mdw@git.distorted.org.uk Git - adns/blob - src/setup.c

   1 /**/
   2
   3 #include <stdlib.h>
   4 #include <errno.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7 #include <fcntl.h>
   8
   9 #include <netdb.h>
  10 #include <arpa/inet.h>
  11
  12 #include "internal.h"
  13
  14 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
  15                  int serv, const char *fmt, va_list al) {
  16   if (!(ads->iflags & adns_if_debug) && (!prevent || (ads->iflags & prevent))) return;
  17   if (serv>=0) {
  18     fprintf(stderr,"adns%s: nameserver %s: ",pfx,inet_ntoa(ads->servers[serv].addr));
  19   } else {
  20     fprintf(stderr,"adns%s: ",pfx);
  21   }
  22   vfprintf(stderr,fmt,al);
  23   fputc('\n',stderr);
  24 }
  25
  26 void adns__debug(adns_state ads, int serv, const char *fmt, ...) {
  27   va_list al;
  28
  29   va_start(al,fmt);
  30   adns__vdiag(ads," debug",0,serv,fmt,al);
  31   va_end(al);
  32 }
  33
  34 void adns__warn(adns_state ads, int serv, const char *fmt, ...) {
  35   va_list al;
  36
  37   va_start(al,fmt);
  38   adns__vdiag(ads," warning",adns_if_noerrprint|adns_if_noserverwarn,serv,fmt,al);
  39   va_end(al);
  40 }
  41
  42 void adns__diag(adns_state ads, int serv, const char *fmt, ...) {
  43   va_list al;
  44
  45   va_start(al,fmt);
  46   adns__vdiag(ads,"",adns_if_noerrprint,serv,fmt,al);
  47   va_end(al);
  48 }
  49
  50
  51 void adns__vbuf_init(vbuf *vb) {
  52   vb->used= vb->avail= 0; vb->buf= 0;
  53 }
  54
  55 int adns__vbuf_ensure(vbuf *vb, int want) {
  56   void *nb;
  57
  58   if (vb->avail >= want) return 1;
  59   nb= realloc(vb->buf,want); if (!nb) return 0;
  60   vb->buf= nb;
  61   vb->avail= want;
  62   return 1;
  63 }
  64
  65 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len) {
  66   memcpy(vb->buf+vb->used,data,len);
  67   vb->used+= len;
  68 }
  69
  70 int adns__vbuf_append(vbuf *vb, const byte *data, int len) {
  71   int newlen;
  72   void *nb;
  73
  74   newlen= vb->used+len;
  75   if (vb->avail < newlen) {
  76     newlen <<= 1;
  77     nb= realloc(vb->buf,newlen);
  78     if (!nb) { newlen >>= 1; nb= realloc(vb->buf,newlen); }
  79     if (!nb) return 0;
  80     vb->buf= nb;
  81     vb->avail= newlen;
  82   }
  83   adns__vbuf_appendq(vb,data,len);
  84   return 1;
  85 }
  86
  87
  88 static void addserver(adns_state ads, struct in_addr addr) {
  89   int i;
  90   struct server *ss;
  91
  92   for (i=0; i<ads->nservers; i++) {
  93     if (ads->servers[i].addr.s_addr == addr.s_addr) {
  94       adns__debug(ads,-1,"duplicate nameserver %s ignored",inet_ntoa(addr));
  95       return;
  96     }
  97   }
  98
  99   if (ads->nservers>=MAXSERVERS) {
 100     adns__diag(ads,-1,"too many nameservers, ignoring %s",inet_ntoa(addr));
 101     return;
 102   }
 103
 104   ss= ads->servers+ads->nservers;
 105   ss->addr= addr;
 106   ads->nservers++;
 107 }
 108
 109 static void configparseerr(adns_state ads, const char *fn, int lno,
 110                            const char *fmt, ...) {
 111   va_list al;
 112
 113   if (ads->iflags & adns_if_noerrprint) return;
 114   if (lno==-1) fprintf(stderr,"adns: %s: ",fn);
 115   else fprintf(stderr,"adns: %s:%d: ",fn,lno);
 116   va_start(al,fmt);
 117   vfprintf(stderr,fmt,al);
 118   va_end(al);
 119   fputc('\n',stderr);
 120 }
 121
 122 static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
 123   struct in_addr ia;
 124
 125   if (!inet_aton(buf,&ia)) {
 126     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
 127     return;
 128   }
 129   adns__debug(ads,-1,"using nameserver %s",inet_ntoa(ia));
 130   addserver(ads,ia);
 131 }
 132
 133 static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
 134   if (!buf) return;
 135   adns__diag(ads,-1,"warning - `search' ignored FIXME");
 136 }
 137
 138 static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
 139   adns__diag(ads,-1,"warning - `sortlist' ignored FIXME");
 140 }
 141
 142 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
 143   if (!buf) return;
 144   adns__diag(ads,-1,"warning - `options' ignored FIXME");
 145 }
 146
 147 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
 148   ads->nservers= 0;
 149 }
 150
 151 static const struct configcommandinfo {
 152   const char *name;
 153   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 154 } configcommandinfos[]= {
 155   { "nameserver",        ccf_nameserver  },
 156   { "domain",            ccf_search      },
 157   { "search",            ccf_search      },
 158   { "sortlist",          ccf_sortlist    },
 159   { "options",           ccf_options     },
 160   { "clearnameservers",  ccf_clearnss    },
