ref: dfec09c436a8a328fc97007cf2dc3cd5476cc748
dir: /sys/src/9/port/devsrv.c/
#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 Srv* srvlookup(char *name, ulong qidpath) { Srv *sp; for(sp = srv; sp != nil; sp = sp->link) { if(sp->path == qidpath || (name != nil && strcmp(sp->name, name) == 0)) return sp; } return nil; } static int srvgen(Chan *c, char *name, 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); if(name != nil) sp = srvlookup(name, -1); else { for(sp = srv; sp != nil && s > 0; sp = sp->link) s--; } if(sp == nil || (name != nil && (strlen(sp->name) >= sizeof(up->genbuf)))) { 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 int srvstat(Chan *c, uchar *db, int n) { return devstat(c, db, n, 0, 0, srvgen); } char* srvname(Chan *c) { Srv *sp; char *s; s = nil; qlock(&srvlk); for(sp = srv; sp != nil; sp = sp->link) { if(sp->chan == c){ s = malloc(3+strlen(sp->name)+1); if(s != nil) sprint(s, "#s/%s", sp->name); break; } } qunlock(&srvlk); return s; } static Chan* srvopen(Chan *c, int omode) { Srv *sp; Chan *nc; 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 == nil || sp->chan == nil) error(Eshutdown); if(omode&OTRUNC) error(Eexist); if(openmode(omode)!=sp->chan->mode && sp->chan->mode!=ORDWR) error(Eperm); devpermcheck(sp->owner, sp->perm, omode); nc = sp->chan; incref(nc); qunlock(&srvlk); poperror(); cclose(c); return nc; } static Chan* srvcreate(Chan *c, char *name, int omode, ulong perm) { Srv *sp; if(openmode(omode) != OWRITE) error(Eperm); if(strlen(name) >= sizeof(up->genbuf)) error(Etoolong); sp = smalloc(sizeof *sp); kstrdup(&sp->name, name); kstrdup(&sp->owner, up->user); qlock(&srvlk); if(waserror()){ qunlock(&srvlk); free(sp->owner); free(sp->name); free(sp); nexterror(); } if(srvlookup(name, -1) != nil) error(Eexist); sp->perm = perm&0777; sp->path = qidpath++; c->qid.path = sp->path; c->qid.type = QTFILE; sp->link = srv; srv = sp; qunlock(&srvlk); poperror(); c->flag |= COPEN; c->mode = OWRITE; return c; } 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 != nil; sp = *l) { if(sp->path == c->qid.path) break; l = &sp->link; } if(sp == nil) error(Enonexist); /* * Only eve can remove system services. */ if(strcmp(sp->owner, eve) == 0 && !iseve()) error(Eperm); /* * No removing personal services. */ if((sp->perm&7) != 7 && strcmp(sp->owner, up->user) && !iseve()) error(Eperm); *l = sp->link; sp->link = nil; qunlock(&srvlk); poperror(); if(sp->chan != nil) cclose(sp->chan); free(sp->owner); free(sp->name); free(sp); } static int srvwstat(Chan *c, uchar *dp, int n) { char *strs; Srv *sp; Dir d; if(c->qid.type & QTDIR) error(Eperm); strs = smalloc(n); if(waserror()){ free(strs); nexterror(); } n = convM2D(dp, n, &d, strs); if(n == 0) error(Eshortstat); qlock(&srvlk); if(waserror()){ qunlock(&srvlk); nexterror(); } sp = srvlookup(nil, c->qid.path); if(sp == nil) error(Enonexist); if(strcmp(sp->owner, up->user) != 0 && !iseve()) error(Eperm); if(d.name != nil && *d.name && strcmp(sp->name, d.name) != 0) { if(strchr(d.name, '/') != nil) error(Ebadchar); if(strlen(d.name) >= sizeof(up->genbuf)) error(Etoolong); kstrdup(&sp->name, d.name); } if(d.uid != nil && *d.uid) kstrdup(&sp->owner, d.uid); if(d.mode != ~0UL) sp->perm = d.mode & 0777; qunlock(&srvlk); poperror(); free(strs); 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(Etoobig); 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("cannot post auth file in srv"); sp = srvlookup(nil, c->qid.path); if(sp == nil) error(Enonexist); if(sp->chan != nil) 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, }; void srvrenameuser(char *old, char *new) { Srv *sp; qlock(&srvlk); for(sp = srv; sp != nil; sp = sp->link) { if(sp->owner != nil && strcmp(old, sp->owner) == 0) kstrdup(&sp->owner, new); } qunlock(&srvlk); }