Google Git
Sign in
qemu / libslirp / 857d5ed77d9f0f0cc5122eb7200fa44f3af1053e / . / src / slirp.c
blob: 5e08b538030eabd1756f2787b19f99078760f661 [file] [log] [blame]
/* SPDX-License-Identifier: MIT */
/*
* 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"
#ifndef _WIN32
#include <net/if.h>
#endif
/* https://gitlab.freedesktop.org/slirp/libslirp/issues/18 */
#if defined(__NetBSD__) && defined(if_mtu)
#undef if_mtu
#endif
#if defined(_WIN32)
#define INITIAL_DNS_ADDR_BUF_SIZE 32 * 1024
#define REALLOC_RETRIES 5
// Broadcast site local DNS resolvers. We do not use these because they are
// highly unlikely to be valid.
// https://www.ietf.org/proceedings/52/I-D/draft-ietf-ipngwg-dns-discovery-03.txt
static const struct in6_addr SITE_LOCAL_DNS_BROADCAST_ADDRS[] = {
{
{{
0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01
}}
},
{
{{
0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02
}}
},
{
{{
0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
}}
},
};
#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;
static struct in6_addr dns6_addr;
static uint32_t dns6_scope_id;
static unsigned dns_addr_time;
static unsigned dns6_addr_time;
#define TIMEOUT_FAST 2 /* milliseconds */
#define TIMEOUT_SLOW 499 /* milliseconds */
/* for the aging of certain requests like DNS */
#define TIMEOUT_DEFAULT 1000 /* milliseconds */
#if defined(_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 is_site_local_dns_broadcast(struct in6_addr *address)
{
int i;
for (i = 0; i < G_N_ELEMENTS(SITE_LOCAL_DNS_BROADCAST_ADDRS); i++) {
if (in6_equal(address, &SITE_LOCAL_DNS_BROADCAST_ADDRS[i])) {
return 1;
}
}
return 0;
}
void print_dns_v6_address(struct in6_addr address)
{
char address_str[INET6_ADDRSTRLEN] = "";
if (inet_ntop(AF_INET6, &address, address_str, INET6_ADDRSTRLEN)
== NULL) {
DEBUG_ERROR("Failed to stringify IPv6 address for logging.");
return;
}
DEBUG_CALL("IPv6 DNS server found: %s", address_str);
}
// Gets the first valid DNS resolver with an IPv6 address.
// Ignores any site local broadcast DNS servers, as these
// are on deprecated addresses and not generally expected
// to work. Further details at:
// https://www.ietf.org/proceedings/52/I-D/draft-ietf-ipngwg-dns-discovery-03.txt
int get_ipv6_dns_server(struct in6_addr *dns_server_address, uint32_t *scope_id)
{
PIP_ADAPTER_ADDRESSES addresses = NULL;
PIP_ADAPTER_ADDRESSES address = NULL;
IP_ADAPTER_DNS_SERVER_ADDRESS *dns_server = NULL;
struct sockaddr_in6 *dns_v6_addr = NULL;
ULONG buf_size = INITIAL_DNS_ADDR_BUF_SIZE;
DWORD res = ERROR_BUFFER_OVERFLOW;
int i;
for (i = 0; i < REALLOC_RETRIES; i++) {
// If non null, we hit buffer overflow, free it so we can try again.
