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/* already in plan9.h #include <sys/types.h> *//* for struct passwd, struct group, struct stat ... */
/* plan9.h is first to get the large file support definitions as early as possible */
#include <plan9.h>
#include <sys/stat.h> /* for stat, umask */
#include <stdlib.h> /* for malloc */
#include <string.h> /* for strcpy, memmove */
#include <pwd.h> /* for getpwnam, getpwuid */
#include <grp.h> /* for getgrnam, getgrgid */
#include <unistd.h> /* for gethostname, pread, pwrite, read, write */
#include <utime.h> /* for utime */
#include <dirent.h> /* for readdir */
#include <errno.h> /* for errno */
#include <stdio.h> /* for remove [sic] */
#include <fcntl.h> /* for O_RDONLY, etc. */
#include <sys/socket.h> /* various networking crud */
#include <netinet/in.h>
#include <netdb.h>
#include <fcall.h>
#include <oldfcall.h>
#include <u9fs.h>
/* #ifndef because can be given in makefile */
#ifndef DEFAULTLOG
#define DEFAULTLOG "/tmp/u9fs.log"
#endif
char *logfile = DEFAULTLOG;
#define S_ISSPECIAL(m) (S_ISCHR(m) || S_ISBLK(m) || S_ISFIFO(m))
enum {
Tdot = 1,
Tdotdot
};
enum {
P9P1,
P9P2000
};
typedef struct User User;
struct User {
int id;
gid_t defaultgid;
char *name;
char **mem; /* group members */
int nmem;
User *next;
};
struct Fid {
int fid;
char *path;
struct stat st;
User *u;
int omode;
DIR *dir;
int diroffset;
int fd;
struct dirent *dirent;
int direof;
Fid *next;
Fid *prev;
int auth;
void *authmagic;
};
void* emalloc(size_t);
void* erealloc(void*, size_t);
char* estrdup(char*);
char* estrpath(char*, char*, int);
void sysfatal(char*, ...);
int okuser(char*);
void rversion(Fcall*, Fcall*);
void rauth(Fcall*, Fcall*);
void rattach(Fcall*, Fcall*);
void rflush(Fcall*, Fcall*);
void rclone(Fcall*, Fcall*);
void rwalk(Fcall*, Fcall*);
void ropen(Fcall*, Fcall*);
void rcreate(Fcall*, Fcall*);
void rread(Fcall*, Fcall*);
void rwrite(Fcall*, Fcall*);
void rclunk(Fcall*, Fcall*);
void rstat(Fcall*, Fcall*);
void rwstat(Fcall*, Fcall*);
void rclwalk(Fcall*, Fcall*);
void rremove(Fcall*, Fcall*);
User* uname2user(char*);
User* gname2user(char*);
User* uid2user(int);
User* gid2user(int);
Fid* newfid(int, char**);
Fid* oldfidex(int, int, char**);
Fid* oldfid(int, char**);
int fidstat(Fid*, char**);
void freefid(Fid*);
int userchange(User*, char**);
int userwalk(User*, char**, char*, Qid*, char**);
int useropen(Fid*, int, char**);
int usercreate(Fid*, char*, int, long, char**);
int userremove(Fid*, char**);
int userperm(User*, char*, int, int);
int useringroup(User*, User*);
Qid stat2qid(struct stat*);
void getfcallold(int, Fcall*, int);
void putfcallold(int, Fcall*);
char Eauth[] = "authentication failed";
char Ebadfid[] = "fid unknown or out of range";
char Ebadoffset[] = "bad offset in directory read";
char Ebadusefid[] = "bad use of fid";
char Edirchange[] = "wstat can't convert between files and directories";
char Eexist[] = "file or directory already exists";
char Efidactive[] = "fid already in use";
char Enotdir[] = "not a directory";
char Enotingroup[] = "not a member of proposed group";
