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| 1 | +#include "u.h" |
| 2 | +#include "lib.h" |
| 3 | +#include "dat.h" |
| 4 | +#include "fns.h" |
| 5 | +#include "error.h" |
| 6 | + |
| 7 | +enum |
| 8 | +{ |
| 9 | + Maxenvsize = 16300, |
| 10 | +}; |
| 11 | + |
| 12 | +static Egrp *envgrp(Chan *c); |
| 13 | +static int envwriteable(Chan *c); |
| 14 | +static void initunix(); |
| 15 | + |
| 16 | +static Egrp unixegrp; /* unix environment group */ |
| 17 | + |
| 18 | +static Evalue* |
| 19 | +envlookup(Egrp *eg, char *name, ulong qidpath) |
| 20 | +{ |
| 21 | + Evalue *e; |
| 22 | + int i; |
| 23 | + |
| 24 | + for(i=0; i<eg->nent; i++){ |
| 25 | + e = eg->ent[i]; |
| 26 | + if(e->qid.path == qidpath || (name && e->name[0]==name[0] && strcmp(e->name, name) == 0)) |
| 27 | + return e; |
| 28 | + } |
| 29 | + return nil; |
| 30 | +} |
| 31 | + |
| 32 | +static int |
| 33 | +envgen(Chan *c, char *name, Dirtab *_1, int _2, int s, Dir *dp) |
| 34 | +{ |
| 35 | + Egrp *eg; |
| 36 | + Evalue *e; |
| 37 | + |
| 38 | + if(s == DEVDOTDOT){ |
| 39 | + devdir(c, c->qid, "#e", 0, eve, DMDIR|0775, dp); |
| 40 | + return 1; |
| 41 | + } |
| 42 | + |
| 43 | + eg = envgrp(c); |
| 44 | + rlock(&eg->lk); |
| 45 | + e = 0; |
| 46 | + if(name) |
| 47 | + e = envlookup(eg, name, -1); |
| 48 | + else if(s < eg->nent) |
| 49 | + e = eg->ent[s]; |
| 50 | + |
| 51 | + if(e == 0) { |
| 52 | + runlock(&eg->lk); |
| 53 | + return -1; |
| 54 | + } |
| 55 | + |
| 56 | + /* make sure name string continues to exist after we release lock */ |
| 57 | + kstrcpy(up->genbuf, e->name, sizeof up->genbuf); |
| 58 | + devdir(c, e->qid, up->genbuf, e->len, eve, 0666, dp); |
| 59 | + runlock(&eg->lk); |
| 60 | + return 1; |
| 61 | +} |
| 62 | + |
| 63 | +static Chan* |
| 64 | +envattach(char *spec) |
| 65 | +{ |
| 66 | + Chan *c; |
| 67 | + |
| 68 | + if(spec && *spec) { |
| 69 | + error(Ebadarg); |
| 70 | + } |
| 71 | + initunix(); |
| 72 | + c = devattach('e', spec); |
| 73 | + c->aux = &unixegrp; |
| 74 | + return c; |
| 75 | +} |
| 76 | + |
| 77 | +static Walkqid* |
| 78 | +envwalk(Chan *c, Chan *nc, char **name, int nname) |
| 79 | +{ |
| 80 | + return devwalk(c, nc, name, nname, 0, 0, envgen); |
| 81 | +} |
| 82 | + |
| 83 | +static int |
| 84 | +envstat(Chan *c, uchar *db, int n) |
| 85 | +{ |
| 86 | + if(c->qid.type & QTDIR) |
| 87 | + c->qid.vers = envgrp(c)->vers; |
| 88 | + return devstat(c, db, n, 0, 0, envgen); |
| 89 | +} |
| 90 | + |
| 91 | +static Chan* |
| 92 | +envopen(Chan *c, int omode) |
| 93 | +{ |
| 94 | + Egrp *eg; |
| 95 | + Evalue *e; |
| 96 | + int trunc; |
| 97 | + |
| 98 | + eg = envgrp(c); |
| 99 | + if(c->qid.type & QTDIR) { |
| 100 | + if(omode != OREAD) |
| 101 | + error(Eperm); |
| 102 | + } |
| 103 | + else { |
| 104 | + trunc = omode & OTRUNC; |
| 105 | + if(omode != OREAD && !envwriteable(c)) |
