sys/src/libc/9sys/dial.c

   1 #include <u.h>
   2 #include <libc.h>
   3
   4 typedef struct DS DS;
   5
   6 static int      call(char*, char*, DS*);
   7 static int      csdial(DS*);
   8 static void     _dial_string_parse(char*, DS*);
   9
  10 enum
  11 {
  12         Maxstring       = 128,
  13         Maxpath         = 256,
  14 };
  15
  16 struct DS {
  17         /* dist string */
  18         char    buf[Maxstring];
  19         char    *netdir;
  20         char    *proto;
  21         char    *rem;
  22
  23         /* other args */
  24         char    *local;
  25         char    *dir;
  26         int     *cfdp;
  27 };
  28
  29
  30 /*
  31  *  the dialstring is of the form '[/net/]proto!dest'
  32  */
  33 int
  34 dial(char *dest, char *local, char *dir, int *cfdp)
  35 {
  36         DS ds;
  37         int rv;
  38         char err[ERRMAX], alterr[ERRMAX];
  39
  40         ds.local = local;
  41         ds.dir = dir;
  42         ds.cfdp = cfdp;
  43
  44         _dial_string_parse(dest, &ds);
  45         if(ds.netdir)
  46                 return csdial(&ds);
  47
  48         ds.netdir = "/net";
  49         rv = csdial(&ds);
  50         if(rv >= 0)
  51                 return rv;
  52         err[0] = '\0';
  53         errstr(err, sizeof err);
  54         if(strstr(err, "refused") != 0){
  55                 werrstr("%s", err);
  56                 return rv;
  57         }
  58         ds.netdir = "/net.alt";
  59         rv = csdial(&ds);
  60         if(rv >= 0)
  61                 return rv;
  62
  63         alterr[0] = 0;
  64         errstr(alterr, sizeof alterr);
  65         if(strstr(alterr, "translate") || strstr(alterr, "does not exist"))
  66                 werrstr("%s", err);
  67         else
  68                 werrstr("%s", alterr);
  69         return rv;
  70 }
  71
  72 static int
  73 csdial(DS *ds)
  74 {
  75         int n, fd, rv;
  76         char *p, buf[Maxstring], clone[Maxpath], err[ERRMAX], besterr[ERRMAX];
  77
  78         /*
  79          *  open connection server
  80          */
  81         snprint(buf, sizeof(buf), "%s/cs", ds->netdir);
  82         fd = open(buf, ORDWR);
  83         if(fd < 0){
  84                 /* no connection server, don't translate */
  85                 snprint(clone, sizeof(clone), "%s/%s/clone", ds->netdir, ds->proto);
  86                 return call(clone, ds->rem, ds);
  87         }
  88
  89         /*
  90          *  ask connection server to translate
  91          */
  92         snprint(buf, sizeof(buf), "%s!%s", ds->proto, ds->rem);
  93         if(write(fd, buf, strlen(buf)) < 0){
  94                 close(fd);
  95                 return -1;
  96         }
  97
  98         /*
  99          *  loop through each address from the connection server till
 100          *  we get one that works.
 101          */
 102         *besterr = 0;
 103         rv = -1;
 104         seek(fd, 0, 0);
 105         while((n = read(fd, buf, sizeof(buf) - 1)) > 0){
 106                 buf[n] = 0;
 107                 p = strchr(buf, ' ');
 108                 if(p == 0)
 109                         continue;
 110                 *p++ = 0;
 111                 rv = call(buf, p, ds);
 112                 if(rv >= 0)
 113                         break;
 114                 err[0] = '\0';
 115                 errstr(err, sizeof err);
 116                 if(strstr(err, "does not exist") == 0)
 117                         strcpy(besterr, err);
 118         }
 119         close(fd);
 120
 121         if(rv < 0 && *besterr)
 122                 werrstr("%s", besterr);
 123         else
 124                 werrstr("%s", err);
 125         return rv;
 126 }
 127
 128 static int
 129 call(char *clone, char *dest, DS *ds)
 130 {
 131         int fd, cfd, n;
 132         char cname[Maxpath], name[Maxpath], data[Maxpath], *p;
 133
 134         /* because cs is in a different name space, replace the mount point */
 135         if(*clone == '/' || *clone == '#'){
 136                 p = strchr(clone+1, '/');
 137                 if(p == nil)
 138                         p = clone;
 139                 else
 140                         p++;
 141         } else
 142                 p = clone;
 143         snprint(cname, sizeof cname, "%s/%s", ds->netdir, p);
 144
 145         cfd = open(cname, ORDWR);
 146         if(cfd < 0)
 147                 return -1;
 148
 149         /* get directory name */
 150         n = read(cfd, name, sizeof(name)-1);
 151         if(n < 0){
 152                 close(cfd);
 153                 return -1;
 154         }
 155         name[n] = 0;
 156         for(p = name; *p == ' '; p++)
 157                 ;
 158         snprint(name, sizeof(name), "%ld", strtoul(p, 0, 0));
 159         p = strrchr(cname, '/');
 160         *p = 0;
 161         if(ds->dir)
 162                 snprint(ds->dir, NETPATHLEN, "%s/%s", cname, name);
 163         snprint(data, sizeof(data), "%s/%s/data", cname, name);
 164
 165         /* connect */
 166         if(ds->local)
 167                 snprint(name, sizeof(name), "connect %s %s", dest, ds->local);
 168         else
 169                 snprint(name, sizeof(name), "connect %s", dest);
 170         if(write(cfd, name, strlen(name)) < 0){
 171                 close(cfd);
 172                 return -1;
 173         }
 174
 175         /* open data connection */
 176         fd = open(data, ORDWR);
 177         if(fd < 0){
 178                 close(cfd);
 179                 return -1;
 180         }
 181         if(ds->cfdp)
 182                 *ds->cfdp = cfd;
 183         else
 184                 close(cfd);
 185         return fd;
 186 }
 187
 188 /*
 189  *  parse a dial string
 190  */
 191 static void
 192 _dial_string_parse(char *str, DS *ds)
 193 {
 194         char *p, *p2;
 195
 196         strncpy(ds->buf, str, Maxstring);
 197         ds->buf[Maxstring-1] = 0;
 198
 199         p = strchr(ds->buf, '!');
 200         if(p == 0) {
 201                 ds->netdir = 0;
 202                 ds->proto = "net";
 203                 ds->rem = ds->buf;
 204         } else {
 205                 p2 = ds->buf;
 206                 if(*p2 == '#'){
 207                         p2 = strchr(p2, '/');
 208                         if(p2 == nil || p2 > p)
 209                                 p2 = ds->buf;
 210                 }
 211                 if(*p2 != '/'){
 212                         ds->netdir = 0;
 213                         ds->proto = ds->buf;
 214                 } else {
 215                         for(p2 = p; *p2 != '/'; p2--)
 216                                 ;
 217                         *p2++ = 0;
 218                         ds->netdir = ds->buf;
 219                         ds->proto = p2;
 220                 }
 221                 *p = 0;
 222                 ds->rem = p + 1;
 223         }
 224 }