char Enotowner[] = "only owner can change group in wstat";
char Eperm[] = "permission denied";
char Especial0[] = "already attached without access to special files";
char Especial1[] = "already attached with access to special files";
char Especial[] = "no access to special file";
char Etoolarge[] = "i/o count too large";
char Eunknowngroup[] = "unknown group";
char Eunknownuser[] = "unknown user";
char Ewstatbuffer[] = "bogus wstat buffer";
ulong msize = IOHDRSZ+8192;
uchar* rxbuf;
uchar* txbuf;
void* databuf;
int connected;
int devallowed;
char* autharg;
char* defaultuser;
char hostname[256];
char remotehostname[256];
int chatty9p = 0;
int network = 1;
int old9p = -1;
int authed;
User* none;
Auth *authmethods[] = { /* first is default */
&authrhosts,
&authp9any,
&authnone,
};
Auth *auth;
/*
* frogs: characters not valid in plan9
* filenames, keep this list in sync with
* /sys/src/9/port/chan.c:1656
*/
char isfrog[256]={
/*NUL*/ 1, 1, 1, 1, 1, 1, 1, 1,
/*BKS*/ 1, 1, 1, 1, 1, 1, 1, 1,
/*DLE*/ 1, 1, 1, 1, 1, 1, 1, 1,
/*CAN*/ 1, 1, 1, 1, 1, 1, 1, 1,
['/'] 1,
[0x7f] 1,
};
int groupchange(User *u, User *g, char **ep);
void
getfcallnew(int fd, Fcall *fc, int have)
{
int len;
if(have > BIT32SZ)
sysfatal("cannot happen");
if(have < BIT32SZ && readn(fd, rxbuf+have, BIT32SZ-have) != BIT32SZ-have)
sysfatal("couldn't read message");
len = GBIT32(rxbuf);
if(len <= BIT32SZ)
sysfatal("bogus message");
len -= BIT32SZ;
if(readn(fd, rxbuf+BIT32SZ, len) != len)
sysfatal("short message");
if(convM2S(rxbuf, len+BIT32SZ, fc) != len+BIT32SZ)
sysfatal("badly sized message type %d", rxbuf[0]);
}
void
getfcallold(int fd, Fcall *fc, int have)
{
int len, n;
if(have > 3)
sysfatal("cannot happen");
if(have < 3 && readn(fd, rxbuf, 3-have) != 3-have)
sysfatal("couldn't read message");
len = oldhdrsize(rxbuf[0]);
if(len < 3)
sysfatal("bad message %d", rxbuf[0]);
if(len > 3 && readn(fd, rxbuf+3, len-3) != len-3)
sysfatal("couldn't read message");
n = iosize(rxbuf);
if(readn(fd, rxbuf+len, n) != n)
sysfatal("couldn't read message");
len += n;
if(convM2Sold(rxbuf, len, fc) != len)
sysfatal("badly sized message type %d", rxbuf[0]);
}
void
putfcallnew(int wfd, Fcall *tx)
{
uint n;
if((n = convS2M(tx, txbuf, msize)) == 0)
sysfatal("couldn't format message type %d", tx->type);
if(write(wfd, txbuf, n) != n)
sysfatal("couldn't send message");
}
void
putfcallold(int wfd, Fcall *tx)
{
uint n;
if((n = convS2Mold(tx, txbuf, msize)) == 0)
sysfatal("couldn't format message type %d", tx->type);
if(write(wfd, txbuf, n) != n)
sysfatal("couldn't send message");
}
void
getfcall(int fd, Fcall *fc)
{
if(old9p == 1){
getfcallold(fd, fc, 0);
return;
}
if(old9p == 0){
getfcallnew(fd, fc, 0);
return;
}
/* auto-detect */
if(readn(fd, rxbuf, 3) != 3)
sysfatal("couldn't read message");
/* is it an old (9P1) message? */
if(50 <= rxbuf[0] && rxbuf[0] <= 87 && (rxbuf[0]&1)==0 && GBIT16(rxbuf+1) == 0xFFFF){
old9p = 1;
getfcallold(fd, fc, 3);
return;
}
getfcallnew(fd, fc, 3);
old9p = 0;
}
void
seterror(Fcall *f, char *error)
{
f->type = Rerror;
