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6e513a78ea
qemu/slirp/slirp.c
Marc-André Lureau 6e513a78ea slirp: remove slirp_instances list 
Now that polling is done per-instance, we don't need a global list of
slirp instances.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00

1143 lines
33 KiB
C
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/*
* libslirp glue
*
* Copyright (c) 2004-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "slirp.h"
#ifdef WITH_QEMU
#include "state.h"
#endif
#ifndef _WIN32
#include <net/if.h>
#endif
int slirp_debug;
/* Define to 1 if you want KEEPALIVE timers */
bool slirp_do_keepalive;
/* host loopback address */
struct in_addr loopback_addr;
/* host loopback network mask */
unsigned long loopback_mask;
/* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
static const uint8_t special_ethaddr[ETH_ALEN] = {
0x52, 0x55, 0x00, 0x00, 0x00, 0x00
};
unsigned curtime;
static struct in_addr dns_addr;
#ifndef _WIN32
static struct in6_addr dns6_addr;
#endif
static unsigned dns_addr_time;
#ifndef _WIN32
static unsigned dns6_addr_time;
#endif
#define TIMEOUT_FAST 2 /* milliseconds */
#define TIMEOUT_SLOW 499 /* milliseconds */
/* for the aging of certain requests like DNS */
#define TIMEOUT_DEFAULT 1000 /* milliseconds */
#ifdef _WIN32
int get_dns_addr(struct in_addr *pdns_addr)
{
FIXED_INFO *FixedInfo=NULL;
ULONG BufLen;
DWORD ret;
IP_ADDR_STRING *pIPAddr;
struct in_addr tmp_addr;
if (dns_addr.s_addr != 0 && (curtime - dns_addr_time) < TIMEOUT_DEFAULT) {
*pdns_addr = dns_addr;
return 0;
}
FixedInfo = (FIXED_INFO *)GlobalAlloc(GPTR, sizeof(FIXED_INFO));
BufLen = sizeof(FIXED_INFO);
if (ERROR_BUFFER_OVERFLOW == GetNetworkParams(FixedInfo, &BufLen)) {
if (FixedInfo) {
GlobalFree(FixedInfo);
FixedInfo = NULL;
}
FixedInfo = GlobalAlloc(GPTR, BufLen);
}
if ((ret = GetNetworkParams(FixedInfo, &BufLen)) != ERROR_SUCCESS) {
printf("GetNetworkParams failed. ret = %08x\n", (unsigned)ret );
if (FixedInfo) {
GlobalFree(FixedInfo);
FixedInfo = NULL;
}
return -1;
}
pIPAddr = &(FixedInfo->DnsServerList);
inet_aton(pIPAddr->IpAddress.String, &tmp_addr);
*pdns_addr = tmp_addr;
dns_addr = tmp_addr;
dns_addr_time = curtime;
if (FixedInfo) {
GlobalFree(FixedInfo);
FixedInfo = NULL;
}
return 0;
}
int get_dns6_addr(struct in6_addr *pdns6_addr, uint32_t *scope_id)
{
return -1;
}
static void winsock_cleanup(void)
{
WSACleanup();
}
#else
static int get_dns_addr_cached(void *pdns_addr, void *cached_addr,
socklen_t addrlen,
struct stat *cached_stat, unsigned *cached_time)
{
struct stat old_stat;
if (curtime - *cached_time < TIMEOUT_DEFAULT) {
memcpy(pdns_addr, cached_addr, addrlen);
return 0;
}
old_stat = *cached_stat;
if (stat("/etc/resolv.conf", cached_stat) != 0) {
return -1;
}
if (cached_stat->st_dev == old_stat.st_dev
&& cached_stat->st_ino == old_stat.st_ino
&& cached_stat->st_size == old_stat.st_size
