dhcpd.h

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/*      dhcpd.h - Dynamic Host Configuration Protocol daemon.
 *                                                      Author: Kees J. Bot
 *                                                              16 Dec 2000
 */

#define nil ((void*)0)

#include <minix/paths.h>

/* Paths to files. */
#define PATH_DHCPCONF   _PATH_DHCPCONF
#define PATH_DHCPPID    _PATH_DHCPPID
#define PATH_DHCPCACHE  _PATH_DHCPCACHE
#define PATH_DHCPPOOL   _PATH_DHCPPOOL

#define CLID_MAX        32      /* Maximum client ID length. */

#ifndef EXTERN
#define EXTERN  extern
#endif

EXTERN char *program;           /* This program's name. */
extern char *configfile;        /* Configuration file. */
extern char *poolfile;          /* Dynamic address pool. */
EXTERN int serving;             /* True if being a DHCP server. */
EXTERN unsigned test;           /* Test level. */
EXTERN unsigned debug;          /* Debug level. */
EXTERN asynchio_t asyn;         /* Bookkeeping for all async I/O. */

/* BOOTP UDP ports:  (That they are different is quite stupid.) */
EXTERN u16_t port_server;       /* Port server listens on. */
EXTERN u16_t port_client;       /* Port client listens on. */

#define arraysize(a)    (sizeof(a) / sizeof((a)[0]))
#define arraylimit(a)   ((a) + arraysize(a))
#define between(a,c,z)  (sizeof(c) <= sizeof(unsigned) ? \
        (unsigned) (c) - (a) <= (unsigned) (z) - (a) : \
        (unsigned long) (c) - (a) <= (unsigned long) (z) - (a))

/* To treat objects as octet arrays: */
#define B(a)            ((u8_t *) (a))

/* Times. */
EXTERN time_t start, now;               /* Start and current time. */
EXTERN time_t event;                    /* Time of the next timed event. */

/* Special times and periods: */
#define NEVER   (sizeof(time_t) <= sizeof(int) ? INT_MAX : LONG_MAX)
#define DELTA_FIRST                4    /* Between first and second query. */
#define DELTA_FAST                64    /* Unbound queries this often. */
#define DELTA_SLOW               512    /* Bound queries are more relaxed. */
#define N_SOLICITS                 3    /* Number of solicitations. */
#define DELTA_SOL                  3    /* Time between solicitations. */
#define DELTA_ADV               2048    /* Router adverts to self lifetime. */

/* Buffers for packets. */
typedef struct buf {
        eth_hdr_t       *eth;           /* Ethernet header in payload. */
        ip_hdr_t        *ip;            /* IP header in payload. */
        udp_hdr_t       *udp;           /* UDP header in payload. */
        udp_io_hdr_t    *udpio;         /* UDP I/O header in payload. */
        dhcp_t          *dhcp;          /* DHCP data in payload. */
        u8_t            pad[2];         /* buf[] must start at 2 mod 4. */
                                        /* Payload: */
        u8_t            buf[ETH_MAX_PACK_SIZE];
} buf_t;

#define BUF_ETH_SIZE    (ETH_MAX_PACK_SIZE)
#define BUF_IP_SIZE     (BUF_ETH_SIZE - sizeof(eth_hdr_t))
#define BUF_UDP_SIZE    (BUF_IP_SIZE - sizeof(ip_hdr_t) - sizeof(udp_hdr_t) \
                                + sizeof(udp_io_hdr_t))

/* Type of network device open: Ethernet, ICMP, BOOTP client, BOOTP server. */
typedef enum { FT_CLOSED, FT_ETHERNET, FT_ICMP, FT_BOOTPC, FT_BOOTPS } fdtype_t;

#define FT_ALL  FT_CLOSED       /* To close all open descriptors at once. */

typedef struct fd {             /* An open descriptor. */
        i8_t            fd;             /* Open descriptor. */
        u8_t            fdtype;         /* Type of network open. */
        char            device[sizeof("/dev/eth###")];  /* Device name. */
        u8_t            n;              /* Network that owns it. */
        buf_t           *bp;            /* Associated packet buffer. */
        time_t          since;          /* Open since when? */
} fd_t;

