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