&& cached_stat->st_mtime == old_stat.st_mtime) {
memcpy(pdns_addr, cached_addr, addrlen);
return 0;
}
return 1;
}
static int get_dns_addr_resolv_conf(int af, void *pdns_addr, void *cached_addr,
socklen_t addrlen, uint32_t *scope_id,
unsigned *cached_time)
{
char buff[512];
char buff2[257];
FILE *f;
int found = 0;
void *tmp_addr = alloca(addrlen);
unsigned if_index;
f = fopen("/etc/resolv.conf", "r");
if (!f)
return -1;
DEBUG_MISC("IP address of your DNS(s):");
while (fgets(buff, 512, f) != NULL) {
if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) {
char *c = strchr(buff2, '%');
if (c) {
if_index = if_nametoindex(c + 1);
*c = '\0';
} else {
if_index = 0;
}
if (!inet_pton(af, buff2, tmp_addr)) {
continue;
}
/* If it's the first one, set it to dns_addr */
if (!found) {
memcpy(pdns_addr, tmp_addr, addrlen);
memcpy(cached_addr, tmp_addr, addrlen);
if (scope_id) {
*scope_id = if_index;
}
*cached_time = curtime;
}
if (++found > 3) {
DEBUG_MISC(" (more)");
break;
} else if (slirp_debug & DBG_MISC) {
char s[INET6_ADDRSTRLEN];
const char *res = inet_ntop(af, tmp_addr, s, sizeof(s));
if (!res) {
res = " (string conversion error)";
}
DEBUG_MISC(" %s", res);
}
}
}
fclose(f);
if (!found)
return -1;
return 0;
}
int get_dns_addr(struct in_addr *pdns_addr)
{
static struct stat dns_addr_stat;
if (dns_addr.s_addr != 0) {
int ret;
ret = get_dns_addr_cached(pdns_addr, &dns_addr, sizeof(dns_addr),
&dns_addr_stat, &dns_addr_time);
if (ret <= 0) {
return ret;
}
}
return get_dns_addr_resolv_conf(AF_INET, pdns_addr, &dns_addr,
sizeof(dns_addr), NULL, &dns_addr_time);
}
int get_dns6_addr(struct in6_addr *pdns6_addr, uint32_t *scope_id)
{
static struct stat dns6_addr_stat;
if (!in6_zero(&dns6_addr)) {
int ret;
ret = get_dns_addr_cached(pdns6_addr, &dns6_addr, sizeof(dns6_addr),
&dns6_addr_stat, &dns6_addr_time);
if (ret <= 0) {
return ret;
}
}
return get_dns_addr_resolv_conf(AF_INET6, pdns6_addr, &dns6_addr,
sizeof(dns6_addr),
scope_id, &dns6_addr_time);
}
#endif
static void slirp_init_once(void)
{
static int initialized;
const char *debug;
#ifdef _WIN32
WSADATA Data;
#endif
if (initialized) {
return;
}
initialized = 1;
#ifdef _WIN32
WSAStartup(MAKEWORD(2,0), &Data);
atexit(winsock_cleanup);
#endif
loopback_addr.s_addr = htonl(INADDR_LOOPBACK);
loopback_mask = htonl(IN_CLASSA_NET);
debug = g_getenv("SLIRP_DEBUG");
if (debug) {
const GDebugKey keys[] = {
{ "call", DBG_CALL },
{ "misc", DBG_MISC },
{ "error", DBG_ERROR },
{ "tftp", DBG_TFTP },
};
slirp_debug = g_parse_debug_string(debug, keys, G_N_ELEMENTS(keys));
}
}
Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
struct in_addr vnetmask, struct in_addr vhost,
bool in6_enabled,
struct in6_addr vprefix_addr6, uint8_t vprefix_len,
struct in6_addr vhost6, const char *vhostname,
const char *tftp_server_name,
const char *tftp_path, const char *bootfile,
struct in_addr vdhcp_start, struct in_addr vnameserver,
