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sys/netinet/netdump/netdump_client.c

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/*-
* Copyright (c) 2005-2014 Sandvine Incorporated. All rights reserved.
* Copyright (c) 2000 Darrell Anderson <anderson@cs.duke.edu>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* netdump_client.c
* FreeBSD subsystem supporting netdump network dumps.
* A dedicated server must be running to accept client dumps.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/disk.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/kerneldump.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_options.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/netdump/netdump.h>
#include <machine/in_cksum.h>
#include <machine/pcb.h>
#define NETDDEBUG(f, ...) do { \
if (nd_debug > 0) \
printf(("%s: " f), __func__, ## __VA_ARGS__); \
} while (0)
#define NETDDEBUG_IF(i, f, ...) do { \
if (nd_debug > 0) \
if_printf((i), ("%s: " f), __func__, ## __VA_ARGS__); \
} while (0)
#define NETDDEBUGV(f, ...) do { \
if (nd_debug > 1) \
printf(("%s: " f), __func__, ## __VA_ARGS__); \
} while (0)
#define NETDDEBUGV_IF(i, f, ...) do { \
if (nd_debug > 1) \
if_printf((i), ("%s: " f), __func__, ## __VA_ARGS__); \
} while (0)
static int netdump_arp_gw(void);
static void netdump_cleanup(void);
static int netdump_configure(struct netdump_conf *);
static int netdump_dumper(void *priv __unused, void *virtual,
vm_offset_t physical __unused, off_t offset, size_t length);
static int netdump_ether_output(struct mbuf *m, struct ifnet *ifp,
struct ether_addr dst, u_short etype);
static void netdump_handle_arp(struct mbuf **mb);
static void netdump_handle_ip(struct mbuf **mb);
static int netdump_ioctl(struct cdev *dev __unused, u_long cmd,
caddr_t addr, int flags __unused, struct thread *td);
static int netdump_modevent(module_t mod, int type, void *priv);
static void netdump_network_poll(void);
static void netdump_pkt_in(struct ifnet *ifp, struct mbuf *m);
static int netdump_send(uint32_t type, off_t offset, unsigned char *data,
uint32_t datalen);
static int netdump_send_arp(in_addr_t dst);
static int netdump_start(struct dumperinfo *di);
static int netdump_udp_output(struct mbuf *m);
/* Must be at least as big as the chunks dumpsys() gives us. */
static unsigned char nd_buf[MAXDUMPPGS * PAGE_SIZE];
static uint32_t nd_seqno;
static int dump_failed, have_gw_mac;
static void (*drv_if_input)(struct ifnet *, struct mbuf *);
static int restore_gw_addr;
static uint64_t rcvd_acks;
CTASSERT(sizeof(rcvd_acks) * NBBY == NETDUMP_MAX_IN_FLIGHT);
/*
* Times to poll the NIC (0.5ms each poll) before assuming packetloss
* occurred (default to 1s).
*/
static int nd_polls = 2000;
/* Times to retransmit lost packets. */
static int nd_retries = 10;
/* Number of ARP retries. */
static int nd_arp_retries = 3;
/* Configuration parameters. */
static struct netdump_conf nd_conf;
#define nd_server nd_conf.ndc_server
#define nd_client nd_conf.ndc_client
#define nd_gateway nd_conf.ndc_gateway
/* General dynamic settings. */
static struct ether_addr nd_gw_mac;
static struct ifnet *nd_ifp;
static uint16_t nd_server_port = NETDUMP_PORT;
FEATURE(netdump, "Netdump client support");
static SYSCTL_NODE(_net, OID_AUTO, netdump, CTLFLAG_RD, NULL,
"netdump parameters");
static int nd_debug;
SYSCTL_INT(_net_netdump, OID_AUTO, debug, CTLFLAG_RWTUN,
&nd_debug, 0,
"Debug message verbosity");
static int nd_enabled;
SYSCTL_INT(_net_netdump, OID_AUTO, enabled, CTLFLAG_RD,
&nd_enabled, 0,
"netdump configuration status");
static char nd_path[MAXPATHLEN];
SYSCTL_STRING(_net_netdump, OID_AUTO, path, CTLFLAG_RW,
nd_path, sizeof(nd_path),
"Server path for output files");
/*
* Checks for netdump support on a network interface
*
* Parameters:
* ifp The network interface that is being tested for support
*
* Returns:
* int 1 if the interface is supported, 0 if not
*/
static bool
netdump_supported_nic(struct ifnet *ifp)
{
return (ifp->if_netdump_methods != NULL);
}
/*-
* Network specific primitives.