 161   {  0                                   }
 162 };
 163
 164 static void readconfig(adns_state ads, const char *filename) {
 165   char linebuf[2000], *p, *q;
 166   FILE *file;
 167   int lno, l, c;
 168   const struct configcommandinfo *ccip;
 169
 170   file= fopen(filename,"r");
 171   if (!file) {
 172     if (errno == ENOENT) {
 173       adns__debug(ads,-1,"configuration file `%s' does not exist",filename);
 174       return;
 175     }
 176     adns__diag(ads,-1,"cannot open configuration file `%s': %s",
 177                filename,strerror(errno));
 178     return;
 179   }
 180
 181   for (lno=1; fgets(linebuf,sizeof(linebuf),file); lno++) {
 182     l= strlen(linebuf);
 183     if (!l) continue;
 184     if (linebuf[l-1] != '\n' && !feof(file)) {
 185       adns__diag(ads,-1,"%s:%d: line too long",filename,lno);
 186       while ((c= getc(file)) != EOF && c != '\n') { }
 187       if (c == EOF) break;
 188       continue;
 189     }
 190     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 191     linebuf[l]= 0;
 192     p= linebuf;
 193     while (ctype_whitespace(*p)) p++;
 194     if (*p == '#' || *p == '\n') continue;
 195     q= p;
 196     while (*q && !ctype_whitespace(*q)) q++;
 197     for (ccip=configcommandinfos;
 198          ccip->name && strncmp(ccip->name,p,q-p);
 199          ccip++);
 200     if (!ccip->name) {
 201       adns__diag(ads,-1,"%s:%d: unknown configuration directive `%.*s'",
 202                  filename,lno,q-p,p);
 203       continue;
 204     }
 205     while (ctype_whitespace(*q)) q++;
 206     ccip->fn(ads,filename,lno,q);
 207   }
 208   if (ferror(file)) {
 209     adns__diag(ads,-1,"%s:%d: read error: %s",filename,lno,strerror(errno));
 210   }
 211   fclose(file);
 212 }
 213
 214 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 215   const char *value;
 216
 217   value= getenv(envvar);
 218   if (!value) adns__debug(ads,-1,"environment variable %s not set",envvar);
 219   else adns__debug(ads,-1,"environment variable %s set to `%s'",envvar,value);
 220   return value;
 221 }
 222
 223 static void readconfigenv(adns_state ads, const char *envvar) {
 224   const char *filename;
 225
 226   if (ads->iflags & adns_if_noenv) {
 227     adns__debug(ads,-1,"not checking environment variable `%s'",envvar);
 228     return;
 229   }
 230   filename= instrum_getenv(ads,envvar);
 231   if (filename) readconfig(ads,filename);
 232 }
 233
 234
 235 int adns__setnonblock(adns_state ads, int fd) {
 236   int r;
 237
 238   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 239   r |= O_NONBLOCK;
 240   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 241   return 0;
 242 }
 243
 244 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 245   adns_state ads;
 246   const char *res_options, *adns_res_options;
 247   struct protoent *proto;
 248   int r;
 249
 250   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 251   ads->iflags= flags;
 252   ads->diagfile= diagfile ? diagfile : stderr;
 253   LIST_INIT(ads->timew);
 254   LIST_INIT(ads->childw);
 255   LIST_INIT(ads->output);
 256   ads->nextid= 0x311f;
 257   ads->udpsocket= ads->tcpsocket= -1;
 258   adns__vbuf_init(&ads->rqbuf);
 259   adns__vbuf_init(&ads->tcpsend);
 260   adns__vbuf_init(&ads->tcprecv);
 261   ads->nservers= ads->tcpserver= 0;
 262   ads->tcpstate= server_disconnected;
 263   timerclear(&ads->tcptimeout);
 264
 265   res_options= instrum_getenv(ads,"RES_OPTIONS");
 266   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 267   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 268   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 269
 270   readconfig(ads,"/etc/resolv.conf");
 271   readconfigenv(ads,"RES_CONF");
 272   readconfigenv(ads,"ADNS_RES_CONF");
 273
 274   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 275   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 276
 277   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 278   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 279
 280   if (!ads->nservers) {
 281     struct in_addr ia;
 282     if (ads->iflags & adns_if_debug)
 283       fprintf(stderr,"adns: no nameservers, using localhost\n");
 284     ia.s_addr= INADDR_LOOPBACK;
 285     addserver(ads,ia);
 286   }
 287
 288   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 289   ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
 290   if (ads->udpsocket<0) { r= errno; goto x_free; }
 291
 292   /*fixme: nonblock */
 293
 294   *ads_r= ads;
 295   return 0;
 296
 297  x_free:
 298   free(ads);
 299   return r;
 300 }
 301
 302 int adns_finish(adns_state ads) {
 303   abort(); /* FIXME */
 304 }