struct in6_addr vnameserver6, const char **vdnssearch,
const char *vdomainname,
const SlirpCb *callbacks,
void *opaque)
{
Slirp *slirp = g_malloc0(sizeof(Slirp));
slirp_init_once();
slirp->cb = callbacks;
slirp->grand = g_rand_new();
slirp->restricted = restricted;
slirp->in_enabled = in_enabled;
slirp->in6_enabled = in6_enabled;
if_init(slirp);
ip_init(slirp);
ip6_init(slirp);
/* Initialise mbufs *after* setting the MTU */
m_init(slirp);
slirp->vnetwork_addr = vnetwork;
slirp->vnetwork_mask = vnetmask;
slirp->vhost_addr = vhost;
slirp->vprefix_addr6 = vprefix_addr6;
slirp->vprefix_len = vprefix_len;
slirp->vhost_addr6 = vhost6;
if (vhostname) {
slirp_pstrcpy(slirp->client_hostname, sizeof(slirp->client_hostname),
vhostname);
}
slirp->tftp_prefix = g_strdup(tftp_path);
slirp->bootp_filename = g_strdup(bootfile);
slirp->vdomainname = g_strdup(vdomainname);
slirp->vdhcp_startaddr = vdhcp_start;
slirp->vnameserver_addr = vnameserver;
slirp->vnameserver_addr6 = vnameserver6;
slirp->tftp_server_name = g_strdup(tftp_server_name);
if (vdnssearch) {
translate_dnssearch(slirp, vdnssearch);
}
slirp->opaque = opaque;
#ifdef WITH_QEMU
slirp_state_register(slirp);
#endif
return slirp;
}
void slirp_cleanup(Slirp *slirp)
{
struct gfwd_list *e, *next;
for (e = slirp->guestfwd_list; e; e = next) {
next = e->ex_next;
g_free(e->ex_exec);
g_free(e);
}
#ifdef WITH_QEMU
slirp_state_unregister(slirp);
#endif
ip_cleanup(slirp);
ip6_cleanup(slirp);
m_cleanup(slirp);
g_rand_free(slirp->grand);
g_free(slirp->vdnssearch);
g_free(slirp->tftp_prefix);
g_free(slirp->bootp_filename);
g_free(slirp->vdomainname);
g_free(slirp);
}
#define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
#define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
static void slirp_update_timeout(Slirp *slirp, uint32_t *timeout)
{
uint32_t t;
if (*timeout <= TIMEOUT_FAST) {
return;
}
t = MIN(1000, *timeout);
/* If we have tcp timeout with slirp, then we will fill @timeout with
* more precise value.
*/
if (slirp->time_fasttimo) {
*timeout = TIMEOUT_FAST;
return;
}
if (slirp->do_slowtimo) {
t = MIN(TIMEOUT_SLOW, t);
}
*timeout = t;
}
void slirp_pollfds_fill(Slirp *slirp, GArray *pollfds, uint32_t *timeout)
{
struct socket *so, *so_next;
/*
* First, TCP sockets
*/
/*
* *_slowtimo needs calling if there are IP fragments
* in the fragment queue, or there are TCP connections active
*/
slirp->do_slowtimo = ((slirp->tcb.so_next != &slirp->tcb) ||
(&slirp->ipq.ip_link != slirp->ipq.ip_link.next));
for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so_next) {
int events = 0;
so_next = so->so_next;
so->pollfds_idx = -1;
/*
* See if we need a tcp_fasttimo
*/
if (slirp->time_fasttimo == 0 &&
so->so_tcpcb->t_flags & TF_DELACK) {
slirp->time_fasttimo = curtime; /* Flag when want a fasttimo */
}
/*
* NOFDREF can include still connecting to local-host,
* newly socreated() sockets etc. Don't want to select these.
