void slirp_input(const uint8_t *pkt, int pkt_len)
{
struct mbuf *m;
int proto;
if (pkt_len < ETH_HLEN)
return;
proto = ntohs(*(uint16_t *)(pkt + 12));
switch(proto) {
case ETH_P_ARP:
arp_input(pkt, pkt_len);
break;
case ETH_P_IP:
m = m_get();
if (!m)
return;
if (M_FREEROOM(m) < pkt_len + 2) {
m_inc(m, pkt_len + 2);
}
m->m_len = pkt_len + 2;
memcpy(m->m_data + 2, pkt, pkt_len);
m->m_data += 2 + ETH_HLEN;
m->m_len -= 2 + ETH_HLEN;
ip_input(m);
break;
default:
break;
}
}
void
m_cat(struct mbuf *m, struct mbuf *n)
{
if (M_FREEROOM(m) < n->m_len)
m_inc(m,m->m_size+MINCSIZE);
memcpy(m->m_data+m->m_len, n->m_data, n->m_len);
m->m_len += n->m_len;
m_free(n);
}
/*
* Copy data from one mbuf to the end of
* the other.. if result is too big for one mbuf, malloc()
* an M_EXT data segment
*/
void
m_cat(struct mbuf *m, struct mbuf *n)
{
/*
* If there's no room, realloc
*/
if (M_FREEROOM(m) < n->m_len)
m_inc(m,m->m_size+MINCSIZE);
memcpy(m->m_data+m->m_len, n->m_data, n->m_len);
m->m_len += n->m_len;
m_free(n);
}
/*
* recvfrom() a UDP socket
*/
void
sorecvfrom(struct socket *so)
{
struct sockaddr_in addr;
socklen_t addrlen = sizeof(struct sockaddr_in);
DEBUG_CALL("sorecvfrom");
DEBUG_ARG("so = %lx", (long)so);
if (so->so_type == IPPROTO_ICMP) { /* This is a "ping" reply */
char buff[256];
int len;
len = recvfrom(so->s, buff, 256, 0,
(struct sockaddr *)&addr, &addrlen);
/* XXX Check if reply is "correct"? */
if(len == -1 || len == 0) {
u_char code=ICMP_UNREACH_PORT;
if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
else if(errno == ENETUNREACH) code=ICMP_UNREACH_NET;
DEBUG_MISC((dfd," udp icmp rx errno = %d-%s\n",
errno,strerror(errno)));
icmp_error(so->so_m, ICMP_UNREACH,code, 0,strerror(errno));
} else {
icmp_reflect(so->so_m);
so->so_m = NULL; /* Don't m_free() it again! */
}
/* No need for this socket anymore, udp_detach it */
udp_detach(so);
} else { /* A "normal" UDP packet */
struct mbuf *m;
int len;
#ifdef _WIN32
unsigned long n;
#else
int n;
#endif
m = m_get(so->slirp);
if (!m) {
return;
}
m->m_data += IF_MAXLINKHDR;
/*
* XXX Shouldn't FIONREAD packets destined for port 53,
* but I don't know the max packet size for DNS lookups
*/
len = M_FREEROOM(m);
/* if (so->so_fport != htons(53)) { */
ioctlsocket(so->s, FIONREAD, &n);
if (n > len) {
n = (m->m_data - m->m_dat) + m->m_len + n + 1;
m_inc(m, n);
len = M_FREEROOM(m);
}
/* } */
m->m_len = recvfrom(so->s, m->m_data, len, 0,
(struct sockaddr *)&addr, &addrlen);
DEBUG_MISC((dfd, " did recvfrom %d, errno = %d-%s\n",
m->m_len, errno,strerror(errno)));
if(m->m_len<0) {
u_char code=ICMP_UNREACH_PORT;
if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
else if(errno == ENETUNREACH) code=ICMP_UNREACH_NET;
DEBUG_MISC((dfd," rx error, tx icmp ICMP_UNREACH:%i\n", code));
icmp_error(so->so_m, ICMP_UNREACH,code, 0,strerror(errno));
m_free(m);
} else {
/*
* Hack: domain name lookup will be used the most for UDP,
* and since they'll only be used once there's no need
* for the 4 minute (or whatever) timeout... So we time them
* out much quicker (10 seconds for now...)