* Following down the code they are divided ordered as:
* - Packet buffer primitives
* - Output primitives
* - Input primitives
* - Polling primitives
*/
/*
* Handles creation of the ethernet header, then places outgoing packets into
* the tx buffer for the NIC
*
* Parameters:
* m The mbuf containing the packet to be sent (will be freed by
* this function or the NIC driver)
* ifp The interface to send on
* dst The destination ethernet address (source address will be looked
* up using ifp)
* etype The ETHERTYPE_* value for the protocol that is being sent
*
* Returns:
* int see errno.h, 0 for success
*/
static int
netdump_ether_output(struct mbuf *m, struct ifnet *ifp, struct ether_addr dst,
u_short etype)
{
struct ether_header *eh;
if (((ifp->if_flags & (IFF_MONITOR | IFF_UP)) != IFF_UP) ||
(ifp->if_drv_flags & IFF_DRV_RUNNING) != IFF_DRV_RUNNING) {
if_printf(ifp, "netdump_ether_output: interface isn't up\n");
m_freem(m);
return (ENETDOWN);
}
/* Fill in the ethernet header. */
M_PREPEND(m, ETHER_HDR_LEN, M_NOWAIT);
if (m == NULL) {
printf("%s: out of mbufs\n", __func__);
return (ENOBUFS);
}
eh = mtod(m, struct ether_header *);
memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
memcpy(eh->ether_dhost, dst.octet, ETHER_ADDR_LEN);
eh->ether_type = htons(etype);
return ((ifp->if_netdump_methods->nd_transmit)(ifp, m));
}
/*
* Unreliable transmission of an mbuf chain to the netdump server
* Note: can't handle fragmentation; fails if the packet is larger than
* nd_ifp->if_mtu after adding the UDP/IP headers
*
* Parameters:
* m mbuf chain
*
* Returns:
* int see errno.h, 0 for success
*/
static int
netdump_udp_output(struct mbuf *m)
{
struct udpiphdr *ui;
struct ip *ip;
MPASS(nd_ifp != NULL);
M_PREPEND(m, sizeof(struct udpiphdr), M_NOWAIT);
if (m == NULL) {
printf("%s: out of mbufs\n", __func__);
return (ENOBUFS);
}
if (m->m_pkthdr.len > nd_ifp->if_mtu) {
printf("netdump_udp_output: Packet is too big: %d > MTU %u\n",
m->m_pkthdr.len, nd_ifp->if_mtu);
m_freem(m);
return (ENOBUFS);
}
ui = mtod(m, struct udpiphdr *);
bzero(ui->ui_x1, sizeof(ui->ui_x1));
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = htons(m->m_pkthdr.len - sizeof(struct ip));
ui->ui_ulen = ui->ui_len;
ui->ui_src = nd_client;
ui->ui_dst = nd_server;
/* Use this src port so that the server can connect() the socket */
ui->ui_sport = htons(NETDUMP_ACKPORT);
ui->ui_dport = htons(nd_server_port);
ui->ui_sum = 0;
if ((ui->ui_sum = in_cksum(m, m->m_pkthdr.len)) == 0)
ui->ui_sum = 0xffff;
ip = mtod(m, struct ip *);
ip->ip_v = IPVERSION;
ip->ip_hl = sizeof(struct ip) >> 2;
ip->ip_tos = 0;
ip->ip_len = htons(m->m_pkthdr.len);
ip->ip_id = 0;
ip->ip_off = htons(IP_DF);
ip->ip_ttl = 255;
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m, sizeof(struct ip));
return (netdump_ether_output(m, nd_ifp, nd_gw_mac, ETHERTYPE_IP));
}
/*
* Builds and sends a single ARP request to locate the server
*
* Return value:
* 0 on success
* errno on error
*/
static int
netdump_send_arp(in_addr_t dst)
{
struct ether_addr bcast;
struct mbuf *m;
struct arphdr *ah;
int pktlen;
MPASS(nd_ifp != NULL);
/* Fill-up a broadcast address. */
memset(&bcast, 0xFF, ETHER_ADDR_LEN);
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
printf("netdump_send_arp: Out of mbufs\n");
return (ENOBUFS);
}
pktlen = arphdr_len2(ETHER_ADDR_LEN, sizeof(struct in_addr));
m->m_len = pktlen;
m->m_pkthdr.len = pktlen;
MH_ALIGN(m, pktlen);
ah = mtod(m, struct arphdr *);
ah->ar_hrd = htons(ARPHRD_ETHER);
ah->ar_pro = htons(ETHERTYPE_IP);
ah->ar_hln = ETHER_ADDR_LEN;
ah->ar_pln = sizeof(struct in_addr);
ah->ar_op = htons(ARPOP_REQUEST);
memcpy(ar_sha(ah), IF_LLADDR(nd_ifp), ETHER_ADDR_LEN);
((struct in_addr *)ar_spa(ah))->s_addr = nd_client.s_addr;
bzero(ar_tha(ah), ETHER_ADDR_LEN);
((struct in_addr *)ar_tpa(ah))->s_addr = dst;
return (netdump_ether_output(m, nd_ifp, bcast, ETHERTYPE_ARP));
}
/*
* Sends ARP requests to locate the server and waits for a response.