f->ename = error ? error : "programmer error";
}
int
isowner(User *u, Fid *f)
{
return u->id == f->st.st_uid;
}
void
serve(int rfd, int wfd)
{
Fcall rx, tx;
for(;;){
getfcall(rfd, &rx);
if(chatty9p)
fprint(2, "<- %F\n", &rx);
memset(&tx, 0, sizeof tx);
tx.type = rx.type+1;
tx.tag = rx.tag;
switch(rx.type){
case Tflush:
break;
case Tversion:
rversion(&rx, &tx);
break;
case Tauth:
rauth(&rx, &tx);
break;
case Tattach:
rattach(&rx, &tx);
break;
case Twalk:
rwalk(&rx, &tx);
break;
case Tstat:
tx.stat = databuf;
rstat(&rx, &tx);
break;
case Twstat:
rwstat(&rx, &tx);
break;
case Topen:
ropen(&rx, &tx);
break;
case Tcreate:
rcreate(&rx, &tx);
break;
case Tread:
tx.data = databuf;
rread(&rx, &tx);
break;
case Twrite:
rwrite(&rx, &tx);
break;
case Tclunk:
rclunk(&rx, &tx);
break;
case Tremove:
rremove(&rx, &tx);
break;
default:
fprint(2, "unknown message %F\n", &rx);
seterror(&tx, "bad message");
break;
}
if(chatty9p)
fprint(2, "-> %F\n", &tx);
(old9p ? putfcallold : putfcallnew)(wfd, &tx);
}
}
void
rversion(Fcall *rx, Fcall *tx)
{
if(msize > rx->msize)
msize = rx->msize;
tx->msize = msize;
if(strncmp(rx->version, "9P", 2) != 0)
tx->version = "unknown";
else
tx->version = "9P2000";
}
void
rauth(Fcall *rx, Fcall *tx)
{
char *e;
if((e = auth->auth(rx, tx)) != nil)
seterror(tx, e);
}
void
rattach(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
User *u;
if(rx->aname == nil)
rx->aname = "";
if(strcmp(rx->aname, "device") == 0){
if(connected && !devallowed){
seterror(tx, Especial0);
return;
}
devallowed = 1;
}else{
if(connected && devallowed){
seterror(tx, Especial1);
return;
}
}
if(strcmp(rx->uname, "none") == 0){
if(authed == 0){
seterror(tx, Eauth);
return;
}
if (none != nil)
rx->uname = none->name;
} else {
if((e = auth->attach(rx, tx)) != nil){
seterror(tx, e);
return;
}
authed++;
}
if((fid = newfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
fid->path = estrdup("/");
if(fidstat(fid, &e) < 0){
seterror(tx, e);
freefid(fid);
return;
}
if(defaultuser)
rx->uname = defaultuser;
if((u = uname2user(rx->uname)) == nil
|| (!defaultuser && u->id == 0)){
/* we don't know anyone named root... */
seterror(tx, Eunknownuser);
freefid(fid);
return;
}
fid->u = u;
tx->qid = stat2qid(&fid->st);
return;
}
void
rwalk(Fcall *rx, Fcall *tx)
{
int i;
char *path, *e;
Fid *fid, *nfid;
e = nil;
if((fid = oldfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
if(fid->omode != -1){
seterror(tx, Ebadusefid);
return;
}
if(fidstat(fid, &e) < 0){
seterror(tx, e);
return;
}
if(!S_ISDIR(fid->st.st_mode) && rx->nwname){
seterror(tx, Enotdir);
return;
}
nfid = nil;
if(rx->newfid != rx->fid && (nfid = newfid(rx->newfid, &e)) == nil){
seterror(tx, e);
return;
}
path = estrdup(fid->path);
e = nil;
for(i=0; i<rx->nwname; i++)
if(userwalk(fid->u, &path, rx->wname[i], &tx->wqid[i], &e) < 0)
break;
if(i == rx->nwname){ /* successful clone or walk */
tx->nwqid = i;
if(nfid){
nfid->path = path;
nfid->u = fid->u;
}else{
free(fid->path);
fid->path = path;
}
}else{
if(i > 0) /* partial walk? */
tx->nwqid = i;
else
seterror(tx, e);
if(nfid) /* clone implicit new fid */
freefid(nfid);