*/
if (so->so_expire) {
if (so->so_fport == htons(53))
so->so_expire = curtime + SO_EXPIREFAST;
else
so->so_expire = curtime + SO_EXPIRE;
}
/*
* If this packet was destined for CTL_ADDR,
* make it look like that's where it came from, done by udp_output
*/
udp_output(so, m, &addr);
} /* rx error */
} /* if ping packet */
}
void
icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
const char *message)
{
unsigned hlen, shlen, s_ip_len;
register struct ip *ip;
register struct icmp *icp;
register struct mbuf *m;
DEBUG_CALL("icmp_error");
DEBUG_ARG("msrc = %lx", (long )msrc);
DEBUG_ARG("msrc_len = %d", msrc->m_len);
if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error;
/* check msrc */
if(!msrc) goto end_error;
ip = mtod(msrc, struct ip *);
#ifdef DEBUG
{ char bufa[20], bufb[20];
strcpy(bufa, inet_ntoa(ip->ip_src));
strcpy(bufb, inet_ntoa(ip->ip_dst));
DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
}
#endif
if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */
/* Do not reply to source-only IPs */
if ((ip->ip_src.s_addr & htonl(~(0xf << 28))) == 0) {
goto end_error;
}
shlen=ip->ip_hl << 2;
s_ip_len=ip->ip_len;
if(ip->ip_p == IPPROTO_ICMP) {
icp = (struct icmp *)((char *)ip + shlen);
/*
* Assume any unknown ICMP type is an error. This isn't
* specified by the RFC, but think about it..
*/
if(icp->icmp_type>18 || icmp_flush[icp->icmp_type]) goto end_error;
}
/* make a copy */
m = m_get(msrc->slirp);
if (!m) {
goto end_error;
}
{ int new_m_size;
new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN;
if(new_m_size>m->m_size) m_inc(m, new_m_size);
}
memcpy(m->m_data, msrc->m_data, msrc->m_len);
m->m_len = msrc->m_len; /* copy msrc to m */
/* make the header of the reply packet */
ip = mtod(m, struct ip *);
hlen= sizeof(struct ip ); /* no options in reply */
/* fill in icmp */
m->m_data += hlen;
m->m_len -= hlen;
icp = mtod(m, struct icmp *);
if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */
else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */
s_ip_len=ICMP_MAXDATALEN;
m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */
/* min. size = 8+sizeof(struct ip)+8 */
icp->icmp_type = type;
icp->icmp_code = code;
icp->icmp_id = 0;
icp->icmp_seq = 0;
memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
HTONS(icp->icmp_ip.ip_len);
HTONS(icp->icmp_ip.ip_id);
HTONS(icp->icmp_ip.ip_off);
#ifdef DEBUG
if(message) { /* DEBUG : append message to ICMP packet */
int message_len;
char *cpnt;
message_len=strlen(message);
if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN;
cpnt=(char *)m->m_data+m->m_len;
memcpy(cpnt, message, message_len);
m->m_len+=message_len;
}
#endif
icp->icmp_cksum = 0;
icp->icmp_cksum = cksum(m, m->m_len);
m->m_data -= hlen;
m->m_len += hlen;
/* fill in ip */
ip->ip_hl = hlen >> 2;
ip->ip_len = m->m_len;
ip->ip_tos=((ip->ip_tos & 0x1E) | 0xC0); /* high priority for errors */
ip->ip_ttl = MAXTTL;
ip->ip_p = IPPROTO_ICMP;
ip->ip_dst = ip->ip_src; /* ip adresses */
ip->ip_src = m->slirp->vhost_addr;
(void ) ip_output((struct socket *)NULL, m);
end_error:
return;
}
self & operator++() { m_inc(); return *this; }
/*
* recvfrom() a UDP socket
*/
void
sorecvfrom(struct socket *so)
{
struct sockaddr_storage addr;
struct sockaddr_storage saddr, daddr;