* We first try to ARP the server itself, and fall back to the provided
* gateway if the server appears to be off-link.
*
* Return value:
* 0 on success
* errno on error
*/
static int
netdump_arp_gw(void)
{
in_addr_t dst;
int error, polls, retries;
dst = nd_server.s_addr;
restart:
for (retries = 0; retries < nd_arp_retries && have_gw_mac == 0;
retries++) {
error = netdump_send_arp(dst);
if (error != 0)
return (error);
for (polls = 0; polls < nd_polls && have_gw_mac == 0; polls++) {
netdump_network_poll();
DELAY(500);
}
if (have_gw_mac == 0)
printf("(ARP retry)");
}
if (have_gw_mac != 0)
return (0);
if (dst == nd_server.s_addr && nd_server.s_addr != nd_gateway.s_addr) {
printf("Failed to ARP server, trying to reach gateway...\n");
dst = nd_gateway.s_addr;
goto restart;
}
printf("\nARP timed out.\n");
return (ETIMEDOUT);
}
/*
* Dummy free function for netdump clusters.
*/
static void
netdump_mbuf_free(struct mbuf *m __unused)
{
}
/*
* Construct and reliably send a netdump packet. May fail from a resource
* shortage or extreme number of unacknowledged retransmissions. Wait for
* an acknowledgement before returning. Splits packets into chunks small
* enough to be sent without fragmentation (looks up the interface MTU)
*
* Parameters:
* type netdump packet type (HERALD, FINISHED, or VMCORE)
* offset vmcore data offset (bytes)
* data vmcore data
* datalen vmcore data size (bytes)
*
* Returns:
* int see errno.h, 0 for success
*/
static int
netdump_send(uint32_t type, off_t offset, unsigned char *data, uint32_t datalen)
{
struct netdump_msg_hdr *nd_msg_hdr;
struct mbuf *m, *m2;
uint64_t want_acks;
uint32_t i, pktlen, sent_so_far;
int retries, polls, error;
want_acks = 0;
rcvd_acks = 0;
retries = 0;
MPASS(nd_ifp != NULL);
retransmit:
/* Chunks can be too big to fit in packets. */
for (i = sent_so_far = 0; sent_so_far < datalen ||
(i == 0 && datalen == 0); i++) {
pktlen = datalen - sent_so_far;
/* First bound: the packet structure. */
pktlen = min(pktlen, NETDUMP_DATASIZE);
/* Second bound: the interface MTU (assume no IP options). */
pktlen = min(pktlen, nd_ifp->if_mtu - sizeof(struct udpiphdr) -
sizeof(struct netdump_msg_hdr));
/*
* Check if it is retransmitting and this has been ACKed
* already.
*/
if ((rcvd_acks & (1 << i)) != 0) {
sent_so_far += pktlen;
continue;
}
/*
* Get and fill a header mbuf, then chain data as an extended
* mbuf.
*/
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
printf("netdump_send: Out of mbufs\n");
return (ENOBUFS);
}
m->m_len = sizeof(struct netdump_msg_hdr);
m->m_pkthdr.len = sizeof(struct netdump_msg_hdr);
MH_ALIGN(m, sizeof(struct netdump_msg_hdr));
nd_msg_hdr = mtod(m, struct netdump_msg_hdr *);
nd_msg_hdr->mh_seqno = htonl(nd_seqno + i);
nd_msg_hdr->mh_type = htonl(type);
nd_msg_hdr->mh_offset = htobe64(offset + sent_so_far);
nd_msg_hdr->mh_len = htonl(pktlen);
nd_msg_hdr->mh__pad = 0;
if (pktlen != 0) {
m2 = m_get(M_NOWAIT, MT_DATA);
if (m2 == NULL) {
m_freem(m);
printf("netdump_send: Out of mbufs\n");
return (ENOBUFS);
}
MEXTADD(m2, data + sent_so_far, pktlen,
netdump_mbuf_free, NULL, NULL, 0, EXT_DISPOSABLE);
m2->m_len = pktlen;
m_cat(m, m2);
m->m_pkthdr.len += pktlen;
}
error = netdump_udp_output(m);
if (error != 0)
return (error);
/* Note that we're waiting for this packet in the bitfield. */
want_acks |= (1 << i);
sent_so_far += pktlen;
}
if (i >= NETDUMP_MAX_IN_FLIGHT)
printf("Warning: Sent more than %d packets (%d). "
"Acknowledgements will fail unless the size of "
"rcvd_acks/want_acks is increased.\n",
NETDUMP_MAX_IN_FLIGHT, i);
/*
* Wait for acks. A *real* window would speed things up considerably.