free(path);
}
return;
}
void
ropen(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
if((fid = oldfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
if(fid->omode != -1){
seterror(tx, Ebadusefid);
return;
}
if(fidstat(fid, &e) < 0){
seterror(tx, e);
return;
}
if(!devallowed && S_ISSPECIAL(fid->st.st_mode)){
seterror(tx, Especial);
return;
}
if(useropen(fid, rx->mode, &e) < 0){
seterror(tx, e);
return;
}
tx->iounit = 0;
tx->qid = stat2qid(&fid->st);
}
void
rcreate(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
if((fid = oldfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
if(fid->omode != -1){
seterror(tx, Ebadusefid);
return;
}
if(fidstat(fid, &e) < 0){
seterror(tx, e);
return;
}
if(!S_ISDIR(fid->st.st_mode)){
seterror(tx, Enotdir);
return;
}
if(usercreate(fid, rx->name, rx->mode, rx->perm, &e) < 0){
seterror(tx, e);
return;
}
if(fidstat(fid, &e) < 0){
seterror(tx, e);
return;
}
tx->iounit = 0;
tx->qid = stat2qid(&fid->st);
}
uchar
modebyte(struct stat *st)
{
uchar b;
b = 0;
if(S_ISDIR(st->st_mode))
b |= QTDIR;
/* no way to test append-only */
/* no real way to test exclusive use, but mark devices as such */
if(S_ISSPECIAL(st->st_mode))
b |= QTEXCL;
return b;
}
ulong
plan9mode(struct stat *st)
{
return ((ulong)modebyte(st)<<24) | (st->st_mode & 0777);
}
/*
* this is for chmod, so don't worry about S_IFDIR
*/
mode_t
unixmode(Dir *d)
{
return (mode_t)(d->mode&0777);
}
Qid
stat2qid(struct stat *st)
{
uchar *p, *ep, *q;
Qid qid;
/*
* For now, ignore the device number.
*/
qid.path = 0;
p = (uchar*)&qid.path;
ep = p+sizeof(qid.path);
q = p+sizeof(ino_t);
if(q > ep){
fprint(2, "warning: inode number too big\n");
q = ep;
}
memmove(p, &st->st_ino, q-p);
q = q+sizeof(dev_t);
if(q > ep){
/*
* fprint(2, "warning: inode number + device number too big %d+%d\n",
* sizeof(ino_t), sizeof(dev_t));
*/
q = ep - sizeof(dev_t);
if(q < p)
fprint(2, "warning: device number too big by itself\n");
else
*(dev_t*)q ^= st->st_dev;
}
qid.vers = st->st_mtime ^ (st->st_size << 8);
qid.type = modebyte(st);
return qid;
}
char *
enfrog(char *src)
{
char *d, *dst;
uchar *s;
d = dst = emalloc(strlen(src)*3 + 1);
for (s = (uchar *)src; *s; s++)
if(isfrog[*s] || *s == '\\')
d += sprintf(d, "\\%02x", *s);
else
*d++ = *s;
*d = 0;
return dst;
}
char *
defrog(char *s)
{
char *d, *dst, buf[3];
d = dst = emalloc(strlen(s) + 1);
for(; *s; s++)
if(*s == '\\' && strlen(s) >= 3){
buf[0] = *++s; /* skip \ */
buf[1] = *++s;
buf[2] = 0;
*d++ = strtoul(buf, NULL, 16);
} else
*d++ = *s;
*d = 0;
return dst;
}
void
stat2dir(char *path, struct stat *st, Dir *d)
{
User *u;
char *q, *p, *npath;
memset(d, 0, sizeof(*d));
d->qid = stat2qid(st);
d->mode = plan9mode(st);
d->atime = st->st_atime;
d->mtime = st->st_mtime;
d->length = st->st_size;
d->uid = (u = uid2user(st->st_uid)) ? u->name : "???";
d->gid = (u = gid2user(st->st_gid)) ? u->name : "???";
d->muid = "";
if((q = strrchr(path, '/')) != nil)
d->name = enfrog(q+1);
else
d->name = enfrog(path);
}
void
rread(Fcall *rx, Fcall *tx)
{
char *e, *path;
uchar *p, *ep;
int n;
Fid *fid;
Dir d;
struct stat st;