if (addresses != NULL) {
g_free(addresses);
}
addresses = g_malloc(buf_size);
res = GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX, NULL,
addresses, &buf_size);
if (res != ERROR_BUFFER_OVERFLOW) {
break;
}
}
if (res != NO_ERROR) {
DEBUG_ERROR("Failed to get IPv6 DNS addresses due to error %lX", res);
goto failure;
}
address = addresses;
for (address = addresses; address != NULL; address = address->Next) {
for (dns_server = address->FirstDnsServerAddress;
dns_server != NULL;
dns_server = dns_server->Next) {
if (dns_server->Address.lpSockaddr->sa_family != AF_INET6) {
continue;
}
dns_v6_addr = (struct sockaddr_in6 *)dns_server->Address.lpSockaddr;
if (is_site_local_dns_broadcast(&dns_v6_addr->sin6_addr) == 0) {
print_dns_v6_address(dns_v6_addr->sin6_addr);
*dns_server_address = dns_v6_addr->sin6_addr;
*scope_id = dns_v6_addr->sin6_scope_id;
g_free(addresses);
return 0;
}
}
}
DEBUG_ERROR("No IPv6 DNS servers found.\n");
failure:
g_free(addresses);
return -1;
}
int get_dns6_addr(struct in6_addr *pdns6_addr, uint32_t *scope_id)
{
if (!in6_zero(&dns6_addr) && (curtime - dns6_addr_time) < TIMEOUT_DEFAULT) {
*pdns6_addr = dns6_addr;
*scope_id = dns6_scope_id;
return 0;
}
if (get_ipv6_dns_server(pdns6_addr, scope_id) == 0) {
dns6_addr = *pdns6_addr;
dns6_addr_time = curtime;
dns6_scope_id = *scope_id;
return 0;
}
return -1;
}
static void winsock_cleanup(void)
{
WSACleanup();
}
#elif defined(__APPLE__)
#include <resolv.h>
static int get_dns_addr_cached(void *pdns_addr, void *cached_addr,
socklen_t addrlen, unsigned *cached_time)
{
if (curtime - *cached_time < TIMEOUT_DEFAULT) {
memcpy(pdns_addr, cached_addr, addrlen);
return 0;
}
return 1;
}
static int get_dns_addr_libresolv(int af, void *pdns_addr, void *cached_addr,
socklen_t addrlen,
uint32_t *scope_id, uint32_t *cached_scope_id,
unsigned *cached_time)
{
struct __res_state state;
union res_sockaddr_union servers[NI_MAXSERV];
int count;
int found;
void *addr;
// we only support IPv4 and IPv4, we assume it's one or the other
assert(af == AF_INET || af == AF_INET6);
if (res_ninit(&state) != 0) {
return -1;
}
count = res_getservers(&state, servers, NI_MAXSERV);
found = 0;
DEBUG_MISC("IP address of your DNS(s):");
for (int i = 0; i < count; i++) {
if (af == servers[i].sin.sin_family) {
found++;
}
if (af == AF_INET) {
addr = &servers[i].sin.sin_addr;
} else { // af == AF_INET6
addr = &servers[i].sin6.sin6_addr;
}
// we use the first found entry
if (found == 1) {
memcpy(pdns_addr, addr, addrlen);
memcpy(cached_addr, addr, addrlen);
if (scope_id) {
*scope_id = 0;
}
if (cached_scope_id) {
*cached_scope_id = 0;
}
*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, addr, s, sizeof(s));
if (!res) {
res = " (string conversion error)";
}
DEBUG_MISC(" %s", res);
}
}
res_ndestroy(&state);
if (!found)
return -1;
return 0;
}
int get_dns_addr(struct in_addr *pdns_addr)
{
if (dns_addr.s_addr != 0) {
int ret;
ret = get_dns_addr_cached(pdns_addr, &dns_addr, sizeof(dns_addr),
&dns_addr_time);
if (ret <= 0) {
return ret;
}
}
return get_dns_addr_libresolv(AF_INET, pdns_addr, &dns_addr,
sizeof(dns_addr), NULL, NULL, &dns_addr_time);
}
int get_dns6_addr(struct in6_addr *pdns6_addr, uint32_t *scope_id)
{
if (!in6_zero(&dns6_addr)) {
int ret;
ret = get_dns_addr_cached(pdns6_addr, &dns6_addr, sizeof(dns6_addr),
&dns6_addr_time);
if (ret == 0) {
*scope_id = dns6_scope_id;
}
if (ret <= 0) {
return ret;
}
}
return get_dns_addr_libresolv(AF_INET6, pdns6_addr, &dns6_addr,
sizeof(dns6_addr),
scope_id, &dns6_scope_id, &dns6_addr_time);
}
#else // !defined(_WIN32) && !defined(__APPLE__)
#if defined(__HAIKU__)
#define RESOLV_CONF_PATH "/boot/system/settings/network/resolv.conf"
#else
#define RESOLV_CONF_PATH "/etc/resolv.conf"
#endif
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(RESOLV_CONF_PATH, 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, uint32_t *cached_scope_id,
unsigned *cached_time)
{
char buff[512];
char buff2[257];
FILE *f;
int found = 0;
union {