*/
polls = 0;
while (rcvd_acks != want_acks) {
if (polls++ > nd_polls) {
if (retries++ > nd_retries)
return (ETIMEDOUT);
printf(". ");
goto retransmit;
}
netdump_network_poll();
DELAY(500);
}
nd_seqno += i;
return (0);
}
/*
* Handler for IP packets: checks their sanity and then processes any netdump
* ACK packets it finds.
*
* It needs to replicate partially the behaviour of ip_input() and
* udp_input().
*
* Parameters:
* mb a pointer to an mbuf * containing the packet received
* Updates *mb if m_pullup et al change the pointer
* Assumes the calling function will take care of freeing the mbuf
*/
static void
netdump_handle_ip(struct mbuf **mb)
{
struct ip *ip;
struct udpiphdr *udp;
struct netdump_ack *nd_ack;
struct mbuf *m;
int rcv_ackno;
unsigned short hlen;
/* IP processing. */
m = *mb;
if (m->m_pkthdr.len < sizeof(struct ip)) {
NETDDEBUG("dropping packet too small for IP header\n");
return;
}
if (m->m_len < sizeof(struct ip)) {
m = m_pullup(m, sizeof(struct ip));
*mb = m;
if (m == NULL) {
NETDDEBUG("m_pullup failed\n");
return;
}
}
ip = mtod(m, struct ip *);
/* IP version. */
if (ip->ip_v != IPVERSION) {
NETDDEBUG("bad IP version %d\n", ip->ip_v);
return;
}
/* Header length. */
hlen = ip->ip_hl << 2;
if (hlen < sizeof(struct ip)) {
NETDDEBUG("bad IP header length (%hu)\n", hlen);
return;
}
if (hlen > m->m_len) {
m = m_pullup(m, hlen);
*mb = m;
if (m == NULL) {
NETDDEBUG("m_pullup failed\n");
return;
}
ip = mtod(m, struct ip *);
}
/* Ignore packets with IP options. */
if (hlen > sizeof(struct ip)) {
NETDDEBUG("drop packet with IP options\n");
return;
}
#ifdef INVARIANTS
if (((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
(ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) &&
(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
NETDDEBUG("Bad IP header (RFC1122)\n");
return;
}
#endif
/* Checksum. */
if ((m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) != 0) {
if ((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0) {
NETDDEBUG("bad IP checksum\n");
return;
}
} else {
/* XXX */ ;
}
/* Convert fields to host byte order. */
ip->ip_len = ntohs(ip->ip_len);
if (ip->ip_len < hlen) {
NETDDEBUG("IP packet smaller (%hu) than header (%hu)\n",
ip->ip_len, hlen);
return;
}
if (m->m_pkthdr.len < ip->ip_len) {
NETDDEBUG("IP packet bigger (%hu) than ethernet packet (%d)\n",
ip->ip_len, m->m_pkthdr.len);
return;
}
if (m->m_pkthdr.len > ip->ip_len) {
/* Truncate the packet to the IP length. */
if (m->m_len == m->m_pkthdr.len) {
m->m_len = ip->ip_len;
m->m_pkthdr.len = ip->ip_len;
} else
m_adj(m, ip->ip_len - m->m_pkthdr.len);
}
ip->ip_off = ntohs(ip->ip_off);
/* Check that the source is the server's IP. */
if (ip->ip_src.s_addr != nd_server.s_addr) {
NETDDEBUG("drop packet not from server (from 0x%x)\n",
ip->ip_src.s_addr);
return;
}
/* Check if the destination IP is ours. */
if (ip->ip_dst.s_addr != nd_client.s_addr) {
NETDDEBUGV("drop packet not to our IP\n");
return;
}
if (ip->ip_p != IPPROTO_UDP) {
NETDDEBUG("drop non-UDP packet\n");
return;
}
/* Do not deal with fragments. */
if ((ip->ip_off & (IP_MF | IP_OFFMASK)) != 0) {
NETDDEBUG("drop fragmented packet\n");
return;
}
/* UDP custom is to have packet length not include IP header. */
ip->ip_len -= hlen;
/* UDP processing. */
/* Get IP and UDP headers together, along with the netdump packet. */
if (m->m_pkthdr.len <
sizeof(struct udpiphdr) + sizeof(struct netdump_ack)) {
NETDDEBUG("ignoring small packet\n");
return;
}
if (m->m_len < sizeof(struct udpiphdr) + sizeof(struct netdump_ack)) {
m = m_pullup(m, sizeof(struct udpiphdr) +
sizeof(struct netdump_ack));
*mb = m;
if (m == NULL) {
NETDDEBUG("m_pullup failed\n");
return;
}
}
udp = mtod(m, struct udpiphdr *);
if (ntohs(udp->ui_u.uh_dport) != NETDUMP_ACKPORT) {
NETDDEBUG("not on the netdump port.\n");
return;
}
/* Netdump processing. */
/*
* Packet is meant for us. Extract the ack sequence number and the
* port number if necessary.