if(rx->count > msize-IOHDRSZ){
seterror(tx, Etoolarge);
return;
}
if((fid = oldfidex(rx->fid, -1, &e)) == nil){
seterror(tx, e);
return;
}
if (fid->auth) {
char *e;
e = auth->read(rx, tx);
if (e)
seterror(tx, e);
return;
}
if(fid->omode == -1 || (fid->omode&3) == OWRITE){
seterror(tx, Ebadusefid);
return;
}
if(fid->dir){
if(rx->offset != fid->diroffset){
if(rx->offset != 0){
seterror(tx, Ebadoffset);
return;
}
rewinddir(fid->dir);
fid->diroffset = 0;
fid->direof = 0;
}
if(fid->direof){
tx->count = 0;
return;
}
p = (uchar*)tx->data;
ep = (uchar*)tx->data+rx->count;
for(;;){
if(p+BIT16SZ >= ep)
break;
if(fid->dirent == nil) /* one entry cache for when convD2M fails */
if((fid->dirent = readdir(fid->dir)) == nil){
fid->direof = 1;
break;
}
if(strcmp(fid->dirent->d_name, ".") == 0
|| strcmp(fid->dirent->d_name, "..") == 0){
fid->dirent = nil;
continue;
}
path = estrpath(fid->path, fid->dirent->d_name, 0);
memset(&st, 0, sizeof st);
if(stat(path, &st) < 0){
fprint(2, "dirread: stat(%s) failed: %s\n", path, strerror(errno));
fid->dirent = nil;
free(path);
continue;
}
free(path);
stat2dir(fid->dirent->d_name, &st, &d);
if((n=(old9p ? convD2Mold : convD2M)(&d, p, ep-p)) <= BIT16SZ)
break;
p += n;
fid->dirent = nil;
}
tx->count = p - (uchar*)tx->data;
fid->diroffset += tx->count;
}else{
if((n = pread(fid->fd, tx->data, rx->count, rx->offset)) < 0){
seterror(tx, strerror(errno));
return;
}
tx->count = n;
}
}
void
rwrite(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
int n;
if(rx->count > msize-IOHDRSZ){
seterror(tx, Etoolarge);
return;
}
if((fid = oldfidex(rx->fid, -1, &e)) == nil){
seterror(tx, e);
return;
}
if (fid->auth) {
char *e;
e = auth->write(rx, tx);
if (e)
seterror(tx, e);
return;
}
if(fid->omode == -1 || (fid->omode&3) == OREAD || (fid->omode&3) == OEXEC){
seterror(tx, Ebadusefid);
return;
}
if((n = pwrite(fid->fd, rx->data, rx->count, rx->offset)) < 0){
seterror(tx, strerror(errno));
return;
}
tx->count = n;
}
void
rclunk(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
if((fid = oldfidex(rx->fid, -1, &e)) == nil){
seterror(tx, e);
return;
}
if (fid->auth) {
if (auth->clunk) {
e = (*auth->clunk)(rx, tx);
if (e) {
seterror(tx, e);
return;
}
}
}
else if(fid->omode != -1 && fid->omode&ORCLOSE)
remove(fid->path);
freefid(fid);
}
void
rremove(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
if((fid = oldfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
if(userremove(fid, &e) < 0)
seterror(tx, e);
freefid(fid);
}
void
rstat(Fcall *rx, Fcall *tx)
{
char *e;
Fid *fid;
Dir d;
if((fid = oldfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
if(fidstat(fid, &e) < 0){
seterror(tx, e);
return;
}
stat2dir(fid->path, &fid->st, &d);
if((tx->nstat=(old9p ? convD2Mold : convD2M)(&d, tx->stat, msize)) <= BIT16SZ)
seterror(tx, "convD2M fails");
}
void
rwstat(Fcall *rx, Fcall *tx)
{
char *e;
char *p, *old, *new, *dir;
gid_t gid;
Dir d;
Fid *fid;
if((fid = oldfid(rx->fid, &e)) == nil){
seterror(tx, e);
return;
}
/*
* wstat is supposed to be atomic.
* we check all the things we can before trying anything.
