1 /* 2 * @(#) tcpd.h 1.5 96/03/19 16:22:24 3 * 4 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 5 */ 6 7 /* Structure to describe one communications endpoint. */ 8 9 #define STRING_LENGTH 128 /* hosts, users, processes */ 10 11 struct host_info { 12 char name[STRING_LENGTH]; /* access via eval_hostname(host) */ 13 char addr[STRING_LENGTH]; /* access via eval_hostaddr(host) */ 14 struct sockaddr_in *sin; /* socket address or 0 */ 15 struct t_unitdata *unit; /* TLI transport address or 0 */ 16 struct request_info *request; /* for shared information */ 17 }; 18 19 /* Structure to describe what we know about a service request. */ 20 21 struct request_info { 22 int fd; /* socket handle */ 23 char user[STRING_LENGTH]; /* access via eval_user(request) */ 24 char daemon[STRING_LENGTH]; /* access via eval_daemon(request) */ 25 char pid[10]; /* access via eval_pid(request) */ 26 struct host_info client[1]; /* client endpoint info */ 27 struct host_info server[1]; /* server endpoint info */ 28 void (*sink) /* datagram sink function or 0 */ 29 __P((int)); 30 void (*hostname) /* address to printable hostname */ 31 __P((struct host_info *)); 32 void (*hostaddr) /* address to printable address */ 33 __P((struct host_info *)); 34 void (*cleanup) /* cleanup function or 0 */ 35 __P((void)); 36 struct netconfig *config; /* netdir handle */ 37 }; 38 39 /* Common string operations. Less clutter should be more readable. */ 40 41 #define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; } 42 43 #define STRN_EQ(x,y,l) (strncasecmp((x),(y),(l)) == 0) 44 #define STRN_NE(x,y,l) (strncasecmp((x),(y),(l)) != 0) 45 #define STR_EQ(x,y) (strcasecmp((x),(y)) == 0) 46 #define STR_NE(x,y) (strcasecmp((x),(y)) != 0) 47 48 /* 49 * Initially, all above strings have the empty value. Information that 50 * cannot be determined at runtime is set to "unknown", so that we can 51 * distinguish between `unavailable' and `not yet looked up'. A hostname 52 * that we do not believe in is set to "paranoid". 53 */ 54 55 #define STRING_UNKNOWN "unknown" /* lookup failed */ 56 #define STRING_PARANOID "paranoid" /* hostname conflict */ 57 58 extern char unknown[]; 59 extern char paranoid[]; 60 61 #define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid)) 62 63 #define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0) 64 65 /* Global functions. */ 66 67 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT) 68 extern void fromhost /* get/validate client host info */ 69 __P((struct request_info *)); 70 #else 71 #define fromhost sock_host /* no TLI support needed */ 72 #endif 73 74 extern int hosts_access /* access control */ 75 __P((struct request_info *)); 76 extern int hosts_ctl /* limited interface to hosts_access */ 77 __P((char *, char *, char *, char *)); 78 extern void shell_cmd /* execute shell command */ 79 __P((char *)); 80 extern char *percent_x /* do %<char> expansion */ 81 __P((char *, int, char *, struct request_info *)); 82 extern void rfc931 /* client name from RFC 931 daemon */ 83 __P((struct sockaddr_in *, struct sockaddr_in *, char *)); 84 extern void clean_exit /* clean up and exit */ 85 __P((struct request_info *)); 86 extern void refuse /* clean up and exit */ 87 __P((struct request_info *)); 88 extern char *xgets /* fgets() on steroids */ 89 __P((char *, int, FILE *)); 90 extern char *split_at /* strchr() and split */ 91 __P((char *, int)); 92 extern unsigned long dot_quad_addr /* restricted inet_addr() */ 93 __P((char *)); 94 95 /* Global variables. */ 96 97 extern int allow_severity; /* for connection logging */ 98 extern int deny_severity; /* for connection logging */ 99 extern char *hosts_allow_table; /* for verification mode redirection */ 100 extern char *hosts_deny_table; /* for verification mode redirection */ 101 extern int hosts_access_verbose; /* for verbose matching mode */ 102 extern int rfc931_timeout; /* user lookup timeout */ 103 extern int resident; /* > 0 if resident process */ 104 105 /* 106 * Routines for controlled initialization and update of request structure 107 * attributes. Each attribute has its own key. 108 */ 109 110 extern struct request_info *request_init /* initialize request */ 111 __P((struct request_info *,...)); 112 extern struct request_info *request_set /* update request structure */ 113 __P((struct request_info *,...)); 114 115 #define RQ_FILE 1 /* file descriptor */ 116 #define RQ_DAEMON 2 /* server process (argv[0]) */ 117 #define RQ_USER 3 /* client user name */ 118 #define RQ_CLIENT_NAME 4 /* client host name */ 119 #define RQ_CLIENT_ADDR 5 /* client host address */ 120 #define RQ_CLIENT_SIN 6 /* client endpoint (internal) */ 121 #define RQ_SERVER_NAME 7 /* server host name */ 122 #define RQ_SERVER_ADDR 8 /* server host address */ 123 #define RQ_SERVER_SIN 9 /* server endpoint (internal) */ 124 125 /* 126 * Routines for delayed evaluation of request attributes. Each attribute 127 * type has its own access method. The trivial ones are implemented by 128 * macros. The other ones are wrappers around the transport-specific host 129 * name, address, and client user lookup methods. The request_info and 130 * host_info structures serve as caches for the lookup results. 