*/
nd_ack = (struct netdump_ack *)(mtod(m, caddr_t) +
sizeof(struct udpiphdr));
rcv_ackno = ntohl(nd_ack->na_seqno);
if (nd_server_port == NETDUMP_PORT)
nd_server_port = ntohs(udp->ui_u.uh_sport);
if (rcv_ackno >= nd_seqno + NETDUMP_MAX_IN_FLIGHT)
printf("%s: ACK %d too far in future!\n", __func__, rcv_ackno);
else if (rcv_ackno >= nd_seqno) {
/* We're interested in this ack. Record it. */
rcvd_acks |= 1 << (rcv_ackno - nd_seqno);
}
}
/*
* Handler for ARP packets: checks their sanity and then
* 1. If the ARP is a request for our IP, respond with our MAC address
* 2. If the ARP is a response from our server, record its MAC address
*
* It needs to replicate partially the behaviour of arpintr() and
* in_arpinput().
*
* Parameters:
* mb a pointer to an mbuf * containing the packet received
* Updates *mb if m_pullup et al change the pointer
* Assumes the calling function will take care of freeing the mbuf
*/
static void
netdump_handle_arp(struct mbuf **mb)
{
char buf[INET_ADDRSTRLEN];
struct in_addr isaddr, itaddr, myaddr;
struct ether_addr dst;
struct mbuf *m;
struct arphdr *ah;
struct ifnet *ifp;
uint8_t *enaddr;
int req_len, op;
m = *mb;
ifp = m->m_pkthdr.rcvif;
if (m->m_len < sizeof(struct arphdr)) {
m = m_pullup(m, sizeof(struct arphdr));
*mb = m;
if (m == NULL) {
NETDDEBUG("runt packet: m_pullup failed\n");
return;
}
}
ah = mtod(m, struct arphdr *);
if (ntohs(ah->ar_hrd) != ARPHRD_ETHER) {
NETDDEBUG("unknown hardware address 0x%2D)\n",
(unsigned char *)&ah->ar_hrd, "");
return;
}
if (ntohs(ah->ar_pro) != ETHERTYPE_IP) {
NETDDEBUG("drop ARP for unknown protocol %d\n",
ntohs(ah->ar_pro));
return;
}
req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
if (m->m_len < req_len) {
m = m_pullup(m, req_len);
*mb = m;
if (m == NULL) {
NETDDEBUG("runt packet: m_pullup failed\n");
return;
}
}
ah = mtod(m, struct arphdr *);
op = ntohs(ah->ar_op);
memcpy(&isaddr, ar_spa(ah), sizeof(isaddr));
memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr));
enaddr = (uint8_t *)IF_LLADDR(ifp);
myaddr = nd_client;
if (memcmp(ar_sha(ah), enaddr, ifp->if_addrlen) == 0) {
NETDDEBUG("ignoring ARP from myself\n");
return;
}
if (isaddr.s_addr == nd_client.s_addr) {
printf("%s: %*D is using my IP address %s!\n", __func__,
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
inet_ntoa_r(isaddr, buf));
return;
}
if (memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen) == 0) {
NETDDEBUG("ignoring ARP from broadcast address\n");
return;
}
if (op == ARPOP_REPLY) {
if (isaddr.s_addr != nd_gateway.s_addr &&
isaddr.s_addr != nd_server.s_addr) {
inet_ntoa_r(isaddr, buf);
NETDDEBUG(
"ignoring ARP reply from %s (not netdump server)\n",
buf);
return;
}
memcpy(nd_gw_mac.octet, ar_sha(ah),
min(ah->ar_hln, ETHER_ADDR_LEN));
have_gw_mac = 1;
NETDDEBUG("got server MAC address %6D\n", nd_gw_mac.octet, ":");
return;
}
if (op != ARPOP_REQUEST) {
NETDDEBUG("ignoring ARP non-request/reply\n");
return;
}
if (itaddr.s_addr != nd_client.s_addr) {
NETDDEBUG("ignoring ARP not to our IP\n");
return;
}
memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
memcpy(ar_sha(ah), enaddr, ah->ar_hln);
memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
ah->ar_op = htons(ARPOP_REPLY);
ah->ar_pro = htons(ETHERTYPE_IP);
m->m_flags &= ~(M_BCAST|M_MCAST);
m->m_len = arphdr_len(ah);
m->m_pkthdr.len = m->m_len;
memcpy(dst.octet, ar_tha(ah), ETHER_ADDR_LEN);
netdump_ether_output(m, ifp, dst, ETHERTYPE_ARP);
*mb = NULL;
}
/*
* Handler for incoming packets directly from the network adapter
* Identifies the packet type (IP or ARP) and passes it along to one of the
* helper functions netdump_handle_ip or netdump_handle_arp.
