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qemu/slirp/slirp.c
Marc-André Lureau fdbfba8cbf slirp: remove slirp_ prefix for socket wrappers 
QEMU wraps the socket functions in os-win32.h, but in commit
a9d8b3ec43, the header inclusion was dropped,
breaking libslirp on Windows.

There are already a few socket functions that are wrapped in libslirp,
with "slirp_" prefix, but many of them are missing, and we are going
to wrap the missing functions in a second patch.

Using "slirp_" prefix avoids the conflict with socket function #define
wrappers in QEMU os-win32.h, but they are quite intrusive. In the end,
the functions should behave the same as original one, but with errno
being set. To avoid the churn, and potential confusion, remove the
"slirp_" prefix. A series of #undef is necessary until libslirp is
made standalone to prevent the #define conflict with QEMU.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190212160953.29051-2-marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-12 20:47:42 +01:00

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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->opaque = opaque;
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);
}
#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, uint32_t *timeout,
SlirpAddPollCb add_poll, void *opaque)
{
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) {
so->pollfds_idx = add_poll(so->s,
SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_ERR, opaque);
continue;
}
/*
* Set for writing sockets which are connecting
*/
if (so->so_state & SS_ISFCONNECTING) {
so->pollfds_idx = add_poll(so->s,
SLIRP_POLL_OUT | SLIRP_POLL_ERR, opaque);
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 |= SLIRP_POLL_OUT | SLIRP_POLL_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 |= SLIRP_POLL_IN | SLIRP_POLL_HUP |
SLIRP_POLL_ERR | SLIRP_POLL_PRI;
}
if (events) {
so->pollfds_idx = add_poll(so->s, events, opaque);
}
}
/*
* 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) {
so->pollfds_idx = add_poll(so->s,
SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_ERR, opaque);
}
}
/*
* 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) {
so->pollfds_idx = add_poll(so->s,
SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_ERR, opaque);
}
}
slirp_update_timeout(slirp, timeout);
}
void slirp_pollfds_poll(Slirp *slirp, int select_error,
SlirpGetREventsCb get_revents, void *opaque)
{
struct socket *so, *so_next;
int ret;
curtime = slirp->cb->clock_get_ns(slirp->opaque) / 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 = get_revents(so->pollfds_idx, opaque);
}
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 SLIRP_POLL_IN below if this succeeds
*/
if (revents & SLIRP_POLL_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 &
(SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_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 & (SLIRP_POLL_OUT | SLIRP_POLL_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 = get_revents(so->pollfds_idx, opaque);
}
if (so->s != -1 &&
(revents & (SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_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 = get_revents(so->pollfds_idx, opaque);
}
if (so->s != -1 &&
(revents & (SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_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(slirp->opaque) + 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(slirp->opaque) + 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, so->slirp->opaque);
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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