*/
if (so->so_state & SS_NOFDREF || so->s == -1) {
continue;
}
/*
* Set for reading sockets which are accepting
*/
if (so->so_state & SS_FACCEPTCONN) {
GPollFD pfd = {
.fd = so->s,
.events = G_IO_IN | G_IO_HUP | G_IO_ERR,
};
so->pollfds_idx = pollfds->len;
g_array_append_val(pollfds, pfd);
continue;
}
/*
* Set for writing sockets which are connecting
*/
if (so->so_state & SS_ISFCONNECTING) {
GPollFD pfd = {
.fd = so->s,
.events = G_IO_OUT | G_IO_ERR,
};
so->pollfds_idx = pollfds->len;
g_array_append_val(pollfds, pfd);
continue;
}
/*
* Set for writing if we are connected, can send more, and
* we have something to send
*/
if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) {
events |= G_IO_OUT | G_IO_ERR;
}
/*
* Set for reading (and urgent data) if we are connected, can
* receive more, and we have room for it XXX /2 ?
*/
if (CONN_CANFRCV(so) &&
(so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) {
events |= G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_PRI;
}
if (events) {
GPollFD pfd = {
.fd = so->s,
.events = events,
};
so->pollfds_idx = pollfds->len;
g_array_append_val(pollfds, pfd);
}
}
/*
* UDP sockets
*/
for (so = slirp->udb.so_next; so != &slirp->udb; so = so_next) {
so_next = so->so_next;
so->pollfds_idx = -1;
/*
* See if it's timed out
*/
if (so->so_expire) {
if (so->so_expire <= curtime) {
udp_detach(so);
continue;
} else {
slirp->do_slowtimo = true; /* Let socket expire */
}
}
/*
* When UDP packets are received from over the
* link, they're sendto()'d straight away, so
* no need for setting for writing
* Limit the number of packets queued by this session
* to 4. Note that even though we try and limit this
* to 4 packets, the session could have more queued
* if the packets needed to be fragmented
* (XXX <= 4 ?)
*/
if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) {
GPollFD pfd = {
.fd = so->s,
.events = G_IO_IN | G_IO_HUP | G_IO_ERR,
};
so->pollfds_idx = pollfds->len;
g_array_append_val(pollfds, pfd);
}
}
/*
* ICMP sockets
*/
for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so_next) {
so_next = so->so_next;
so->pollfds_idx = -1;
/*
* See if it's timed out
*/
if (so->so_expire) {
if (so->so_expire <= curtime) {
icmp_detach(so);
continue;
} else {
slirp->do_slowtimo = true; /* Let socket expire */
}
}
if (so->so_state & SS_ISFCONNECTED) {
GPollFD pfd = {
.fd = so->s,
.events = G_IO_IN | G_IO_HUP | G_IO_ERR,
};
so->pollfds_idx = pollfds->len;
g_array_append_val(pollfds, pfd);
}
}
slirp_update_timeout(slirp, timeout);
}
void slirp_pollfds_poll(Slirp *slirp, GArray *pollfds, int select_error)
{
struct socket *so, *so_next;
int ret;
curtime = slirp->cb->clock_get_ns() / SCALE_MS;
/*
* See if anything has timed out
*/
if (slirp->time_fasttimo &&
((curtime - slirp->time_fasttimo) >= TIMEOUT_FAST)) {
tcp_fasttimo(slirp);
slirp->time_fasttimo = 0;
}
if (slirp->do_slowtimo &&
((curtime - slirp->last_slowtimo) >= TIMEOUT_SLOW)) {
ip_slowtimo(slirp);
tcp_slowtimo(slirp);
slirp->last_slowtimo = curtime;
}
/*
* Check sockets
*/
if (!select_error) {
/*
* Check TCP sockets
*/
for (so = slirp->tcb.so_next; so != &slirp->tcb;
so = so_next) {
int revents;
so_next = so->so_next;
revents = 0;
if (so->pollfds_idx != -1) {
revents = g_array_index(pollfds, GPollFD,
so->pollfds_idx).revents;
}
if (so->so_state & SS_NOFDREF || so->s == -1) {
continue;
}
/*
* Check for URG data
* This will soread as well, so no need to
* test for G_IO_IN below if this succeeds
*/
