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- #include "u.h"
- #include "../port/lib.h"
- #include "mem.h"
- #include "dat.h"
- #include "fns.h"
- #include "../port/error.h"
- typedef struct Srv Srv;
- struct Srv
- {
- char *name;
- char *owner;
- ulong perm;
- Chan *chan;
- Srv *link;
- ulong path;
- };
- static QLock srvlk;
- static Srv *srv;
- static int qidpath;
- static int
- srvgen(Chan *c, char*, Dirtab*, int, int s, Dir *dp)
- {
- Srv *sp;
- Qid q;
- if(s == DEVDOTDOT){
- devdir(c, c->qid, "#s", 0, eve, 0555, dp);
- return 1;
- }
- qlock(&srvlk);
- for(sp = srv; sp && s; sp = sp->link)
- s--;
- if(sp == 0) {
- qunlock(&srvlk);
- return -1;
- }
- mkqid(&q, sp->path, 0, QTFILE);
- /* make sure name string continues to exist after we release lock */
- kstrcpy(up->genbuf, sp->name, sizeof up->genbuf);
- devdir(c, q, up->genbuf, 0, sp->owner, sp->perm, dp);
- qunlock(&srvlk);
- return 1;
- }
- static void
- srvinit(void)
- {
- qidpath = 1;
- }
- static Chan*
- srvattach(char *spec)
- {
- return devattach('s', spec);
- }
- static Walkqid*
- srvwalk(Chan *c, Chan *nc, char **name, int nname)
- {
- return devwalk(c, nc, name, nname, 0, 0, srvgen);
- }
- static Srv*
- srvlookup(char *name, ulong qidpath)
- {
- Srv *sp;
- for(sp = srv; sp; sp = sp->link)
- if(sp->path == qidpath || (name && strcmp(sp->name, name) == 0))
- return sp;
- return nil;
- }
- static int
- srvstat(Chan *c, uchar *db, int n)
- {
- return devstat(c, db, n, 0, 0, srvgen);
- }
- char*
- srvname(Chan *c)
- {
- Srv *sp;
- char *s;
- for(sp = srv; sp; sp = sp->link)
- if(sp->chan == c){
- s = smalloc(3+strlen(sp->name)+1);
- sprint(s, "#s/%s", sp->name);
- return s;
- }
- return nil;
- }
- static Chan*
- srvopen(Chan *c, int omode)
- {
- Srv *sp;
- if(c->qid.type == QTDIR){
- if(omode & ORCLOSE)
- error(Eperm);
- if(omode != OREAD)
- error(Eisdir);
- c->mode = omode;
- c->flag |= COPEN;
- c->offset = 0;
- return c;
- }
- qlock(&srvlk);
- if(waserror()){
- qunlock(&srvlk);
- nexterror();
- }
- sp = srvlookup(nil, c->qid.path);
- if(sp == 0 || sp->chan == 0)
- error(Eshutdown);
- if(omode&OTRUNC)
- error("srv file already exists");
- if(openmode(omode)!=sp->chan->mode && sp->chan->mode!=ORDWR)
- error(Eperm);
- devpermcheck(sp->owner, sp->perm, omode);
- cclose(c);
- incref(sp->chan);
- qunlock(&srvlk);
- poperror();
- return sp->chan;
- }
- static void
- srvcreate(Chan *c, char *name, int omode, ulong perm)
- {
- Srv *sp;
- if(openmode(omode) != OWRITE)
- error(Eperm);
- if(omode & OCEXEC) /* can't happen */
- panic("someone broke namec");
- sp = malloc(sizeof(Srv));
- if(sp == 0)
- error(Enomem);
- qlock(&srvlk);
- if(waserror()){
- free(sp);
- qunlock(&srvlk);
- nexterror();
- }
- if(srvlookup(name, -1))
- error(Eexist);
- sp->path = qidpath++;
- sp->link = srv;
- c->qid.type = QTFILE;
- c->qid.path = sp->path;
- srv = sp;
- qunlock(&srvlk);
- poperror();
- sp->name = smalloc(strlen(name)+1);
- strcpy(sp->name, name);
- kstrdup(&sp->owner, up->user);
- sp->perm = perm&0777;
- c->flag |= COPEN;
- c->mode = OWRITE;
- }
- static void
- srvremove(Chan *c)
- {
- Srv *sp, **l;
- if(c->qid.type == QTDIR)
- error(Eperm);
- qlock(&srvlk);
- if(waserror()){
- qunlock(&srvlk);
- nexterror();
- }
- l = &srv;
- for(sp = *l; sp; sp = sp->link) {
- if(sp->path == c->qid.path)
- break;
- l = &sp->link;
- }
- if(sp == 0)
- error(Enonexist);
- if(strcmp(sp->name, "boot") == 0)
- error(Eperm);
- *l = sp->link;
- qunlock(&srvlk);
- poperror();
- if(sp->chan)
- cclose(sp->chan);
- if(sp->name){
- free(sp->name);
- sp->name = nil;
- }
- free(sp);
- }
- static int
- srvwstat(Chan *c, uchar *dp, int n)
- {
- Dir d;
- Srv *sp;
- if(c->qid.type & QTDIR)
- error(Eperm);
- qlock(&srvlk);
- if(waserror()){
- qunlock(&srvlk);
- nexterror();
- }
- sp = srvlookup(nil, c->qid.path);
- if(sp == 0)
- error(Enonexist);
- if(strcmp(sp->owner, up->user) && !iseve())
- error(Eperm);
- n = convM2D(dp, n, &d, nil);
- if(n == 0)
- error (Eshortstat);
- if(d.mode != ~0UL)
- sp->perm = d.mode & 0777;
- if(d.uid && *d.uid)
- kstrdup(&sp->owner, d.uid);
- qunlock(&srvlk);
- poperror();
- return n;
- }
- static void
- srvclose(Chan *c)
- {
- /*
- * in theory we need to override any changes in removability
- * since open, but since all that's checked is the owner,
- * which is immutable, all is well.
- */
- if(c->flag & CRCLOSE){
- if(waserror())
- return;
- srvremove(c);
- poperror();
- }
- }
- static long
- srvread(Chan *c, void *va, long n, vlong)
- {
- isdir(c);
- return devdirread(c, va, n, 0, 0, srvgen);
- }
- static long
- srvwrite(Chan *c, void *va, long n, vlong)
- {
- Srv *sp;
- Chan *c1;
- int fd;
- char buf[32];
- if(n >= sizeof buf)
- error(Egreg);
- memmove(buf, va, n); /* so we can NUL-terminate */
- buf[n] = 0;
- fd = strtoul(buf, 0, 0);
- c1 = fdtochan(fd, -1, 0, 1); /* error check and inc ref */
- qlock(&srvlk);
- if(waserror()) {
- qunlock(&srvlk);
- cclose(c1);
- nexterror();
- }
- if(c1->flag & (CCEXEC|CRCLOSE))
- error("posted fd has remove-on-close or close-on-exec");
- if(c1->qid.type & QTAUTH)
- error("can't post auth file in srv");
- sp = srvlookup(nil, c->qid.path);
- if(sp == 0)
- error(Enonexist);
- if(sp->chan)
- error(Ebadusefd);
- sp->chan = c1;
- qunlock(&srvlk);
- poperror();
- return n;
- }
- Dev srvdevtab = {
- 's',
- "srv",
- devreset,
- srvinit,
- devshutdown,
- srvattach,
- srvwalk,
- srvstat,
- srvopen,
- srvcreate,
- srvclose,
- srvread,
- devbread,
- srvwrite,
- devbwrite,
- srvremove,
- srvwstat,
- };
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