* still, if we are told to truncate a file and rename it and only
* one works, we're screwed. in such cases we leave things
* half broken and return an error. it's hardly perfect.
*/
if((old9p ? convM2Dold : convM2D)(rx->stat, rx->nstat, &d, (char*)rx->stat) <= BIT16SZ){
seterror(tx, Ewstatbuffer);
return;
}
if(fidstat(fid, &e) < 0){
seterror(tx, e);
return;
}
/*
* The casting is necessary because d.mode is ulong and might,
* on some systems, be 64 bits. We only want to compare the
* bottom 32 bits, since that's all that gets sent in the protocol.
*
* Same situation for d.mtime and d.length (although that last check
* is admittedly superfluous, given the current lack of 128-bit machines).
*/
gid = (gid_t)-1;
if(d.gid[0] != '\0'){
User *g;
g = gname2user(d.gid);
if(g == nil){
seterror(tx, Eunknowngroup);
return;
}
gid = (gid_t)g->id;
if(groupchange(fid->u, gid2user(gid), &e) < 0){
seterror(tx, e);
return;
}
}
if((u32int)d.mode != (u32int)~0 && (((d.mode&DMDIR)!=0) ^ (S_ISDIR(fid->st.st_mode)!=0))){
seterror(tx, Edirchange);
return;
}
if(strcmp(fid->path, "/") == 0){
seterror(tx, "no wstat of root");
return;
}
/*
* try things in increasing order of harm to the file.
* mtime should come after truncate so that if you
* do both the mtime actually takes effect, but i'd rather
* leave truncate until last.
* (see above comment about atomicity).
*/
if((u32int)d.mode != (u32int)~0 && chmod(fid->path, unixmode(&d)) < 0){
if(chatty9p)
fprint(2, "chmod(%s, 0%luo) failed\n", fid->path, unixmode(&d));
seterror(tx, strerror(errno));
return;
}
if((u32int)d.mtime != (u32int)~0){
struct utimbuf t;
t.actime = 0;
t.modtime = d.mtime;
if(utime(fid->path, &t) < 0){
if(chatty9p)
fprint(2, "utime(%s) failed\n", fid->path);
seterror(tx, strerror(errno));
return;
}
}
if(gid != (gid_t)-1 && gid != fid->st.st_gid){
if(chown(fid->path, (uid_t)-1, gid) < 0){
if(chatty9p)
fprint(2, "chgrp(%s, %d) failed\n", fid->path, gid);
seterror(tx, strerror(errno));
return;
}
}
if(d.name[0]){
old = fid->path;
dir = estrdup(fid->path);
if((p = strrchr(dir, '/')) > dir)
*p = '\0';
else{
seterror(tx, "whoops: can't happen in u9fs");
return;
}
new = estrpath(dir, d.name, 1);
if(strcmp(old, new) != 0 && rename(old, new) < 0){
if(chatty9p)
fprint(2, "rename(%s, %s) failed\n", old, new);
seterror(tx, strerror(errno));
free(new);
free(dir);
return;
}
fid->path = new;
free(old);
free(dir);
}
if((u64int)d.length != (u64int)~0 && truncate(fid->path, d.length) < 0){
fprint(2, "truncate(%s, %lld) failed\n", fid->path, d.length);
seterror(tx, strerror(errno));
return;
}
}
/*
* we keep a table by numeric id. by name lookups happen infrequently
* while by-number lookups happen once for every directory entry read
* and every stat request.
*/
User *utab[64];
User *gtab[64];
User*
adduser(struct passwd *p)
{
User *u;
u = emalloc(sizeof(*u));
u->id = p->pw_uid;
u->name = estrdup(p->pw_name);
u->next = utab[p->pw_uid%nelem(utab)];
u->defaultgid = p->pw_gid;
utab[p->pw_uid%nelem(utab)] = u;
return u;
}
int
useringroup(User *u, User *g)
{
int i;
for(i=0; i<g->nmem; i++)
if(strcmp(g->mem[i], u->name) == 0)
return 1;
/*
* Hack around common Unix problem that everyone has
* default group "user" but /etc/group lists no members.