| 106 | + error(Eperm); |
| 107 | + if(trunc) |
| 108 | + wlock(&eg->lk); |
| 109 | + else |
| 110 | + rlock(&eg->lk); |
| 111 | + e = envlookup(eg, nil, c->qid.path); |
| 112 | + if(e == 0) { |
| 113 | + if(trunc) |
| 114 | + wunlock(&eg->lk); |
| 115 | + else |
| 116 | + runlock(&eg->lk); |
| 117 | + error(Enonexist); |
| 118 | + } |
| 119 | + if(trunc && e->value) { |
| 120 | + e->qid.vers++; |
| 121 | + free(e->value); |
| 122 | + e->value = 0; |
| 123 | + e->len = 0; |
| 124 | + } |
| 125 | + if(trunc) |
| 126 | + wunlock(&eg->lk); |
| 127 | + else |
| 128 | + runlock(&eg->lk); |
| 129 | + } |
| 130 | + c->mode = openmode(omode); |
| 131 | + c->flag |= COPEN; |
| 132 | + c->offset = 0; |
| 133 | + return c; |
| 134 | +} |
| 135 | + |
| 136 | +static Chan* |
| 137 | +envcreate(Chan *c, char *name, int omode, ulong _) |
| 138 | +{ |
| 139 | + Egrp *eg; |
| 140 | + Evalue *e; |
| 141 | + Evalue **ent; |
| 142 | + |
| 143 | + if(c->qid.type != QTDIR) |
| 144 | + error(Eperm); |
| 145 | + if(strlen(name) >= sizeof up->genbuf) |
| 146 | + error("name too long"); /* protect envgen */ |
| 147 | + |
| 148 | + omode = openmode(omode); |
| 149 | + eg = envgrp(c); |
| 150 | + |
| 151 | + wlock(&eg->lk); |
| 152 | + if(waserror()) { |
| 153 | + wunlock(&eg->lk); |
| 154 | + nexterror(); |
| 155 | + } |
| 156 | + |
| 157 | + if(envlookup(eg, name, -1)) |
| 158 | + error(Eexist); |
| 159 | + |
| 160 | + e = smalloc(sizeof(Evalue)); |
| 161 | + e->name = smalloc(strlen(name)+1); |
| 162 | + strcpy(e->name, name); |
| 163 | + |
| 164 | + if(eg->nent == eg->ment){ |
| 165 | + eg->ment += 32; |
| 166 | + ent = smalloc(sizeof(eg->ent[0])*eg->ment); |
| 167 | + if(eg->nent) |
| 168 | + memmove(ent, eg->ent, sizeof(eg->ent[0])*eg->nent); |
| 169 | + free(eg->ent); |
| 170 | + eg->ent = ent; |
| 171 | + } |
| 172 | + e->qid.path = ++eg->path; |
| 173 | + e->qid.vers = 0; |
| 174 | + eg->vers++; |
| 175 | + eg->ent[eg->nent++] = e; |
| 176 | + c->qid = e->qid; |
| 177 | + |
| 178 | + wunlock(&eg->lk); |
| 179 | + poperror(); |
| 180 | + |
| 181 | + c->offset = 0; |
| 182 | + c->mode = omode; |
| 183 | + c->flag |= COPEN; |
| 184 | + return c; |
| 185 | +} |
| 186 | + |
| 187 | +static void |
| 188 | +envremove(Chan *c) |
| 189 | +{ |
| 190 | + int i; |
| 191 | + Egrp *eg; |
| 192 | + Evalue *e; |
| 193 | + |
| 194 | + if(c->qid.type & QTDIR) |
| 195 | + error(Eperm); |
| 196 | + |
| 197 | + eg = envgrp(c); |
| 198 | + wlock(&eg->lk); |
| 199 | + e = 0; |
| 200 | + for(i=0; i<eg->nent; i++){ |
| 201 | + if(eg->ent[i]->qid.path == c->qid.path){ |
| 202 | + e = eg->ent[i]; |
| 203 | + eg->nent--; |
| 204 | + eg->ent[i] = eg->ent[eg->nent]; |
| 205 | + eg->vers++; |
| 206 | + break; |
| 207 | + } |
| 208 | + } |
| 209 | + wunlock(&eg->lk); |
| 210 | + if(e == 0) |
| 211 | + error(Enonexist); |
| 212 | + free(e->name); |