*
* It needs to replicate partially the behaviour of ether_input() and
* ether_demux().
*
* Parameters:
* ifp the interface the packet came from (should be nd_ifp)
* m an mbuf containing the packet received
*/
static void
netdump_pkt_in(struct ifnet *ifp, struct mbuf *m)
{
struct ether_header *eh;
u_short etype;
/* Ethernet processing. */
if ((m->m_flags & M_PKTHDR) == 0) {
NETDDEBUG_IF(ifp, "discard frame without packet header\n");
goto done;
}
if (m->m_len < ETHER_HDR_LEN) {
NETDDEBUG_IF(ifp,
"discard frame without leading eth header (len %u pktlen %u)\n",
m->m_len, m->m_pkthdr.len);
goto done;
}
if ((m->m_flags & M_HASFCS) != 0) {
m_adj(m, -ETHER_CRC_LEN);
m->m_flags &= ~M_HASFCS;
}
eh = mtod(m, struct ether_header *);
etype = ntohs(eh->ether_type);
if ((m->m_flags & M_VLANTAG) != 0 || etype == ETHERTYPE_VLAN) {
NETDDEBUG_IF(ifp, "ignoring vlan packets\n");
goto done;
}
/* XXX: Probably must also check if we're the recipient MAC address. */
julianUnsubmitted
Not Done
Inline Actions

probably..

julian: probably..
/* Done ethernet processing. Strip off the ethernet header. */
m_adj(m, ETHER_HDR_LEN);
switch (etype) {
case ETHERTYPE_ARP:
netdump_handle_arp(&m);
break;
case ETHERTYPE_IP:
netdump_handle_ip(&m);
break;
default:
NETDDEBUG_IF(ifp, "dropping unknown ethertype %hu\n", etype);
break;
}
done:
if (m != NULL)
m_freem(m);
}
/*
* After trapping, instead of assuming that most of the network stack is sane,
* we just poll the driver directly for packets.
*/
static void
netdump_network_poll(void)
{
MPASS(nd_ifp != NULL);
nd_ifp->if_netdump_methods->nd_poll(nd_ifp, 1000);
}
/*-
* Dumping specific primitives.
*/
/*
* Callback from dumpsys() to dump a chunk of memory.
* Copies it out to our static buffer then sends it across the network.
* Detects the initial KDH and makes sure it is given a special packet type.
*
* Parameters:
* priv Unused. Optional private pointer.
* virtual Virtual address (where to read the data from)
* physical Unused. Physical memory address.
* offset Offset from start of core file
* length Data length
*
* Return value:
* 0 on success
* errno on error
*/
static int
netdump_dumper(void *priv __unused, void *virtual,
vm_offset_t physical __unused, off_t offset, size_t length)
{
int error;
NETDDEBUGV("netdump_dumper(NULL, %p, NULL, %ju, %zu)\n",
virtual, (uintmax_t)offset, length);
if (virtual == NULL) {
if (dump_failed != 0)
printf("failed to dump the kernel core\n");
else if (netdump_send(NETDUMP_FINISHED, 0, NULL, 0) != 0)
printf("failed to close the transaction\n");
else
printf("\nnetdump finished.\n");
netdump_cleanup();
return (0);
}
if (length > sizeof(nd_buf))
return (ENOSPC);
memmove(nd_buf, virtual, length);
error = netdump_send(NETDUMP_VMCORE, offset, nd_buf, length);
if (error != 0) {
dump_failed = 1;
return (error);
}
return (0);
}
/*
* Perform any initalization needed prior to transmitting the kernel core.
*/
static int
netdump_start(struct dumperinfo *di)
{
char *path;
char buf[INET_ADDRSTRLEN];
uint32_t len;
int error;
error = 0;
/* Check if the dumping is allowed to continue. */
if (nd_enabled == 0)
return (EINVAL);
MPASS(nd_ifp != NULL);
if (nd_server.s_addr == INADDR_ANY) {
printf("netdump_start: can't netdump; no server IP given\n");
return (EINVAL);
}
if (nd_client.s_addr == INADDR_ANY) {
printf("netdump_start: can't netdump; no client IP given\n");
return (EINVAL);
}
/* We start dumping at offset 0. */
di->dumpoff = 0;
nd_seqno = 1;
/*
* nd_server_port could have switched after the first ack the
* first time it gets called. Adjust it accordingly.