if (revents & G_IO_PRI) {
ret = sorecvoob(so);
if (ret < 0) {
/* Socket error might have resulted in the socket being
* removed, do not try to do anything more with it. */
continue;
}
}
/*
* Check sockets for reading
*/
else if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) {
/*
* Check for incoming connections
*/
if (so->so_state & SS_FACCEPTCONN) {
tcp_connect(so);
continue;
} /* else */
ret = soread(so);
/* Output it if we read something */
if (ret > 0) {
tcp_output(sototcpcb(so));
}
if (ret < 0) {
/* Socket error might have resulted in the socket being
* removed, do not try to do anything more with it. */
continue;
}
}
/*
* Check sockets for writing
*/
if (!(so->so_state & SS_NOFDREF) &&
(revents & (G_IO_OUT | G_IO_ERR))) {
/*
* Check for non-blocking, still-connecting sockets
*/
if (so->so_state & SS_ISFCONNECTING) {
/* Connected */
so->so_state &= ~SS_ISFCONNECTING;
ret = send(so->s, (const void *) &ret, 0, 0);
if (ret < 0) {
/* XXXXX Must fix, zero bytes is a NOP */
if (errno == EAGAIN || errno == EWOULDBLOCK ||
errno == EINPROGRESS || errno == ENOTCONN) {
continue;
}
/* else failed */
so->so_state &= SS_PERSISTENT_MASK;
so->so_state |= SS_NOFDREF;
}
/* else so->so_state &= ~SS_ISFCONNECTING; */
/*
* Continue tcp_input
*/
tcp_input((struct mbuf *)NULL, sizeof(struct ip), so,
so->so_ffamily);
/* continue; */
} else {
ret = sowrite(so);
if (ret > 0) {
/* Call tcp_output in case we need to send a window
* update to the guest, otherwise it will be stuck
* until it sends a window probe. */
tcp_output(sototcpcb(so));
}
}
}
}
/*
* Now UDP sockets.
* Incoming packets are sent straight away, they're not buffered.
* Incoming UDP data isn't buffered either.
*/
for (so = slirp->udb.so_next; so != &slirp->udb;
so = so_next) {
int revents;
so_next = so->so_next;
revents = 0;
if (so->pollfds_idx != -1) {
revents = g_array_index(pollfds, GPollFD,
so->pollfds_idx).revents;
}
if (so->s != -1 &&
(revents & (G_IO_IN | G_IO_HUP | G_IO_ERR))) {
sorecvfrom(so);
}
}
/*
* Check incoming ICMP relies.
*/
for (so = slirp->icmp.so_next; so != &slirp->icmp;
so = so_next) {
int revents;
so_next = so->so_next;
revents = 0;
if (so->pollfds_idx != -1) {
revents = g_array_index(pollfds, GPollFD,
so->pollfds_idx).revents;
}
if (so->s != -1 &&
(revents & (G_IO_IN | G_IO_HUP | G_IO_ERR))) {
icmp_receive(so);
}
}
}
if_start(slirp);
}
static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
{
struct slirp_arphdr *ah = (struct slirp_arphdr *)(pkt + ETH_HLEN);
uint8_t arp_reply[MAX(ETH_HLEN + sizeof(struct slirp_arphdr), 64)];
struct ethhdr *reh = (struct ethhdr *)arp_reply;
struct slirp_arphdr *rah = (struct slirp_arphdr *)(arp_reply + ETH_HLEN);
int ar_op;
struct gfwd_list *ex_ptr;
if (!slirp->in_enabled) {
return;
}
ar_op = ntohs(ah->ar_op);
switch(ar_op) {
case ARPOP_REQUEST:
if (ah->ar_tip == ah->ar_sip) {
/* Gratuitous ARP */
arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
return;
}
if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) ==
slirp->vnetwork_addr.s_addr) {
if (ah->ar_tip == slirp->vnameserver_addr.s_addr ||
ah->ar_tip == slirp->vhost_addr.s_addr)
goto arp_ok;
for (ex_ptr = slirp->guestfwd_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
if (ex_ptr->ex_addr.s_addr == ah->ar_tip)
goto arp_ok;
}
return;
arp_ok:
memset(arp_reply, 0, sizeof(arp_reply));
arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
/* ARP request for alias/dns mac address */
memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
