }
+
+        return r;
+}