*/
nd_server_port = NETDUMP_PORT;
/* Switch to the netdump mbuf zones. */
netdump_mbuf_dump();
nd_ifp->if_netdump_methods->nd_event(nd_ifp, NETDUMP_START);
/* Make the card use *our* receive callback. */
drv_if_input = nd_ifp->if_input;
nd_ifp->if_input = netdump_pkt_in;
if (nd_gateway.s_addr == INADDR_ANY) {
restore_gw_addr = 1;
nd_gateway.s_addr = nd_server.s_addr;
}
printf("netdump in progress. searching for server...\n");
if (netdump_arp_gw()) {
printf("failed to locate server MAC address\n");
error = EINVAL;
goto trig_abort;
}
if (nd_path[0] != '\0') {
path = nd_path;
len = strlen(path) + 1;
} else {
path = NULL;
len = 0;
}
if (netdump_send(NETDUMP_HERALD, 0, path, len) != 0) {
printf("failed to contact netdump server\n");
error = EINVAL;
goto trig_abort;
}
printf("netdumping to %s (%6D)\n", inet_ntoa_r(nd_server, buf),
nd_gw_mac.octet, ":");
return (0);
trig_abort:
netdump_cleanup();
return (error);
}
static int
netdump_write_headers(struct dumperinfo *di, struct kerneldumpheader *kdh,
void *key, uint32_t keysize)
{
int error;
memcpy(nd_buf, kdh, sizeof(*kdh));
error = netdump_send(NETDUMP_KDH, 0, nd_buf, sizeof(*kdh));
if (error == 0 && keysize > 0) {
if (keysize > sizeof(nd_buf))
return (EINVAL);
memcpy(nd_buf, key, keysize);
error = netdump_send(NETDUMP_EKCD_KEY, 0, nd_buf, keysize);
}
return (error);
}
/*
* Cleanup routine for a possibly failed netdump.
*/
static void
netdump_cleanup(void)
{
if (restore_gw_addr != 0) {
nd_gateway.s_addr = INADDR_ANY;
restore_gw_addr = 0;
}
if (drv_if_input != NULL) {
nd_ifp->if_input = drv_if_input;
drv_if_input = NULL;
}
nd_ifp->if_netdump_methods->nd_event(nd_ifp, NETDUMP_END);
}
/*-
* KLD specific code.
*/
static struct cdevsw netdump_cdevsw = {
.d_version = D_VERSION,
.d_ioctl = netdump_ioctl,
.d_name = "netdump",
};
static struct cdev *netdump_cdev;
static int
netdump_configure(struct netdump_conf *conf)
{
struct ifnet *ifp;
IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if (strcmp(ifp->if_xname, conf->ndc_iface) == 0)
break;
}
/* XXX ref */
IFNET_RUNLOCK_NOSLEEP();
if (ifp == NULL)
return (ENOENT);
if ((if_getflags(ifp) & IFF_UP) == 0)
return (ENXIO);
if (!netdump_supported_nic(ifp) || ifp->if_type != IFT_ETHER)
return (EINVAL);
nd_ifp = ifp;
netdump_reinit(ifp);
memcpy(&nd_conf, conf, sizeof(nd_conf));
nd_enabled = 1;
return (0);
}
/*
* Reinitialize the mbuf pool used by drivers while dumping. This is called
* from the generic ioctl handler for SIOCSIFMTU after the driver has
* reconfigured itself.
*/
void
netdump_reinit(struct ifnet *ifp)
{
int clsize, nmbuf, ncl, nrxr;
if (ifp != nd_ifp)
return;
ifp->if_netdump_methods->nd_init(ifp, &nrxr, &ncl, &clsize);
KASSERT(nrxr > 0, ("invalid receive ring count %d", nrxr));
/*
* We need two headers per message on the transmit side. Multiply by
* four to give us some breathing room.
*/
nmbuf = ncl * (4 + nrxr);
ncl *= nrxr;
netdump_mbuf_reinit(nmbuf, ncl, clsize);
}
/*
* ioctl(2) handler for the netdump device. This is currently only used to
* register netdump as a dump device.
*
* Parameters:
* dev, Unused.
* cmd, The ioctl to be handled.
* addr, The parameter for the ioctl.
* flags, Unused.
* td, The thread invoking this ioctl.
*
* Returns:
* 0 on success, and an errno value on failure.
