ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /liblogfs/wstat.c/
#include "logfsos.h" #include "logfs.h" #include "fcall.h" #include "local.h" char * logfsserverwstat(LogfsServer *server, u32int fid, uchar *stat, ushort nstat) { Fid *f; uchar *p; ushort len; uchar *mep; Qid qid; u32int perm, mtime; uvlong length; char *name, *uname, *gname, *muname; int qiddonttouch, permdonttouch, mtimedonttouch, lengthdonttouch; Entry *e, *parent; LogMessage s; char *cuid, *ngid; Group *eg, *ng; char *cname; char *errmsg; char *nuid; if(server->trace > 1) print("logfsserverwstat(%ud, %ud)\n", fid, nstat); if(nstat < 49) return Eshortstat; p = stat; len = GBIT16(p); p += BIT16SZ; if(len + BIT16SZ != nstat) return Eshortstat; mep = p + len; p += BIT16SZ + BIT32SZ; /* skip type and dev */ qid.type = *p++; qid.vers = GBIT32(p); p += BIT32SZ; qid.path = GBIT64(p); p += BIT64SZ; perm = GBIT32(p); p += BIT32SZ; p += BIT32SZ; /* skip atime */ mtime = GBIT32(p); p += BIT32SZ; length = GBIT64(p); p+= BIT64SZ; if(!logfsgn(&p, mep, &name) || !logfsgn(&p, mep, &uname) || !logfsgn(&p, mep, &gname) || !logfsgn(&p, mep, &muname)) return Eshortstat; if(p != mep) return Eshortstat; qiddonttouch = qid.type == (uchar)~0 && qid.vers == ~0 && qid.path == ~(uvlong)0; permdonttouch = perm == ~0; mtimedonttouch = mtime == ~0; lengthdonttouch = length == ~(uvlong)0; if(server->trace > 1) { int comma = 0; print("logfsserverwstat("); if(!qiddonttouch) { comma = 1; print("qid=0x%.2ux/%lud/%llud", qid.type, qid.vers, qid.path); } if(!permdonttouch) { if(comma) print(", "); print("perm=0%uo", perm); comma = 1; } if(!mtimedonttouch) { if(comma) print(", "); print("mtime=%ud", mtime); comma = 1; } if(!lengthdonttouch) { if(comma) print(", "); print("length=%llud", length); comma = 1; } if(name != nil) { if(comma) print(", "); print("name=%s", name); comma = 1; } if(uname != nil) { if(comma) print(", "); print("uid=%s", uname); comma = 1; } if(gname != nil) { if(comma) print(", "); print("gid=%s", gname); comma = 1; } if(muname != nil) { if(comma) print(", "); print("muname=%s", muname); comma = 1; } USED(comma); print(")\n"); } f = logfsfidmapfindentry(server->fidmap, fid); if(f == nil) return logfsebadfid; e = f->entry; if(e->deadandgone) return Eio; parent = e->parent; if(name) { Entry *oe; if(parent == e) return Eperm; if(!logfsuserpermcheck(server, e->parent, f, DMWRITE)) return Eperm; for(oe = parent->u.dir.list; oe; oe = oe->next) { if(oe == e) continue; if(strcmp(oe->name, name) == 0) return Eexist; } } if(!lengthdonttouch) { if(!logfsuserpermcheck(server, e, f, DMWRITE)) return Eperm; if(e->qid.type & QTDIR) { if(length != 0) return Eperm; }else if(length != e->u.file.length){ /* * TODO - truncate directory * TODO - truncate file */ return "wstat -- can't change length"; } } cuid = logfsisfindidfromname(server->is, f->uname); /* TODO - change entries to have a group pointer */ eg = logfsisfindgroupfromid(server->is, e->uid); if(gname) { gname = logfsisustadd(server->is, gname); if(gname == nil) return Enomem; ngid = logfsisfindidfromname(server->is, gname); if(ngid == nil) return Eunknown; } else ngid = nil; if(uname) { uname = logfsisustadd(server->is, uname); if(uname == nil) return Enomem; nuid = logfsisfindidfromname(server->is, uname); if(nuid == nil) return Eunknown; } else nuid = nil; if(!permdonttouch || !mtimedonttouch) { /* * same permissions rules - change by owner, or by group leader */ if((server->openflags & LogfsOpenFlagWstatAllow) == 0 && e->uid != cuid && (eg == nil || !logfsisgroupuidisleader(server->is, eg, cuid))) return Eperm; } if(!permdonttouch){ if((perm^e->perm) & DMDIR) return "wstat -- attempt to change directory"; if(perm & ~(DMDIR|DMAPPEND|DMEXCL|0777)) return Eperm; } if(gname) { int ok; ng = logfsisfindgroupfromid(server->is, ngid); ok = 0; if(e->uid == cuid && logfsisgroupuidismember(server->is, ng, e->uid)) ok = 1; if(!ok && eg && logfsisgroupuidisleader(server->is, eg, cuid) && logfsisgroupuidisleader(server->is, ng, cuid)) ok = 1; if(!ok && (server->openflags & LogfsOpenFlagWstatAllow) == 0) return Eperm; } if(!qiddonttouch) return Eperm; if(uname){ if((server->openflags & LogfsOpenFlagWstatAllow) == 0) return Eperm; } if(muname) return Eperm; /* * we can do this */ if(mtimedonttouch && permdonttouch && lengthdonttouch && name == nil && uname == nil && gname == nil) { /* * but we aren't doing anything - this is a wstat flush */ return logfsserverflush(server); } if(name) { cname = logfsstrdup(name); if(cname == nil) return Enomem; } else cname = nil; /* * send the log message */ s.type = LogfsLogTwstat; s.path = e->qid.path; s.u.wstat.name = cname; s.u.wstat.perm = perm; s.u.wstat.uid = nuid; s.u.wstat.gid = ngid; s.u.wstat.mtime = mtime; s.u.wstat.muid = cuid; errmsg = logfslog(server, 1, &s); if(errmsg) { logfsfreemem(cname); return errmsg; } if(!mtimedonttouch) e->mtime = mtime; if(!permdonttouch) e->perm = (e->perm & DMDIR) | perm; if(!lengthdonttouch) { /* TODO */ } if(name) { logfsfreemem(e->name); e->name = cname; } if(uname) e->uid = nuid; if(ngid) e->gid = ngid; return nil; }