struct in_addr dns_addr;
struct in6_addr dns6_addr;
} tmp_addr;
unsigned if_index;
assert(sizeof(tmp_addr) >= addrlen);
f = fopen(RESOLV_CONF_PATH, "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;
}
if (cached_scope_id) {
*cached_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, 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) {
*scope_id = dns6_scope_id;
}
if (ret <= 0) {
return ret;
}
}
return get_dns_addr_resolv_conf(AF_INET6, pdns6_addr, &dns6_addr,
sizeof(dns6_addr),
scope_id, &dns6_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 },
{ "verbose_call", DBG_VERBOSE_CALL },
};
slirp_debug = g_parse_debug_string(debug, keys, G_N_ELEMENTS(keys));
}
}
Slirp *slirp_new(const SlirpConfig *cfg, const SlirpCb *callbacks, void *opaque)
{
Slirp *slirp;
g_return_val_if_fail(cfg != NULL, NULL);
g_return_val_if_fail(cfg->version >= SLIRP_CONFIG_VERSION_MIN, NULL);
g_return_val_if_fail(cfg->version <= SLIRP_CONFIG_VERSION_MAX, NULL);
g_return_val_if_fail(cfg->if_mtu >= IF_MTU_MIN || cfg->if_mtu == 0, NULL);
g_return_val_if_fail(cfg->if_mtu <= IF_MTU_MAX, NULL);
g_return_val_if_fail(cfg->if_mru >= IF_MRU_MIN || cfg->if_mru == 0, NULL);
g_return_val_if_fail(cfg->if_mru <= IF_MRU_MAX, NULL);
g_return_val_if_fail(!cfg->bootfile ||
(strlen(cfg->bootfile) <
G_SIZEOF_MEMBER(struct bootp_t, bp_file)), NULL);
slirp = g_malloc0(sizeof(Slirp));
slirp_init_once();
slirp->opaque = opaque;
slirp->cb = callbacks;
slirp->grand = g_rand_new();
slirp->restricted = cfg->restricted;
slirp->in_enabled = cfg->in_enabled;
slirp->in6_enabled = cfg->in6_enabled;
if_init(slirp);
ip_init(slirp);
ip6_init(slirp);
m_init(slirp);
slirp->vnetwork_addr = cfg->vnetwork;
slirp->vnetwork_mask = cfg->vnetmask;
slirp->vhost_addr = cfg->vhost;
slirp->vprefix_addr6 = cfg->vprefix_addr6;
slirp->vprefix_len = cfg->vprefix_len;
slirp->vhost_addr6 = cfg->vhost6;
if (cfg->vhostname) {
slirp_pstrcpy(slirp->client_hostname, sizeof(slirp->client_hostname),
cfg->vhostname);
}
slirp->tftp_prefix = g_strdup(cfg->tftp_path);
slirp->bootp_filename = g_strdup(cfg->bootfile);
slirp->vdomainname = g_strdup(cfg->vdomainname);
slirp->vdhcp_startaddr = cfg->vdhcp_start;
slirp->vnameserver_addr = cfg->vnameserver;
slirp->vnameserver_addr6 = cfg->vnameserver6;
slirp->tftp_server_name = g_strdup(cfg->tftp_server_name);
if (cfg->vdnssearch) {
translate_dnssearch(slirp, cfg->vdnssearch);
}
slirp->if_mtu = cfg->if_mtu == 0 ? IF_MTU_DEFAULT : cfg->if_mtu;
slirp->if_mru = cfg->if_mru == 0 ? IF_MRU_DEFAULT : cfg->if_mru;
slirp->disable_host_loopback = cfg->disable_host_loopback;
slirp->enable_emu = cfg->enable_emu;
if (cfg->version >= 2) {
slirp->outbound_addr = cfg->outbound_addr;
slirp->outbound_addr6 = cfg->outbound_addr6;
} else {
slirp->outbound_addr = NULL;
slirp->outbound_addr6 = NULL;
}
if (cfg->version >= 3) {
slirp->disable_dns = cfg->disable_dns;
} else {
slirp->disable_dns = false;
}
if (cfg->version >= 4) {
slirp->disable_dhcp = cfg->disable_dhcp;
} else {
slirp->disable_dhcp = false;
}
return slirp;
}
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)
{
SlirpConfig cfg;
memset(&cfg, 0, sizeof(cfg));
cfg.version = 1;
cfg.restricted = restricted;
cfg.in_enabled = in_enabled;
cfg.vnetwork = vnetwork;
cfg.vnetmask = vnetmask;
cfg.vhost = vhost;
cfg.in6_enabled = in6_enabled;
cfg.vprefix_addr6 = vprefix_addr6;
cfg.vprefix_len = vprefix_len;
cfg.vhost6 = vhost6;
cfg.vhostname = vhostname;
cfg.tftp_server_name = tftp_server_name;
cfg.tftp_path = tftp_path;
cfg.bootfile = bootfile;
cfg.vdhcp_start = vdhcp_start;
cfg.vnameserver = vnameserver;
cfg.vnameserver6 = vnameserver6;
cfg.vdnssearch = vdnssearch;
cfg.vdomainname = vdomainname;
return slirp_new(&cfg, callbacks, opaque);
}
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->ex_unix);
g_free(e);
}
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.
*
* If sb is already half full, we will wait for the guest to consume it,
* and notify again in sbdrop() when the sb becomes less than half full.