socklen_t addrlen = sizeof(struct sockaddr_storage);
DEBUG_CALL("sorecvfrom");
DEBUG_ARG("so = %p", so);
if (so->so_type == IPPROTO_ICMP) { /* This is a "ping" reply */
char buff[256];
int len;
len = recvfrom(so->s, buff, 256, 0,
(struct sockaddr *)&addr, &addrlen);
/* XXX Check if reply is "correct"? */
if(len == -1 || len == 0) {
u_char code=ICMP_UNREACH_PORT;
if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
else if(errno == ENETUNREACH) code=ICMP_UNREACH_NET;
DEBUG_MISC((dfd," udp icmp rx errno = %d-%s\n",
errno,strerror(errno)));
icmp_send_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno));
} else {
icmp_reflect(so->so_m);
so->so_m = NULL; /* Don't m_free() it again! */
}
/* No need for this socket anymore, udp_detach it */
udp_detach(so);
} else { /* A "normal" UDP packet */
struct mbuf *m;
int len;
#ifdef _WIN32
unsigned long n;
#else
int n;
#endif
m = m_get(so->slirp);
if (!m) {
return;
}
switch (so->so_ffamily) {
case AF_INET:
m->m_data += IF_MAXLINKHDR + sizeof(struct udpiphdr);
break;
case AF_INET6:
m->m_data += IF_MAXLINKHDR + sizeof(struct ip6)
+ sizeof(struct udphdr);
break;
default:
g_assert_not_reached();
break;
}
/*
* XXX Shouldn't FIONREAD packets destined for port 53,
* but I don't know the max packet size for DNS lookups
*/
len = M_FREEROOM(m);
/* if (so->so_fport != htons(53)) { */
ioctlsocket(so->s, FIONREAD, &n);
if (n > len) {
n = (m->m_data - m->m_dat) + m->m_len + n + 1;
m_inc(m, n);
len = M_FREEROOM(m);
}
/* } */
m->m_len = recvfrom(so->s, m->m_data, len, 0,
(struct sockaddr *)&addr, &addrlen);
DEBUG_MISC((dfd, " did recvfrom %d, errno = %d-%s\n",
m->m_len, errno,strerror(errno)));
if(m->m_len<0) {
/* Report error as ICMP */
switch (so->so_lfamily) {
uint8_t code;
case AF_INET:
code = ICMP_UNREACH_PORT;
if (errno == EHOSTUNREACH) {
code = ICMP_UNREACH_HOST;
} else if (errno == ENETUNREACH) {
code = ICMP_UNREACH_NET;
}
DEBUG_MISC((dfd, " rx error, tx icmp ICMP_UNREACH:%i\n", code));
icmp_send_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno));
break;
case AF_INET6:
code = ICMP6_UNREACH_PORT;
if (errno == EHOSTUNREACH) {
code = ICMP6_UNREACH_ADDRESS;
} else if (errno == ENETUNREACH) {
code = ICMP6_UNREACH_NO_ROUTE;
}
DEBUG_MISC((dfd, " rx error, tx icmp6 ICMP_UNREACH:%i\n", code));
icmp6_send_error(so->so_m, ICMP6_UNREACH, code);
break;
default:
g_assert_not_reached();
break;
}
m_free(m);
} else {
/*
* Hack: domain name lookup will be used the most for UDP,
* and since they'll only be used once there's no need
* for the 4 minute (or whatever) timeout... So we time them
* out much quicker (10 seconds for now...)
*/
if (so->so_expire) {
if (so->so_fport == htons(53))
so->so_expire = curtime + SO_EXPIREFAST;
else
so->so_expire = curtime + SO_EXPIRE;
}
/*
* If this packet was destined for CTL_ADDR,
* make it look like that's where it came from
*/
saddr = addr;
sotranslate_in(so, &saddr);
daddr = so->lhost.ss;
switch (so->so_ffamily) {
case AF_INET:
udp_output(so, m, (struct sockaddr_in *) &saddr,
(struct sockaddr_in *) &daddr,
so->so_iptos);
break;
case AF_INET6:
udp6_output(so, m, (struct sockaddr_in6 *) &saddr,
(struct sockaddr_in6 *) &daddr);
break;
default:
g_assert_not_reached();
break;
}
} /* rx error */
} /* if ping packet */
}