memcpy(&reh->h_source[2], &ah->ar_tip, 4);
reh->h_proto = htons(ETH_P_ARP);
rah->ar_hrd = htons(1);
rah->ar_pro = htons(ETH_P_IP);
rah->ar_hln = ETH_ALEN;
rah->ar_pln = 4;
rah->ar_op = htons(ARPOP_REPLY);
memcpy(rah->ar_sha, reh->h_source, ETH_ALEN);
rah->ar_sip = ah->ar_tip;
memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN);
rah->ar_tip = ah->ar_sip;
slirp_send_packet_all(slirp, arp_reply, sizeof(arp_reply));
}
break;
case ARPOP_REPLY:
arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
break;
default:
break;
}
}
void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
{
struct mbuf *m;
int proto;
if (pkt_len < ETH_HLEN)
return;
proto = (((uint16_t) pkt[12]) << 8) + pkt[13];
switch(proto) {
case ETH_P_ARP:
arp_input(slirp, pkt, pkt_len);
break;
case ETH_P_IP:
case ETH_P_IPV6:
m = m_get(slirp);
if (!m)
return;
/* Note: we add 2 to align the IP header on 4 bytes,
* and add the margin for the tcpiphdr overhead */
if (M_FREEROOM(m) < pkt_len + TCPIPHDR_DELTA + 2) {
m_inc(m, pkt_len + TCPIPHDR_DELTA + 2);
}
m->m_len = pkt_len + TCPIPHDR_DELTA + 2;
memcpy(m->m_data + TCPIPHDR_DELTA + 2, pkt, pkt_len);
m->m_data += TCPIPHDR_DELTA + 2 + ETH_HLEN;
m->m_len -= TCPIPHDR_DELTA + 2 + ETH_HLEN;
if (proto == ETH_P_IP) {
ip_input(m);
} else if (proto == ETH_P_IPV6) {
ip6_input(m);
}
break;
case ETH_P_NCSI:
ncsi_input(slirp, pkt, pkt_len);
break;
default:
break;
}
}
/* Prepare the IPv4 packet to be sent to the ethernet device. Returns 1 if no
* packet should be sent, 0 if the packet must be re-queued, 2 if the packet
* is ready to go.
*/
static int if_encap4(Slirp *slirp, struct mbuf *ifm, struct ethhdr *eh,
uint8_t ethaddr[ETH_ALEN])
{
const struct ip *iph = (const struct ip *)ifm->m_data;
if (iph->ip_dst.s_addr == 0) {
/* 0.0.0.0 can not be a destination address, something went wrong,
* avoid making it worse */
return 1;
}
if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
uint8_t arp_req[ETH_HLEN + sizeof(struct slirp_arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_req;
struct slirp_arphdr *rah = (struct slirp_arphdr *)(arp_req + ETH_HLEN);
if (!ifm->resolution_requested) {
/* If the client addr is not known, send an ARP request */
memset(reh->h_dest, 0xff, ETH_ALEN);
memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
memcpy(&reh->h_source[2], &slirp->vhost_addr, 4);
reh->h_proto = htons(ETH_P_ARP);
rah->ar_hrd = htons(1);
rah->ar_pro = htons(ETH_P_IP);
rah->ar_hln = ETH_ALEN;
rah->ar_pln = 4;
rah->ar_op = htons(ARPOP_REQUEST);
/* source hw addr */
memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4);
memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4);
/* source IP */
rah->ar_sip = slirp->vhost_addr.s_addr;
/* target hw addr (none) */
memset(rah->ar_tha, 0, ETH_ALEN);
/* target IP */
rah->ar_tip = iph->ip_dst.s_addr;
slirp->client_ipaddr = iph->ip_dst;
slirp_send_packet_all(slirp, arp_req, sizeof(arp_req));
ifm->resolution_requested = true;
/* Expire request and drop outgoing packet after 1 second */
ifm->expiration_date = slirp->cb->clock_get_ns() + 1000000000ULL;
}
return 0;
} else {
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
/* XXX: not correct */
memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
eh->h_proto = htons(ETH_P_IP);
/* Send this */
return 2;
}
}
/* Prepare the IPv6 packet to be sent to the ethernet device. Returns 1 if no
* packet should be sent, 0 if the packet must be re-queued, 2 if the packet
* is ready to go.
