src/slirp.h

/* SPDX-License-Identifier: BSD-3-Clause */
#ifndef SLIRP_H
#define SLIRP_H

#ifdef _WIN32

/* as defined in sdkddkver.h */
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0600 /* Vista */
#endif
/* reduces the number of implicitly included headers */
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#include <sys/timeb.h>
#include <iphlpapi.h>

#else
#define O_BINARY 0
#endif

#ifndef _WIN32
#include <sys/uio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#endif

#ifdef __APPLE__
#include <sys/filio.h>
#endif

#include "debug.h"
#include "util.h"

#include "libslirp.h"
#include "ip.h"
#include "ip6.h"
#include "tcp.h"
#include "tcp_timer.h"
#include "tcp_var.h"
#include "tcpip.h"
#include "udp.h"
#include "ip_icmp.h"
#include "ip6_icmp.h"
#include "mbuf.h"
#include "sbuf.h"
#include "socket.h"
#include "if.h"
#include "main.h"
#include "misc.h"

#include "bootp.h"
#include "tftp.h"

#define ARPOP_REQUEST 1 /* ARP request */
#define ARPOP_REPLY 2 /* ARP reply   */

struct ethhdr {
    unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
    unsigned char h_source[ETH_ALEN]; /* source ether addr    */
    unsigned short h_proto; /* packet type ID field */
};

struct slirp_arphdr {
    unsigned short ar_hrd; /* format of hardware address */
    unsigned short ar_pro; /* format of protocol address */
    unsigned char ar_hln; /* length of hardware address */
    unsigned char ar_pln; /* length of protocol address */
    unsigned short ar_op; /* ARP opcode (command)       */

    /*
     *  Ethernet looks like this : This bit is variable sized however...
     */
    uint8_t ar_sha[ETH_ALEN]; /* sender hardware address */
    uint32_t ar_sip; /* sender IP address       */
    uint8_t ar_tha[ETH_ALEN]; /* target hardware address */
    uint32_t ar_tip; /* target IP address       */
} SLIRP_PACKED;

#define ARP_TABLE_SIZE 16

typedef struct ArpTable {
    struct slirp_arphdr table[ARP_TABLE_SIZE];
    int next_victim;
} ArpTable;

void arp_table_add(Slirp *slirp, uint32_t ip_addr,
                   const uint8_t ethaddr[ETH_ALEN]);

bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
                      uint8_t out_ethaddr[ETH_ALEN]);

struct ndpentry {
    uint8_t eth_addr[ETH_ALEN]; /* sender hardware address */
    struct in6_addr ip_addr; /* sender IP address       */
};

#define NDP_TABLE_SIZE 16

typedef struct NdpTable {
    struct ndpentry table[NDP_TABLE_SIZE];
    /*
     * The table is a cache with old entries overwritten when the table fills.
     * Preserve the first entry: it is the guest, which is needed for lazy
     * hostfwd guest address assignment.
     */
    struct in6_addr guest_in6_addr;
    int next_victim;
} NdpTable;

void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
                   uint8_t ethaddr[ETH_ALEN]);
bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
                      uint8_t out_ethaddr[ETH_ALEN]);

struct Slirp {
    int cfg_version;

    unsigned time_fasttimo;
    unsigned last_slowtimo;
    bool do_slowtimo;

    bool in_enabled, in6_enabled;

    /* virtual network configuration */
    struct in_addr vnetwork_addr;
    struct in_addr vnetwork_mask;
    struct in_addr vhost_addr;
    struct in6_addr vprefix_addr6;
    uint8_t vprefix_len;
    struct in6_addr vhost_addr6;
    bool disable_dhcp; /* slirp will not reply to any DHCP requests */
    struct in_addr vdhcp_startaddr;
    struct in_addr vnameserver_addr;
    struct in6_addr vnameserver_addr6;

    struct in_addr client_ipaddr;
    char client_hostname[33];

    int restricted;
    struct gfwd_list *guestfwd_list;

    int if_mtu;
    int if_mru;

    bool disable_host_loopback;

    /* mbuf states */
    struct slirp_quehead m_freelist;
    struct slirp_quehead m_usedlist;
    int mbuf_alloced;