131 */ 132 133 extern char *eval_user /* client user */ 134 __P((struct request_info *)); 135 extern char *eval_hostname /* printable hostname */ 136 __P((struct host_info *)); 137 extern char *eval_hostaddr /* printable host address */ 138 __P((struct host_info *)); 139 extern char *eval_hostinfo /* host name or address */ 140 __P((struct host_info *)); 141 extern char *eval_client /* whatever is available */ 142 __P((struct request_info *)); 143 extern char *eval_server /* whatever is available */ 144 __P((struct request_info *)); 145 #define eval_daemon(r) ((r)->daemon) /* daemon process name */ 146 #define eval_pid(r) ((r)->pid) /* process id */ 147 148 /* Socket-specific methods, including DNS hostname lookups. */ 149 150 extern void sock_host /* look up endpoint addresses */ 151 __P((struct request_info *)); 152 extern void sock_hostname /* translate address to hostname */ 153 __P((struct host_info *)); 154 extern void sock_hostaddr /* address to printable address */ 155 __P((struct host_info *)); 156 #define sock_methods(r) \ 157 { (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; } 158 159 /* The System V Transport-Level Interface (TLI) interface. */ 160 161 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT) 162 extern void tli_host /* look up endpoint addresses etc. */ 163 __P((struct request_info *)); 164 #endif 165 166 /* 167 * Problem reporting interface. Additional file/line context is reported 168 * when available. The jump buffer (tcpd_buf) is not declared here, or 169 * everyone would have to include <setjmp.h>. 170 */ 171 172 extern void tcpd_warn /* report problem and proceed */ 173 __P((char *, ...)); 174 extern void tcpd_jump /* report problem and jump */ 175 __P((char *, ...)); 176 177 struct tcpd_context { 178 char *file; /* current file */ 179 int line; /* current line */ 180 }; 181 extern struct tcpd_context tcpd_context; 182 183 /* 184 * While processing access control rules, error conditions are handled by 185 * jumping back into the hosts_access() routine. This is cleaner than 186 * checking the return value of each and every silly little function. The 187 * (-1) returns are here because zero is already taken by longjmp(). 188 */ 189 190 #define AC_PERMIT 1 /* permit access */ 191 #define AC_DENY (-1) /* deny_access */ 192 #define AC_ERROR AC_DENY /* XXX */ 193 194 /* 195 * In verification mode an option function should just say what it would do, 196 * instead of really doing it. An option function that would not return 197 * should clear the dry_run flag to inform the caller of this unusual 198 * behavior. 199 */ 200 201 extern void process_options /* execute options */ 202 __P((char *, struct request_info *)); 203 extern int dry_run; /* verification flag */ 204 extern void fix_options /* get rid of IP-level socket options */ 205 __P((struct request_info *)); 206 /* Bug workarounds. */ 207 208 #ifdef INET_ADDR_BUG /* inet_addr() returns struct */ 209 #define inet_addr fix_inet_addr 210 extern long fix_inet_addr __P((char *)); 211 #endif 212 213 #ifdef BROKEN_FGETS /* partial reads from sockets */ 214 #define fgets fix_fgets 215 extern char *fix_fgets __P((char *, int, FILE *)); 216 #endif 217 218 #ifdef RECVFROM_BUG /* no address family info */ 219 #define recvfrom fix_recvfrom 220 extern int fix_recvfrom __P((int, char *, int, int, struct sockaddr *, int *)); 221 #endif 222 223 #ifdef GETPEERNAME_BUG /* claims success with UDP */ 224 #define getpeername fix_getpeername 225 extern int fix_getpeername __P((int, struct sockaddr *, int *)); 226 #endif 227 228 #ifdef SOLARIS_24_GETHOSTBYNAME_BUG /* lists addresses as aliases */ 229 #define gethostbyname fix_gethostbyname 230 extern struct hostent *fix_gethostbyname __P((char *)); 231 #endif 232 233 #ifdef USE_STRSEP /* libc calls strtok() */ 234 #define strtok fix_strtok 235 extern char *fix_strtok __P((char *, char *)); 236 #endif 237 238 #ifdef LIBC_CALLS_STRTOK /* libc calls strtok() */ 239 #define strtok my_strtok 240 extern char *my_strtok __P((char *, char *)); 241 #endif 242