*/
static int if_encap6(Slirp *slirp, struct mbuf *ifm, struct ethhdr *eh,
uint8_t ethaddr[ETH_ALEN])
{
const struct ip6 *ip6h = mtod(ifm, const struct ip6 *);
if (!ndp_table_search(slirp, ip6h->ip_dst, ethaddr)) {
if (!ifm->resolution_requested) {
ndp_send_ns(slirp, ip6h->ip_dst);
ifm->resolution_requested = true;
ifm->expiration_date = slirp->cb->clock_get_ns() + 1000000000ULL;
}
return 0;
} else {
eh->h_proto = htons(ETH_P_IPV6);
in6_compute_ethaddr(ip6h->ip_src, eh->h_source);
/* Send this */
return 2;
}
}
/* Output the IP packet to the ethernet device. Returns 0 if the packet must be
* re-queued.
*/
int if_encap(Slirp *slirp, struct mbuf *ifm)
{
uint8_t buf[1600];
struct ethhdr *eh = (struct ethhdr *)buf;
uint8_t ethaddr[ETH_ALEN];
const struct ip *iph = (const struct ip *)ifm->m_data;
int ret;
if (ifm->m_len + ETH_HLEN > sizeof(buf)) {
return 1;
}
switch (iph->ip_v) {
case IPVERSION:
ret = if_encap4(slirp, ifm, eh, ethaddr);
if (ret < 2) {
return ret;
}
break;
case IP6VERSION:
ret = if_encap6(slirp, ifm, eh, ethaddr);
if (ret < 2) {
return ret;
}
break;
default:
g_assert_not_reached();
break;
}
memcpy(eh->h_dest, ethaddr, ETH_ALEN);
DEBUG_ARG("src = %02x:%02x:%02x:%02x:%02x:%02x",
eh->h_source[0], eh->h_source[1], eh->h_source[2],
eh->h_source[3], eh->h_source[4], eh->h_source[5]);
DEBUG_ARG("dst = %02x:%02x:%02x:%02x:%02x:%02x",
eh->h_dest[0], eh->h_dest[1], eh->h_dest[2],
eh->h_dest[3], eh->h_dest[4], eh->h_dest[5]);
memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
slirp_send_packet_all(slirp, buf, ifm->m_len + ETH_HLEN);
return 1;
}
/* Drop host forwarding rule, return 0 if found. */
int slirp_remove_hostfwd(Slirp *slirp, int is_udp, struct in_addr host_addr,
int host_port)
{
struct socket *so;
struct socket *head = (is_udp ? &slirp->udb : &slirp->tcb);
struct sockaddr_in addr;
int port = htons(host_port);
socklen_t addr_len;
for (so = head->so_next; so != head; so = so->so_next) {
addr_len = sizeof(addr);
if ((so->so_state & SS_HOSTFWD) &&
getsockname(so->s, (struct sockaddr *)&addr, &addr_len) == 0 &&
addr.sin_addr.s_addr == host_addr.s_addr &&
addr.sin_port == port) {
so->slirp->cb->unregister_poll_fd(so->s);
slirp_closesocket(so->s);
sofree(so);
return 0;
}
}
return -1;
}
int slirp_add_hostfwd(Slirp *slirp, int is_udp, struct in_addr host_addr,
int host_port, struct in_addr guest_addr, int guest_port)
{
if (!guest_addr.s_addr) {
guest_addr = slirp->vdhcp_startaddr;
}
if (is_udp) {
if (!udp_listen(slirp, host_addr.s_addr, htons(host_port),
guest_addr.s_addr, htons(guest_port), SS_HOSTFWD))
return -1;
} else {
if (!tcp_listen(slirp, host_addr.s_addr, htons(host_port),
guest_addr.s_addr, htons(guest_port), SS_HOSTFWD))
return -1;
}
return 0;
}
static bool
check_guestfwd(Slirp *slirp, struct in_addr *guest_addr, int guest_port)
{
struct gfwd_list *tmp_ptr;
if (!guest_addr->s_addr) {
guest_addr->s_addr = slirp->vnetwork_addr.s_addr |
