sys/src/cmd/ns.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <bio.h>
   4 #include <auth.h>
   5 #include <fcall.h>
   6
   7 #pragma varargck        type    "P"     char*
   8
   9 int     nsrv;
  10 Dir     *srv;
  11 Biobuf  stdout;
  12
  13 typedef struct Mount Mount;
  14
  15 struct Mount
  16 {
  17         char    *cmd;
  18         char    *flag;
  19         char    *new;
  20         char    *old;
  21         char    *spec;
  22 };
  23
  24 void    xlatemnt(Mount*);
  25 char    *quote(char*);
  26
  27 int     rflag;
  28
  29 void
  30 usage(void)
  31 {
  32         fprint(2, "usage: ns [-r] [pid]\n");
  33         exits("usage");
  34 }
  35
  36 void
  37 main(int argc, char **argv)
  38 {
  39         Mount *m;
  40         int line, fd, n, pid;
  41         char buf[1024], *av[5];
  42
  43         ARGBEGIN{
  44         case 'r':
  45                 rflag++;
  46                 break;
  47         default:
  48                 usage();
  49         }ARGEND
  50
  51         if(argc > 1)
  52                 usage();
  53         if(argc == 1){
  54                 pid = atoi(argv[0]);
  55                 if(pid == 0)
  56                         usage();
  57         }else
  58                 pid = getpid();
  59
  60         Binit(&stdout, 1, OWRITE);
  61
  62         sprint(buf, "/proc/%d/ns", pid);
  63         fd = open(buf, OREAD);
  64         if(fd < 0) {
  65                 fprint(2, "ns: open %s: %r\n", buf);
  66                 exits("open ns");
  67         }
  68
  69         for(line=1; ; line++) {
  70                 n = read(fd, buf, sizeof(buf));
  71                 if(n == sizeof(buf)) {
  72                         fprint(2, "ns: ns string too long\n");
  73                         exits("read ns");
  74                 }
  75                 if(n < 0) {
  76                         fprint(2, "ns: read %r\n");
  77                         exits("read ns");
  78                 }
  79                 if(n == 0)
  80                         break;
  81                 buf[n] = '\0';
  82
  83                 m = mallocz(sizeof(Mount), 1);
  84                 if(m == nil) {
  85                         fprint(2, "ns: no memory: %r\n");
  86                         exits("no memory");
  87                 }
  88
  89                 n = tokenize(buf, av, 5);
  90                 switch(n){
  91                 case 2:
  92                         if(strcmp(av[0], "cd") == 0){
  93                                 Bprint(&stdout, "%s %s\n", av[0], av[1]);
  94                                 continue;
  95                         }
  96                         /* fall through */
  97                 default:
  98                         fprint(2, "ns: unrecognized format of ns file: %d elements on line %d\n", n, line);
  99                         exits("format");
 100                 case 5:
 101                         m->cmd = strdup(av[0]);
 102                         m->flag = strdup(av[1]);
 103                         m->new = strdup(av[2]);
 104                         m->old = strdup(av[3]);
 105                         m->spec = strdup(av[4]);
 106                         break;
 107                 case 4:
 108                         if(av[1][0] == '-'){
 109                                 m->cmd = strdup(av[0]);
 110                                 m->flag = strdup(av[1]);
 111                                 m->new = strdup(av[2]);
 112                                 m->old = strdup(av[3]);
 113                                 m->spec = strdup("");
 114                         }else{
 115                                 m->cmd = strdup(av[0]);
 116                                 m->flag = strdup("");
 117                                 m->new = strdup(av[1]);
 118                                 m->old = strdup(av[2]);
 119                                 m->spec = strdup(av[3]);
 120                         }
 121                         break;
 122                 case 3:
 123                         m->cmd = strdup(av[0]);
 124                         m->flag = strdup("");
 125                         m->new = strdup(av[1]);
 126                         m->old = strdup(av[2]);
 127                         m->spec = strdup("");
 128                         break;
 129                 }
 130
 131                 if(!rflag && strcmp(m->cmd, "mount")==0)
 132                         xlatemnt(m);
 133
 134                 Bprint(&stdout, "%s %s %s %s %s\n", m->cmd, m->flag,
 135                         quote(m->new), quote(m->old), quote(m->spec));
 136
 137                 free(m->cmd);
 138                 free(m->flag);
 139                 free(m->new);
 140                 free(m->old);
 141                 free(m->spec);
 142                 free(m);
 143         }
 144
 145         exits(nil);
 146 }
 147
 148 void
 149 xlatemnt(Mount *m)
 150 {
 151         int n, fd;
 152         char *s, *t, *net, *port;
 153         char buf[256];
 154
 155         if(strncmp(m->new, "/net/", 5) != 0)
 156                 return;
 157
 158         s = strdup(m->new);
 159         net = s+5;
 160         for(t=net; *t!='/'; t++)
 161                 if(*t == '\0')
 162                         goto Return;
 163         *t = '\0';
 164         port = t+1;
 165         for(t=port; *t!='/'; t++)
 166                 if(*t == '\0')
 167                         goto Return;
 168         *t = '\0';
 169         if(strcmp(t+1, "data") != 0)
 170                 goto Return;
 171         snprint(buf, sizeof buf, "/net/%s/%s/remote", net, port);
 172         fd = open(buf, OREAD);
 173         if(fd < 0)
 174                 goto Return;
 175         n = read(fd, buf, sizeof buf);
 176         close(fd);
 177         if(n<=1 || n>sizeof buf)
 178                 goto Return;
 179         if(buf[n-1] == '\n')
 180                 --n;
 181         buf[n] = '\0';
 182         t = malloc(strlen(net)+1+n+1);
 183         if(t == nil)
 184                 goto Return;
 185         sprint(t, "%s!%s", net, buf);
 186         free(m->new);
 187         m->new = t;
 188
 189 Return:
 190         free(s);
 191 }
 192
 193 char*
 194 quote(char *s)
 195 {
 196         static char buf[3][1024];
 197         static int i;
 198         char *p, *ep;
 199
 200         if(strpbrk(s, " '\\\t#$") == nil)
 201                 return s;
 202         i = (i+1)%3;
 203         p = &buf[i][0];
 204         ep = &buf[i][1024];
 205         *p++ = '\'';
 206         while(p < ep-5){
 207                 switch(*s){
 208                 case '\0':
 209                         goto out;
 210                 case '\'':
 211                         *p++ = '\'';
 212                         break;
 213                 }
 214                 *p++ = *s++;
 215         }
 216     out:
 217         *p++ = '\'';
 218         *p = '\0';
 219         return buf[i];
 220 }