commands/dhcpd/dhcpd.h

   1 /*      dhcpd.h - Dynamic Host Configuration Protocol daemon.
   2  *                                                      Author: Kees J. Bot
   3  *                                                              16 Dec 2000
   4  */
   5
   6 #define nil ((void*)0)
   7
   8 #include <paths.h>
   9
  10 /* Paths to files. */
  11 #define PATH_DHCPCONF   _PATH_DHCPCONF
  12 #define PATH_DHCPPID    _PATH_DHCPPID
  13 #define PATH_DHCPCACHE  _PATH_DHCPCACHE
  14 #define PATH_DHCPPOOL   _PATH_DHCPPOOL
  15
  16 #define CLID_MAX        32      /* Maximum client ID length. */
  17
  18 #ifndef EXTERN
  19 #define EXTERN  extern
  20 #endif
  21
  22 extern int lwip;
  23
  24 EXTERN char *program;           /* This program's name. */
  25 extern char *configfile;        /* Configuration file. */
  26 extern char *poolfile;          /* Dynamic address pool. */
  27 EXTERN int serving;             /* True if being a DHCP server. */
  28 EXTERN unsigned test;           /* Test level. */
  29 EXTERN unsigned debug;          /* Debug level. */
  30 EXTERN asynchio_t asyn;         /* Bookkeeping for all async I/O. */
  31
  32 /* BOOTP UDP ports:  (That they are different is quite stupid.) */
  33 EXTERN u16_t port_server;       /* Port server listens on. */
  34 EXTERN u16_t port_client;       /* Port client listens on. */
  35
  36 #define arraysize(a)    (sizeof(a) / sizeof((a)[0]))
  37 #define arraylimit(a)   ((a) + arraysize(a))
  38 #define between(a,c,z)  (sizeof(c) <= sizeof(unsigned) ? \
  39         (unsigned) (c) - (a) <= (unsigned) (z) - (a) : \
  40         (unsigned long) (c) - (a) <= (unsigned long) (z) - (a))
  41
  42 /* To treat objects as octet arrays: */
  43 #define B(a)            ((u8_t *) (a))
  44
  45 /* Times. */
  46 EXTERN time_t start, now;               /* Start and current time. */
  47 EXTERN time_t event;                    /* Time of the next timed event. */
  48
  49 /* Special times and periods: */
  50 #define NEVER   (sizeof(time_t) <= sizeof(int) ? INT_MAX : LONG_MAX)
  51 #define DELTA_FIRST                4    /* Between first and second query. */
  52 #define DELTA_FAST                64    /* Unbound queries this often. */
  53 #define DELTA_SLOW               512    /* Bound queries are more relaxed. */
  54 #define N_SOLICITS                 3    /* Number of solicitations. */
  55 #define DELTA_SOL                  3    /* Time between solicitations. */
  56 #define DELTA_ADV               2048    /* Router adverts to self lifetime. */
  57
  58 /* Buffers for packets. */
  59 typedef struct buf {
  60         eth_hdr_t       *eth;           /* Ethernet header in payload. */
  61         ip_hdr_t        *ip;            /* IP header in payload. */
  62         udp_hdr_t       *udp;           /* UDP header in payload. */
  63         udp_io_hdr_t    *udpio;         /* UDP I/O header in payload. */
  64         dhcp_t          *dhcp;          /* DHCP data in payload. */
  65         u8_t            pad[2];         /* buf[] must start at 2 mod 4. */
  66                                         /* Payload: */
  67         u8_t            buf[ETH_MAX_PACK_SIZE];
  68 } buf_t;
  69
  70 #define BUF_ETH_SIZE    (ETH_MAX_PACK_SIZE)
  71 #define BUF_IP_SIZE     (BUF_ETH_SIZE - sizeof(eth_hdr_t))
  72 #define BUF_UDP_SIZE    (BUF_IP_SIZE - sizeof(ip_hdr_t) - sizeof(udp_hdr_t) \
  73                                 + sizeof(udp_io_hdr_t))
  74
  75 /* Type of network device open: Ethernet, ICMP, BOOTP client, BOOTP server. */
  76 typedef enum { FT_CLOSED, FT_ETHERNET, FT_ICMP, FT_BOOTPC, FT_BOOTPS } fdtype_t;
  77
  78 #define FT_ALL  FT_CLOSED       /* To close all open descriptors at once. */
  79
  80 typedef struct fd {             /* An open descriptor. */
  81         i8_t            fd;             /* Open descriptor. */
  82         u8_t            fdtype;         /* Type of network open. */
  83         char            device[sizeof("/dev/eth###")];  /* Device name. */
  84         u8_t            n;              /* Network that owns it. */