*/
static int
netdump_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
int flags __unused, struct thread *td)
{
struct diocskerneldump_arg *kda;
struct dumperinfo dumper;
struct netdump_conf *conf;
uint8_t *encryptedkey;
int error;
u_int u;
error = 0;
switch (cmd) {
case DIOCSKERNELDUMP:
u = *(u_int *)addr;
if (u != 0) {
error = ENXIO;
break;
}
if (nd_enabled) {
nd_enabled = 0;
netdump_mbuf_drain();
}
break;
case NETDUMPGCONF:
conf = (struct netdump_conf *)addr;
if (!nd_enabled) {
error = ENXIO;
break;
}
strlcpy(conf->ndc_iface, nd_ifp->if_xname,
sizeof(conf->ndc_iface));
memcpy(&conf->ndc_server, &nd_server, sizeof(nd_server));
memcpy(&conf->ndc_client, &nd_client, sizeof(nd_client));
memcpy(&conf->ndc_gateway, &nd_gateway, sizeof(nd_gateway));
break;
case NETDUMPSCONF:
conf = (struct netdump_conf *)addr;
encryptedkey = NULL;
kda = &conf->ndc_kda;
conf->ndc_iface[sizeof(conf->ndc_iface) - 1] = '\0';
if (kda->kda_enable == 0) {
if (nd_enabled) {
error = clear_dumper(td);
if (error == 0)
nd_enabled = 0;
}
break;
}
error = netdump_configure(conf);
if (error != 0)
break;
if (kda->kda_encryption != KERNELDUMP_ENC_NONE) {
if (kda->kda_encryptedkeysize <= 0 ||
kda->kda_encryptedkeysize >
KERNELDUMP_ENCKEY_MAX_SIZE)
return (EINVAL);
encryptedkey = malloc(kda->kda_encryptedkeysize, M_TEMP,
M_WAITOK);
error = copyin(kda->kda_encryptedkey, encryptedkey,
kda->kda_encryptedkeysize);
if (error != 0) {
free(encryptedkey, M_TEMP);
return (error);
}
}
dumper.dumper_start = netdump_start;
dumper.dumper_hdr = netdump_write_headers;
dumper.dumper = netdump_dumper;
dumper.priv = NULL;
dumper.blocksize = NETDUMP_DATASIZE;
dumper.maxiosize = MAXDUMPPGS * PAGE_SIZE;
dumper.mediaoffset = 0;
dumper.mediasize = 0;
error = set_dumper(&dumper, conf->ndc_iface, td,
kda->kda_compression, kda->kda_encryption,
kda->kda_key, kda->kda_encryptedkeysize,
encryptedkey);
if (encryptedkey != NULL) {
explicit_bzero(encryptedkey, kda->kda_encryptedkeysize);
free(encryptedkey, M_TEMP);
}
if (error != 0)
nd_enabled = 0;
break;
default:
error = EINVAL;
break;
}
return (error);
}
/*
* Called upon system init or kld load. Initializes the netdump parameters to
* sane defaults (locates the first available NIC and uses the first IPv4 IP on
* that card as the client IP). Leaves the server IP unconfigured.
*
* Parameters:
* mod, Unused.
* what, The module event type.
* priv, Unused.
*
* Returns:
* int, An errno value if an error occured, 0 otherwise.
*/
static int
netdump_modevent(module_t mod __unused, int what, void *priv __unused)
{
struct netdump_conf conf;
char *arg;
int error;
error = 0;
switch (what) {
case MOD_LOAD:
error = make_dev_p(MAKEDEV_WAITOK, &netdump_cdev,
&netdump_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "netdump");
if (error != 0)
return (error);
if ((arg = kern_getenv("net.dump.iface")) != NULL) {
strlcpy(conf.ndc_iface, arg, sizeof(conf.ndc_iface));
freeenv(arg);
if ((arg = kern_getenv("net.dump.server")) != NULL) {
inet_aton(arg, &conf.ndc_server);
freeenv(arg);
}
if ((arg = kern_getenv("net.dump.client")) != NULL) {
inet_aton(arg, &conf.ndc_server);
freeenv(arg);
}
if ((arg = kern_getenv("net.dump.gateway")) != NULL) {
inet_aton(arg, &conf.ndc_server);
freeenv(arg);
}
/* Ignore errors; we print a message to the console. */
(void)netdump_configure(&conf);
}
break;
case MOD_UNLOAD:
destroy_dev(netdump_cdev);
if (nd_enabled) {
printf("netdump: disabling dump device for unload\n");
(void)clear_dumper(curthread);
nd_enabled = 0;
}
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static moduledata_t netdump_mod = {
"netdump",
netdump_modevent,
NULL,
};
MODULE_VERSION(netdump, 1);
DECLARE_MODULE(netdump, netdump_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);