    /* if states */
    struct slirp_quehead if_fastq; /* fast queue (for interactive data) */
    struct slirp_quehead if_batchq; /* queue for non-interactive data */
    bool if_start_busy; /* avoid if_start recursion */

    /* ip states */
    struct ipq ipq; /* ip reass. queue */
    uint16_t ip_id; /* ip packet ctr, for ids */

    /* bootp/dhcp states */
    BOOTPClient bootp_clients[NB_BOOTP_CLIENTS];
    char *bootp_filename;
    size_t vdnssearch_len;
    uint8_t *vdnssearch;
    char *vdomainname;

    /* tcp states */
    struct socket tcb;
    struct socket *tcp_last_so;
    tcp_seq tcp_iss; /* tcp initial send seq # */
    uint32_t tcp_now; /* for RFC 1323 timestamps */

    /* udp states */
    struct socket udb;
    struct socket *udp_last_so;

    /* icmp states */
    struct socket icmp;
    struct socket *icmp_last_so;

    /* tftp states */
    char *tftp_prefix;
    struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
    char *tftp_server_name;

    ArpTable arp_table;
    NdpTable ndp_table;

    GRand *grand;
    void *ra_timer;

    bool enable_emu;

    const SlirpCb *cb;
    void *opaque;

    struct sockaddr_in *outbound_addr;
    struct sockaddr_in6 *outbound_addr6;
    bool disable_dns; /* slirp will not redirect/serve any DNS packet */
};

void if_start(Slirp *);

int get_dns_addr(struct in_addr *pdns_addr);
int get_dns6_addr(struct in6_addr *pdns6_addr, uint32_t *scope_id);

/* ncsi.c */
void ncsi_input(Slirp *slirp, const uint8_t *pkt, int pkt_len);

#ifndef _WIN32
#include <netdb.h>
#endif


extern bool slirp_do_keepalive;

#define TCP_MAXIDLE (TCPTV_KEEPCNT * TCPTV_KEEPINTVL)

/* dnssearch.c */
int translate_dnssearch(Slirp *s, const char **names);

/* cksum.c */
int cksum(struct mbuf *m, int len);
int ip6_cksum(struct mbuf *m);

/* if.c */
void if_init(Slirp *);
void if_output(struct socket *, struct mbuf *);

/* ip_input.c */
void ip_init(Slirp *);
void ip_cleanup(Slirp *);
void ip_input(struct mbuf *);
void ip_slowtimo(Slirp *);
void ip_stripoptions(register struct mbuf *, struct mbuf *);

/* ip_output.c */
int ip_output(struct socket *, struct mbuf *);

/* ip6_input.c */
void ip6_post_init(Slirp *);
void ip6_cleanup(Slirp *);
void ip6_input(struct mbuf *);

/* ip6_output */
int ip6_output(struct socket *, struct mbuf *, int fast);

/* tcp_input.c */
void tcp_input(register struct mbuf *, int, struct socket *, unsigned short af);
int tcp_mss(register struct tcpcb *, unsigned);

/* tcp_output.c */
int tcp_output(register struct tcpcb *);
void tcp_setpersist(register struct tcpcb *);

/* tcp_subr.c */
void tcp_init(Slirp *);
void tcp_cleanup(Slirp *);
void tcp_template(struct tcpcb *);
void tcp_respond(struct tcpcb *, register struct tcpiphdr *,
                 register struct mbuf *, tcp_seq, tcp_seq, int, unsigned short);
struct tcpcb *tcp_newtcpcb(struct socket *);
struct tcpcb *tcp_close(register struct tcpcb *);
void tcp_sockclosed(struct tcpcb *);
int tcp_fconnect(struct socket *, unsigned short af);
void tcp_connect(struct socket *);
void tcp_attach(struct socket *);
uint8_t tcp_tos(struct socket *);
int tcp_emu(struct socket *, struct mbuf *);
int tcp_ctl(struct socket *);
struct tcpcb *tcp_drop(struct tcpcb *tp, int err);

struct socket *slirp_find_ctl_socket(Slirp *slirp, struct in_addr guest_addr,
                                     int guest_port);

void slirp_send_packet_all(Slirp *slirp, const void *buf, size_t len);
void *slirp_timer_new(Slirp *slirp, SlirpTimerId id, void *cb_opaque);

#endif