1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
#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;
}
|