(htonl(0x0204) & ~slirp->vnetwork_mask.s_addr);
}
if ((guest_addr->s_addr & slirp->vnetwork_mask.s_addr) !=
slirp->vnetwork_addr.s_addr ||
guest_addr->s_addr == slirp->vhost_addr.s_addr ||
guest_addr->s_addr == slirp->vnameserver_addr.s_addr) {
return false;
}
/* check if the port is "bound" */
for (tmp_ptr = slirp->guestfwd_list; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
if (guest_port == tmp_ptr->ex_fport &&
guest_addr->s_addr == tmp_ptr->ex_addr.s_addr)
return false;
}
return true;
}
int slirp_add_exec(Slirp *slirp, const char *cmdline,
struct in_addr *guest_addr, int guest_port)
{
if (!check_guestfwd(slirp, guest_addr, guest_port)) {
return -1;
}
add_exec(&slirp->guestfwd_list, cmdline, *guest_addr, htons(guest_port));
return 0;
}
int slirp_add_guestfwd(Slirp *slirp, SlirpWriteCb write_cb, void *opaque,
struct in_addr *guest_addr, int guest_port)
{
if (!check_guestfwd(slirp, guest_addr, guest_port)) {
return -1;
}
add_guestfwd(&slirp->guestfwd_list, write_cb, opaque,
*guest_addr, htons(guest_port));
return 0;
}
ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags)
{
if (so->s == -1 && so->guestfwd) {
/* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks */
so->guestfwd->write_cb(buf, len, so->guestfwd->opaque);
return len;
}
if (so->s == -1) {
/*
* This should in theory not happen but it is hard to be
* sure because some code paths will end up with so->s == -1
* on a failure but don't dispose of the struct socket.
* Check specifically, so we don't pass -1 to send().
*/
errno = EBADF;
return -1;
}
return send(so->s, buf, len, flags);
}
struct socket *
slirp_find_ctl_socket(Slirp *slirp, struct in_addr guest_addr, int guest_port)
{
struct socket *so;
for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
if (so->so_faddr.s_addr == guest_addr.s_addr &&
htons(so->so_fport) == guest_port) {
return so;
}
}
return NULL;
}
size_t slirp_socket_can_recv(Slirp *slirp, struct in_addr guest_addr,
int guest_port)
{
struct iovec iov[2];
struct socket *so;
so = slirp_find_ctl_socket(slirp, guest_addr, guest_port);
if (!so || so->so_state & SS_NOFDREF) {
return 0;
}
if (!CONN_CANFRCV(so) || so->so_snd.sb_cc >= (so->so_snd.sb_datalen/2)) {
return 0;
}
return sopreprbuf(so, iov, NULL);
}
void slirp_socket_recv(Slirp *slirp, struct in_addr guest_addr, int guest_port,
const uint8_t *buf, int size)
{
int ret;
struct socket *so = slirp_find_ctl_socket(slirp, guest_addr, guest_port);
if (!so)
return;
ret = soreadbuf(so, (const char *)buf, size);
if (ret > 0)
tcp_output(sototcpcb(so));
}
void slirp_send_packet_all(Slirp *slirp, const void *buf, size_t len)
{
ssize_t ret = slirp->cb->send_packet(buf, len, slirp->opaque);
if (ret < 0) {
g_critical("Failed to send packet, ret: %ld", (long) ret);
} else if (ret < len) {
DEBUG_ERROR("send_packet() didn't send all data: %ld < %lu",
(long) ret, (unsigned long) len);
}
}
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