1: #ifndef lint
   2: static char sccsid[] = "@(#)db_update.c	4.3 (Berkeley) 5/30/86";
   3: #endif
   4: 
   5: /*
   6:  * Copyright (c) 1986 Regents of the University of California
   7:  *	All Rights Reserved
   8:  */
   9: 
  10: #include <sys/types.h>
  11: #include <sys/time.h>
  12: #include <stdio.h>
  13: #include <syslog.h>
  14: #include <arpa/nameser.h>
  15: #include "db.h"
  16: 
  17: struct timeval  tt;
  18: extern FILE *ddt;
  19: 
  20: /*
  21:  * Update data base. Flags control the action.
  22:  * Inverse query tables modified.
  23:  */
  24: db_update(name, odp, newdp, flags)
  25:     char name[];
  26:     struct databuf *odp, *newdp;
  27:     int flags;
  28: {
  29:     register struct namebuf *np;
  30:     register struct databuf *dp, *pdp;
  31:     struct hashbuf *htp = hashtab;
  32:     char *fname;
  33: 
  34: #ifdef DEBUG
  35:     extern int debug;
  36: 
  37:     if (debug >= 3)
  38:         fprintf(ddt,"db_update( %s )\n",name);
  39: #endif
  40:     np = nlookup(name, &htp, &fname, newdp != NULL);
  41:     if (np == NULL || fname != name)
  42:         return (NONAME);
  43:     if (odp != NULL) {
  44:         pdp = NULL;
  45:         for (dp = np->n_data; dp != NULL; pdp = dp, dp = dp->d_next) {
  46:             if (!match(dp, odp->d_class, odp->d_type))
  47:                 continue;
  48: #ifdef DEBUG
  49:             if (debug >= 5)
  50:                 fprintf(ddt,"f = %#x, size = %d, %d (%d)\n",
  51:                     flags, odp->d_size, dp->d_size,
  52:                     db_cmp(dp, odp));
  53: #endif
  54:             if ((flags & DB_NODATA) &&
  55:                 !db_cmp(dp, odp)) {
  56:                 /* refresh ttl if cache entry */
  57:                 if (dp->d_zone == 0) {
  58:                     if (dp->d_ttl < tt.tv_sec ) {
  59:                         dp->d_ttl = odp->d_ttl;
  60:                         return (OK);
  61:                     }
  62:                     if (dp->d_ttl < odp->d_ttl)
  63:                         dp->d_ttl = odp->d_ttl;
  64:                 }
  65:                 return (DATAEXISTS);
  66:             }
  67:             if ((flags & DB_MEXIST) && db_cmp(dp, odp))
  68:                 return (NODATA);
  69:             if (flags & DB_DELETE) {
  70:                 if (pdp == NULL)
  71:                     np->n_data = dp->d_next;
  72:                 else
  73:                     pdp->d_next = dp->d_next;
  74:                 rminv(dp);
  75:                 (void) free((char *)dp);
  76:             }
  77:         }
  78:     }
  79:     if (newdp == NULL)
  80:         return (OK);
  81:     addinv(np, newdp);  /* modify inverse query tables */
  82: 
  83:     /* Add to end of list, generally preserving order */
  84:     newdp->d_next = NULL;
  85:     if ((dp = np->n_data) == NULL)  {
  86:         np->n_data = newdp;
  87:         return (OK);
  88:     }
  89:     while (dp->d_next != NULL) {
  90:         dp = dp->d_next;
  91:         /* NEEDS: check for duplicate WKS records and flag error */
  92:     }
  93:     dp->d_next = newdp;
  94:     return (OK);
  95: }
  96: 
  97: struct invbuf *invtab[INVHASHSZ];   /* Inverse query hash table */
  98: 
  99: /*
 100:  * Add data 'dp' to inverse query tables for name 'np'.
 101:  */
 102: addinv(np, dp)
 103:     struct namebuf *np;
 104:     struct databuf *dp;
 105: {
 106:     register struct invbuf *ip;
 107:     register int hval, i;
 108: 
 109:     switch (dp->d_type) {
 110:     case T_A:
 111:     case T_UID:
 112:     case T_GID:
 113:         break;
 114: 
 115:     default:
 116:         return;
 117:     }
 118: 
 119:     hval = dhash(dp->d_data, dp->d_size);
 120:     for (ip = invtab[hval]; ip != NULL; ip = ip->i_next)
 121:         for (i = 0; i < INVBLKSZ; i++)
 122:             if (ip->i_dname[i] == NULL) {
 123:                 ip->i_dname[i] = np;
 124:                 return;
 125:             }
 126:     ip = saveinv();
 127:     ip->i_next = invtab[hval];
 128:     invtab[hval] = ip;
 129:     ip->i_dname[0] = np;
 130: }