| 213 | + if(e->value) |
| 214 | + free(e->value); |
| 215 | + free(e); |
| 216 | +} |
| 217 | + |
| 218 | +static void |
| 219 | +envclose(Chan *c) |
| 220 | +{ |
| 221 | + /* |
| 222 | + * cclose can't fail, so errors from remove will be ignored. |
| 223 | + * since permissions aren't checked, |
| 224 | + * envremove can't not remove it if its there. |
| 225 | + */ |
| 226 | + if(c->flag & CRCLOSE) |
| 227 | + envremove(c); |
| 228 | +} |
| 229 | + |
| 230 | +static long |
| 231 | +envread(Chan *c, void *a, long n, vlong off) |
| 232 | +{ |
| 233 | + Egrp *eg; |
| 234 | + Evalue *e; |
| 235 | + ulong offset = off; |
| 236 | + |
| 237 | + if(c->qid.type & QTDIR) |
| 238 | + return devdirread(c, a, n, 0, 0, envgen); |
| 239 | + |
| 240 | + eg = envgrp(c); |
| 241 | + rlock(&eg->lk); |
| 242 | + e = envlookup(eg, nil, c->qid.path); |
| 243 | + if(e == 0) { |
| 244 | + runlock(&eg->lk); |
| 245 | + error(Enonexist); |
| 246 | + } |
| 247 | + |
| 248 | + if(offset > e->len) /* protects against overflow converting vlong to ulong */ |
| 249 | + n = 0; |
| 250 | + else if(offset + n > e->len) |
| 251 | + n = e->len - offset; |
| 252 | + if(n <= 0) |
| 253 | + n = 0; |
| 254 | + else |
| 255 | + memmove(a, e->value+offset, n); |
| 256 | + runlock(&eg->lk); |
| 257 | + return n; |
| 258 | +} |
| 259 | + |
| 260 | +static long |
| 261 | +envwrite(Chan *c, void *a, long n, vlong off) |
| 262 | +{ |
| 263 | + char *s; |
| 264 | + ulong len; |
| 265 | + Egrp *eg; |
| 266 | + Evalue *e; |
| 267 | + ulong offset = off; |
| 268 | + |
| 269 | + if(n <= 0) |
| 270 | + return 0; |
| 271 | + if(offset > Maxenvsize || n > (Maxenvsize - offset)) |
| 272 | + error(Etoobig); |
| 273 | + |
| 274 | + eg = envgrp(c); |
| 275 | + wlock(&eg->lk); |
| 276 | + e = envlookup(eg, nil, c->qid.path); |
| 277 | + if(e == 0) { |
| 278 | + wunlock(&eg->lk); |
| 279 | + error(Enonexist); |
| 280 | + } |
| 281 | + |
| 282 | + len = offset+n; |
| 283 | + if(len > e->len) { |
| 284 | + s = smalloc(len); |
| 285 | + if(e->value){ |
| 286 | + memmove(s, e->value, e->len); |
| 287 | + free(e->value); |
| 288 | + } |
| 289 | + e->value = s; |
| 290 | + e->len = len; |
| 291 | + } |
| 292 | + memmove(e->value+offset, a, n); |
| 293 | + e->qid.vers++; |
| 294 | + eg->vers++; |
| 295 | + wunlock(&eg->lk); |
| 296 | + return n; |
| 297 | +} |
| 298 | + |
| 299 | +Dev envdevtab = { |
| 300 | + 'e', |
| 301 | + "env", |
| 302 | + |
| 303 | + devreset, |
| 304 | + devinit, |
| 305 | + devshutdown, |
| 306 | + envattach, |
| 307 | + envwalk, |
| 308 | + envstat, |
| 309 | + envopen, |
| 310 | + envcreate, |
| 311 | + envclose, |
| 312 | + envread, |
| 313 | + devbread, |
| 314 | + envwrite, |
| 315 | + devbwrite, |
| 316 | + envremove, |
| 317 | + devwstat, |
| 318 | +}; |
| 319 | + |
| 320 | +extern char **environ; |
| 321 | + |