  85         buf_t           *bp;            /* Associated packet buffer. */
  86         time_t          since;          /* Open since when? */
  87 } fd_t;
  88
  89 /* Network state: Any IP device, Ethernet in sink mode, True Ethernet. */
  90 typedef enum { NT_IP, NT_SINK, NT_ETHERNET } nettype_t;
  91
  92 typedef struct network {        /* Information on a network. */
  93         u8_t            n;              /* Network number. */
  94         ether_addr_t    eth;            /* Ethernet address of this net. */
  95         u8_t            type;           /* What kind of net is this? */
  96         i8_t            sol_ct;         /* Router solicitation count. */
  97         ether_addr_t    conflict;       /* Address conflict with this one. */
  98         unsigned        flags;          /* Various flags. */
  99         fd_t            *fdp;           /* Current open device. */
 100         struct network  *wait;          /* Wait for a resource list. */
 101         ipaddr_t        ip;             /* IP address of this net. */
 102         ipaddr_t        mask;           /* Associated netmask. */
 103         ipaddr_t        gateway;        /* My router. */
 104         ipaddr_t        server;         /* My DHCP server. */
 105         const char      *hostname;      /* Optional hostname to query for. */
 106         time_t          start;          /* Query or lease start time. */
 107         time_t          delta;          /* Query again after delta seconds. */
 108         time_t          renew;          /* Next query or go into renewal. */
 109         time_t          rebind;         /* When to go into rebind. */
 110         time_t          lease;          /* When our lease expires. */
 111         time_t          solicit;        /* Time to do a router solicitation. */
 112 } network_t;
 113
 114 /* Flags. */
 115 #define NF_NEGOTIATING  0x001           /* Negotiating with a DHCP server. */
 116 #define NF_BOUND        0x002           /* Address configured through DHCP. */
 117 #define NF_SERVING      0x004           /* I'm a server on this network. */
 118 #define NF_RELAYING     0x008           /* I'm relaying for this network. */
 119 #define NF_WAIT         0x010           /* Wait for a resource to free up. */
 120 #define NF_IRDP         0x020           /* IRDP is used on this net. */
 121 #define NF_CONFLICT     0x040           /* There is an address conflict. */
 122 #define NF_POSSESSIVE   0x080           /* Keep address if lease expires. */
 123 #define NF_INFORM       0x100           /* It's ok to answer DHCPINFORM. */
 124
 125 /* Functions defined in dhcpd.c. */
 126 void report(const char *label);
 127 void fatal(const char *label);
 128 void *allocate(size_t size);
 129 int ifname2if(const char *name);
 130 network_t *if2net(int n);
 131
 132 /* Devices.c */
 133 void get_buf(buf_t **bp);
 134 void put_buf(buf_t **bp);
 135 void give_buf(buf_t **dbp, buf_t **sbp);
 136 network_t *newnetwork(void);
 137 void closefd(fd_t *fdp);
 138 int opendev(network_t *np, fdtype_t fdtype, int compete);
 139 void closedev(network_t *np, fdtype_t fdtype);
 140 char *ipdev(int n);
 141 void set_ipconf(char *device, ipaddr_t ip, ipaddr_t mask, unsigned mtu);
 142
 143 /* Ether.c */
 144 void udp2ether(buf_t *bp, network_t *np);
 145 int ether2udp(buf_t *bp);
 146 void make_arp(buf_t *bp, network_t *np);
 147 int is_arp_me(buf_t *bp, network_t *np);
 148 void icmp_solicit(buf_t *bp);
 149 void icmp_advert(buf_t *bp, network_t *np);
 150 ipaddr_t icmp_is_advert(buf_t *bp);
 151
 152 /* Tags.c */
 153 #define gettag(dp, st, pd, pl)  dhcp_gettag((dp), (st), (pd), (pl))
 154 void settag(dhcp_t *dp, int tag, void *data, size_t len);
 155 char *cidr_ntoa(ipaddr_t addr, ipaddr_t mask);
 156 void ether2clid(u8_t *clid, ether_addr_t *eth);
 157 void initdhcpconf(void);
 158 int makedhcp(dhcp_t *dp, u8_t *class, size_t calen, u8_t *client, size_t cilen,
 159                                 ipaddr_t ip, ipaddr_t ifip, network_t *np);
 160 char *dhcptypename(int type);
 161 void printdhcp(dhcp_t *dp);