 131: 
 132: /*
 133:  * Remove data 'odp' from inverse query table.
 134:  */
 135: rminv(odp)
 136:     struct databuf *odp;
 137: {
 138:     register struct invbuf *ip;
 139:     register struct databuf *dp;
 140:     struct namebuf *np;
 141:     register int i;
 142: 
 143:     for (ip = invtab[dhash(odp->d_data, odp->d_size)]; ip != NULL;
 144:         ip = ip->i_next) {
 145:         for (i = 0; i < INVBLKSZ; i++) {
 146:             if ((np = ip->i_dname[i]) == NULL)
 147:                 break;
 148:             for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
 149:                 if (!match(dp, odp->d_class, odp->d_type))
 150:                     continue;
 151:                 if (db_cmp(dp, odp))
 152:                     continue;
 153:                 while (i < INVBLKSZ-1) {
 154:                     ip->i_dname[i] = ip->i_dname[i+1];
 155:                     i++;
 156:                 }
 157:                 ip->i_dname[i] = NULL;
 158:                 return;
 159:             }
 160:         }
 161:     }
 162: }
 163: 
 164: /*
 165:  * Compute hash value from data.
 166:  */
 167: dhash(dp, dlen)
 168:     char *dp;
 169:     int dlen;
 170: {
 171:     register char *cp;
 172:     register unsigned hval;
 173:     register int n;
 174: 
 175:     n = dlen;
 176:     if (n > 8)
 177:         n = 8;
 178:     hval = 0;
 179:     for (cp = dp; --n >= 0; ) {
 180:         hval <<= 1;
 181:         hval += *cp++;
 182:     }
 183:     return (hval % INVHASHSZ);
 184: }
 185: 
 186: /*
 187:  * Compare data sections from databufs for equivalence.  Must be case
 188:  * insensitive for some domain names.  We assume that they are the
 189:  * same type when they are passed.  Return 0 if equivalent, nonzero
 190:  * otherwise.
 191:  */
 192: 
 193: db_cmp(dp1, dp2)
 194:     register struct databuf *dp1, *dp2;
 195: 
 196: {
 197:     register char *cp1, *cp2;
 198:     int len;
 199: 
 200:     if (dp1->d_size != dp2->d_size)
 201:         return(1);
 202:     switch (dp1->d_type) {
 203: 
 204:     case T_A:
 205:     case T_UID:
 206:     case T_GID:
 207:     case T_WKS:
 208:     case T_NULL:
 209:         return(bcmp(dp1->d_data, dp2->d_data, dp1->d_size));
 210: 
 211:     case T_NS:
 212:     case T_CNAME:
 213:     case T_PTR:
 214:     case T_MB:
 215:     case T_MG:
 216:     case T_MR:
 217:     case T_UINFO:
 218:         return(cistrcmp(dp1->d_data, dp2->d_data));
 219: 
 220:     case T_HINFO:
 221:         cp1 = dp1->d_data;
 222:         cp2 = dp2->d_data;
 223:         len = *cp1;
 224:         if (cistrncmp(++cp1, ++cp2, len))
 225:             return(1);
 226:         cp1 += len;
 227:         cp2 += len;
 228:         len = *cp1;
 229:         return(cistrncmp(++cp1, ++cp2, len));
 230: 
 231:     case T_SOA:
 232:     case T_MINFO:
 233:         if (cistrcmp(dp1->d_data, dp2->d_data))
 234:             return(1);
 235:         cp1 = dp1->d_data + strlen(dp1->d_data) + 1;
 236:         cp2 = dp2->d_data + strlen(dp2->d_data) + 1;
 237:         if (dp1->d_type != T_SOA)
 238:             return(cistrcmp(cp1, cp2));
 239:         if (cistrcmp(cp1, cp2))
 240:             return(1);
 241:         cp1 += strlen(cp1) + 1;
 242:         cp2 += strlen(cp2) + 1;
 243:         return(bcmp(cp1, cp2, sizeof(u_long) * 5));
 244: 
 245:     case T_MX:
 246:         cp1 = dp1->d_data;
 247:         cp2 = dp2->d_data;
 248:         if (*cp1++ != *cp2++ || *cp1++ != *cp2++)   /* cmp prio */
 249:             return(1);
 250:         return(cistrcmp(cp1, cp2));
 251: 
 252:     default:
 253:         return (1);
 254:     }
 255: }

Defined functions

addinv defined in line 102; used 1 times
  • in line 81
db_cmp defined in line 193; used 4 times
db_update defined in line 24; used 2 times
dhash defined in line 167; used 3 times
rminv defined in line 135; used 8 times

Defined variables

invtab defined in line 97; used 10 times
sccsid defined in line 2; never used
tt defined in line 17; used 1 times
  • in line 58
Last modified: 1986-05-30
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