| 322 | +static void |
| 323 | +initunix() |
| 324 | +{ |
| 325 | + Egrp *eg = &unixegrp; |
| 326 | + Evalue **ent, *e; |
| 327 | + char *eq, **envp, *line; |
| 328 | + int n; |
| 329 | + |
| 330 | + wlock(&eg->lk); |
| 331 | + |
| 332 | + if(eg->path > 0 || eg->ment > 0 || !environ){ |
| 333 | + // already initialized or nothing in environent |
| 334 | + wunlock(&eg->lk); |
| 335 | + return; |
| 336 | + } |
| 337 | + |
| 338 | + for(envp = environ; *envp != nil; envp++) |
| 339 | + eg->ment++; |
| 340 | + ent = smalloc(sizeof(eg->ent[0])*eg->ment); |
| 341 | + eg->ent = ent; |
| 342 | + |
| 343 | + for(envp = environ; *envp != nil; envp++){ |
| 344 | + line = *envp; |
| 345 | + n = strlen(line); |
| 346 | + |
| 347 | + eq = strchr(line, '='); |
| 348 | + if(eq == nil) |
| 349 | + eq = &line[n]; |
| 350 | + e = smalloc(sizeof(Evalue)); |
| 351 | + e->name = smalloc(eq-line+1); |
| 352 | + strncpy(e->name, line, eq-line); |
| 353 | + |
| 354 | + if(eq[0] != '\0') |
| 355 | + eq++; |
| 356 | + e->len = line+n-eq; |
| 357 | + e->value = smalloc(e->len); |
| 358 | + memmove(e->value, eq, e->len); |
| 359 | + |
| 360 | + e->qid.path = ++eg->path; |
| 361 | + e->qid.vers = 0; |
| 362 | + eg->vers++; |
| 363 | + eg->ent[eg->nent++] = e; |
| 364 | + } |
| 365 | + |
| 366 | + wunlock(&eg->lk); |
| 367 | +} |
| 368 | + |
| 369 | +void |
| 370 | +envcpy(Egrp *to, Egrp *from) |
| 371 | +{ |
| 372 | + int i; |
| 373 | + Evalue *ne, *e; |
| 374 | + |
| 375 | + rlock(&from->lk); |
| 376 | + to->ment = (from->nent+31)&~31; |
| 377 | + to->ent = smalloc(to->ment*sizeof(to->ent[0])); |
| 378 | + for(i=0; i<from->nent; i++){ |
| 379 | + e = from->ent[i]; |
| 380 | + ne = smalloc(sizeof(Evalue)); |
| 381 | + ne->name = smalloc(strlen(e->name)+1); |
| 382 | + strcpy(ne->name, e->name); |
| 383 | + if(e->value){ |
| 384 | + ne->value = smalloc(e->len); |
| 385 | + memmove(ne->value, e->value, e->len); |
| 386 | + ne->len = e->len; |
| 387 | + } |
| 388 | + ne->qid.path = ++to->path; |
| 389 | + to->ent[i] = ne; |
| 390 | + } |
| 391 | + to->nent = from->nent; |
| 392 | + runlock(&from->lk); |
| 393 | +} |
| 394 | + |
| 395 | +void |
| 396 | +closeegrp(Egrp *eg) |
| 397 | +{ |
| 398 | + int i; |
| 399 | + Evalue *e; |
| 400 | + |
| 401 | + if(decref(&eg->ref) == 0){ |
| 402 | + for(i=0; i<eg->nent; i++){ |
| 403 | + e = eg->ent[i]; |
| 404 | + free(e->name); |
| 405 | + if(e->value) |
| 406 | + free(e->value); |
| 407 | + free(e); |
| 408 | + } |
| 409 | + free(eg->ent); |
| 410 | + free(eg); |
| 411 | + } |
| 412 | +} |
| 413 | + |
| 414 | +static Egrp* |
| 415 | +envgrp(Chan *c) |
| 416 | +{ |
| 417 | + if(c->aux == nil) |
| 418 | + return &unixegrp; |
| 419 | + return c->aux; |
| 420 | +} |
| 421 | + |
| 422 | +static int |
| 423 | +envwriteable(Chan *c) |
| 424 | +{ |
| 425 | + return iseve() || c->aux == nil; |
| 426 | +} |