/* Network state: Any IP device, Ethernet in sink mode, True Ethernet. */
typedef enum { NT_IP, NT_SINK, NT_ETHERNET } nettype_t;

typedef struct network {        /* Information on a network. */
        u8_t            n;              /* Network number. */
        ether_addr_t    eth;            /* Ethernet address of this net. */
        u8_t            type;           /* What kind of net is this? */
        i8_t            sol_ct;         /* Router solicitation count. */
        ether_addr_t    conflict;       /* Address conflict with this one. */
        unsigned        flags;          /* Various flags. */
        fd_t            *fdp;           /* Current open device. */
        struct network  *wait;          /* Wait for a resource list. */
        ipaddr_t        ip;             /* IP address of this net. */
        ipaddr_t        mask;           /* Associated netmask. */
        ipaddr_t        gateway;        /* My router. */
        ipaddr_t        server;         /* My DHCP server. */
        const char      *hostname;      /* Optional hostname to query for. */
        time_t          start;          /* Query or lease start time. */
        time_t          delta;          /* Query again after delta seconds. */
        time_t          renew;          /* Next query or go into renewal. */
        time_t          rebind;         /* When to go into rebind. */
        time_t          lease;          /* When our lease expires. */
        time_t          solicit;        /* Time to do a router solicitation. */
} network_t;

/* Flags. */
#define NF_NEGOTIATING  0x001           /* Negotiating with a DHCP server. */
#define NF_BOUND        0x002           /* Address configured through DHCP. */
#define NF_SERVING      0x004           /* I'm a server on this network. */
#define NF_RELAYING     0x008           /* I'm relaying for this network. */
#define NF_WAIT         0x010           /* Wait for a resource to free up. */
#define NF_IRDP         0x020           /* IRDP is used on this net. */
#define NF_CONFLICT     0x040           /* There is an address conflict. */
#define NF_POSSESSIVE   0x080           /* Keep address if lease expires. */
#define NF_INFORM       0x100           /* It's ok to answer DHCPINFORM. */

/* Functions defined in dhcpd.c. */
void report(const char *label);
void fatal(const char *label);
void *allocate(size_t size);
int ifname2if(const char *name);
network_t *if2net(int n);

/* Devices.c */
void get_buf(buf_t **bp);
void put_buf(buf_t **bp);
void give_buf(buf_t **dbp, buf_t **sbp);
network_t *newnetwork(void);
void closefd(fd_t *fdp);
int opendev(network_t *np, fdtype_t fdtype, int compete);
void closedev(network_t *np, fdtype_t fdtype);
char *ipdev(int n);
void set_ipconf(char *device, ipaddr_t ip, ipaddr_t mask, unsigned mtu);

/* Ether.c */
void udp2ether(buf_t *bp, network_t *np);
int ether2udp(buf_t *bp);
void make_arp(buf_t *bp, network_t *np);
int is_arp_me(buf_t *bp, network_t *np);
void icmp_solicit(buf_t *bp);
void icmp_advert(buf_t *bp, network_t *np);
ipaddr_t icmp_is_advert(buf_t *bp);

/* Tags.c */
#define gettag(dp, st, pd, pl)  dhcp_gettag((dp), (st), (pd), (pl))
void settag(dhcp_t *dp, int tag, void *data, size_t len);
char *cidr_ntoa(ipaddr_t addr, ipaddr_t mask);
void ether2clid(u8_t *clid, ether_addr_t *eth);
void initdhcpconf(void);
int makedhcp(dhcp_t *dp, u8_t *class, size_t calen, u8_t *client, size_t cilen,
                                ipaddr_t ip, ipaddr_t ifip, network_t *np);
char *dhcptypename(int type);
void printdhcp(dhcp_t *dp);

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