*/
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;
}
#ifndef __APPLE__
/*
* Check for URG data
* This will soread as well, so no need to
* test for SLIRP_POLL_IN below if this succeeds.
*
* This is however disabled on MacOS, which apparently always
* reports data as PRI when it is the last data of the
* connection. We would then report it out of band, which the guest
* would most probably not be ready for.
*/
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
#endif
if (revents &
(SLIRP_POLL_IN | SLIRP_POLL_HUP | SLIRP_POLL_ERR | SLIRP_POLL_PRI)) {
/*
* 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)
{
const struct slirp_arphdr *ah =
(const 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;
}
if (pkt_len < ETH_HLEN + sizeof(struct slirp_arphdr)) {
return; /* packet too short */
}
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;
/* TODO: IPv6 */
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 (!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[IF_MTU_MAX + 100];
struct ethhdr *eh = (struct ethhdr *)buf;
uint8_t ethaddr[ETH_ALEN];
const struct ip *iph = (const struct ip *)ifm->m_data;
int ret;
char ethaddr_str[ETH_ADDRSTRLEN];
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();
}
memcpy(eh->h_dest, ethaddr, ETH_ALEN);
DEBUG_ARG("src = %s", slirp_ether_ntoa(eh->h_source, ethaddr_str,
sizeof(ethaddr_str)));
DEBUG_ARG("dst = %s", slirp_ether_ntoa(eh->h_dest, ethaddr_str,
sizeof(ethaddr_str)));
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_len == sizeof(addr) &&
addr.sin_family == AF_INET &&
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;
}
int slirp_remove_hostxfwd(Slirp *slirp,
const struct sockaddr *haddr, socklen_t haddrlen,
int flags)
{
struct socket *so;
struct socket *head = (flags & SLIRP_HOSTFWD_UDP ? &slirp->udb : &slirp->tcb);
struct sockaddr_storage addr;
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 &&
sockaddr_equal(&addr, (const struct sockaddr_storage *) haddr)) {
so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
closesocket(so->s);
sofree(so);
return 0;
}
}
return -1;
}
int slirp_add_hostxfwd(Slirp *slirp,
const struct sockaddr *haddr, socklen_t haddrlen,
const struct sockaddr *gaddr, socklen_t gaddrlen,
int flags)
{
struct sockaddr_in gdhcp_addr;
int fwd_flags = SS_HOSTFWD;
if (flags & SLIRP_HOSTFWD_V6ONLY)
fwd_flags |= SS_HOSTFWD_V6ONLY;
if (gaddr->sa_family == AF_INET) {
const struct sockaddr_in *gaddr_in = (const struct sockaddr_in *) gaddr;
if (gaddrlen < sizeof(struct sockaddr_in)) {
errno = EINVAL;
return -1;
}
if (!gaddr_in->sin_addr.s_addr) {
gdhcp_addr = *gaddr_in;
gdhcp_addr.sin_addr = slirp->vdhcp_startaddr;
gaddr = (struct sockaddr *) &gdhcp_addr;
gaddrlen = sizeof(gdhcp_addr);
}
} else {
if (gaddrlen < sizeof(struct sockaddr_in6)) {
errno = EINVAL;
return -1;
}
/*
* Libslirp currently only provides a stateless DHCPv6 server, thus
* we can't translate "addr-any" to the guest here. Instead, we defer
* performing the translation to when it's needed. See
* soassign_guest_addr_if_needed().
*/
}
if (flags & SLIRP_HOSTFWD_UDP) {
if (!udpx_listen(slirp, haddr, haddrlen,
gaddr, gaddrlen,
fwd_flags))
return -1;
} else {
if (!tcpx_listen(slirp, haddr, haddrlen,
gaddr, gaddrlen,
fwd_flags))
return -1;
}
return 0;
}
/* TODO: IPv6 */
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_unix(Slirp *slirp, const char *unixsock,
struct in_addr *guest_addr, int guest_port)
{
#ifdef G_OS_UNIX
if (!check_guestfwd(slirp, guest_addr, guest_port)) {
return -1;
}
add_unix(&slirp->guestfwd_list, unixsock, *guest_addr, htons(guest_port));
return 0;
#else
g_warn_if_reached();
return -1;
#endif
}
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;
}
int slirp_remove_guestfwd(Slirp *slirp, struct in_addr guest_addr,
int guest_port)
{
return remove_guestfwd(&slirp->guestfwd_list, guest_addr,
htons(guest_port));
}
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;
/* TODO: IPv6 */
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)) {
/* If the sb is already half full, we will wait for the guest to consume it,
* and notify again in sbdrop() when the sb becomes less than half full. */
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);
}
}