diff options
Diffstat (limited to 'usr.sbin/ntpd/client.c')
| -rw-r--r-- | usr.sbin/ntpd/client.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/usr.sbin/ntpd/client.c b/usr.sbin/ntpd/client.c new file mode 100644 index 00000000000..c742d1d11fb --- /dev/null +++ b/usr.sbin/ntpd/client.c @@ -0,0 +1,129 @@ +/* $OpenBSD: client.c,v 1.1 2004/06/17 19:17:48 henning Exp $ */ + +/* + * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> + * Copyright (c) 2004 Alexander Guy <alexander.guy@andern.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER + * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING + * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/param.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +#include "ntpd.h" + +int +client_peer_init(struct ntp_peer *p) +{ + struct sockaddr_in *sa_in; + struct sockaddr_in6 *sa_in6; + + if ((p->query = calloc(1, sizeof(struct ntp_msg))) == NULL) + fatal("client_query calloc"); + + switch (p->ss.ss_family) { + case AF_INET: + sa_in = (struct sockaddr_in *)&p->ss; + if (ntohs(sa_in->sin_port) == 0) + sa_in->sin_port = htons(123); + break; + case AF_INET6: + sa_in6 = (struct sockaddr_in6 *)&p->ss; + if (ntohs(sa_in6->sin6_port) == 0) + sa_in6->sin6_port = htons(123); + break; + default: + fatal("king bula sez: wrong AF in client_peer_init"); + /* not reached */ + } + + if ((p->query->fd = socket(p->ss.ss_family, SOCK_DGRAM, 0)) == -1) + fatal("client_query socket"); + + p->query->msg.status = MODE_CLIENT | (NTP_VERSION << 3); + p->state = STATE_NONE; + p->next = time(NULL); + + return (0); +} + +int +client_query(struct ntp_peer *p) +{ + /* + * Send out a random 64-bit number as our transmit time. The NTP + * server will copy said number into the originate field on the + * response that it sends us. This is totally legal per the SNTP spec. + * + * The impact of this is two fold: we no longer send out the current + * system time for the world to see (which may aid an attacker), and + * it gives us a (not very secure) way of knowing that we're not + * getting spoofed by an attacker that can't capture our traffic + * but can spoof packets from the NTP server we're communicating with. + * + * Save the real transmit timestamp locally. + */ + + p->query->msg.xmttime.int_part = arc4random(); + p->query->msg.xmttime.fraction = arc4random(); + get_ts(&p->query->xmttime); + + ntp_sendmsg(p->query->fd, (struct sockaddr *)&p->ss, &p->query->msg, + NTP_MSGSIZE_NOAUTH, 0); + p->state = STATE_QUERY_SENT; + p->next = 0; + p->deadline = time(NULL) + MAX_QUERYTIME; + + return (0); +} + +int +client_dispatch(struct ntp_peer *p) +{ + struct sockaddr_storage fsa; + socklen_t fsa_len; + char buf[NTP_MSGSIZE]; + ssize_t size; + struct ntp_msg msg; + struct l_fixedpt rtt, t; + + fsa_len = sizeof(fsa); + if ((size = recvfrom(p->query->fd, &buf, sizeof(buf), 0, + (struct sockaddr *)&fsa, &fsa_len)) == -1) + fatal("recvfrom"); + + ntp_getmsg(buf, size, &msg); + + if (msg.orgtime.int_part != p->query->msg.xmttime.int_part || + msg.orgtime.fraction != p->query->msg.xmttime.fraction) { + log_warn("received packet without correct cookie, discarding"); + return (0); + } + +log_debug("reply received"); + + /* XXX parse */ + get_ts(&t); + rtt.int_part = (t.int_part - p->query->xmttime.int_part) - + (msg.rectime.int_part - msg.xmttime.int_part); + + p->state = STATE_REPLY_RECEIVED; + p->next = time(NULL) + QUERY_INTERVAL; + p->deadline = 0; + + return (0); +} |