*/
if(u->defaultgid == g->id)
return 1;
return 0;
}
User*
addgroup(struct group *g)
{
User *u;
char **p;
int n;
u = emalloc(sizeof(*u));
n = 0;
for(p=g->gr_mem; *p; p++)
n++;
u->mem = emalloc(sizeof(u->mem[0])*n);
n = 0;
for(p=g->gr_mem; *p; p++)
u->mem[n++] = estrdup(*p);
u->nmem = n;
u->id = g->gr_gid;
u->name = estrdup(g->gr_name);
u->next = gtab[g->gr_gid%nelem(gtab)];
gtab[g->gr_gid%nelem(gtab)] = u;
return u;
}
User*
uname2user(char *name)
{
int i;
User *u;
struct passwd *p;
for(i=0; i<nelem(utab); i++)
for(u=utab[i]; u; u=u->next)
if(strcmp(u->name, name) == 0)
return u;
if((p = getpwnam(name)) == nil)
return nil;
return adduser(p);
}
User*
uid2user(int id)
{
User *u;
struct passwd *p;
for(u=utab[id%nelem(utab)]; u; u=u->next)
if(u->id == id)
return u;
if((p = getpwuid(id)) == nil)
return nil;
return adduser(p);
}
User*
gname2user(char *name)
{
int i;
User *u;
struct group *g;
for(i=0; i<nelem(gtab); i++)
for(u=gtab[i]; u; u=u->next)
if(strcmp(u->name, name) == 0)
return u;
if((g = getgrnam(name)) == nil)
return nil;
return addgroup(g);
}
User*
gid2user(int id)
{
User *u;
struct group *g;
for(u=gtab[id%nelem(gtab)]; u; u=u->next)
if(u->id == id)
return u;
if((g = getgrgid(id)) == nil)
return nil;
return addgroup(g);
}
void
sysfatal(char *fmt, ...)
{
char buf[1024];
va_list va, temp;
va_start(va, fmt);
va_copy(temp, va);
doprint(buf, buf+sizeof buf, fmt, &temp);
va_end(temp);
va_end(va);
fprint(2, "u9fs: %s\n", buf);
fprint(2, "last unix error: %s\n", strerror(errno));
exit(1);
}
void*
emalloc(size_t n)
{
void *p;
if(n == 0)
n = 1;
p = malloc(n);
if(p == 0)
sysfatal("malloc(%ld) fails", (long)n);
memset(p, 0, n);
return p;
}
void*
erealloc(void *p, size_t n)
{
if(p == 0)
p = malloc(n);
else
p = realloc(p, n);
if(p == 0)
sysfatal("realloc(..., %ld) fails", (long)n);
return p;
}
char*
estrdup(char *p)
{
p = strdup(p);
if(p == 0)
sysfatal("strdup(%.20s) fails", p);
return p;
}
char*
estrpath(char *p, char *q, int frog)
{
char *r, *s;
if(strcmp(q, "..") == 0){
r = estrdup(p);
if((s = strrchr(r, '/')) && s > r)
*s = '\0';
else if(s == r)
s[1] = '\0';
return r;
}
if(frog)
q = defrog(q);
else
q = strdup(q);
r = emalloc(strlen(p)+1+strlen(q)+1);
strcpy(r, p);
if(r[0]=='\0' || r[strlen(r)-1] != '/')
strcat(r, "/");
strcat(r, q);
free(q);
return r;
}
Fid *fidtab[1];
Fid*
lookupfid(int fid)
{
Fid *f;
for(f=fidtab[fid%nelem(fidtab)]; f; f=f->next)
if(f->fid == fid)
return f;
return nil;
}
Fid*
newfid(int fid, char **ep)
{
Fid *f;
if(lookupfid(fid) != nil){
*ep = Efidactive;
return nil;
}
f = emalloc(sizeof(*f));
f->next = fidtab[fid%nelem(fidtab)];
if(f->next)
f->next->prev = f;
fidtab[fid%nelem(fidtab)] = f;
f->fid = fid;
f->fd = -1;
f->omode = -1;
return f;
}
Fid*
newauthfid(int fid, void *magic, char **ep)
{
Fid *af;
af = newfid(fid, ep);
if (af == nil)
return nil;
af->auth = 1;
af->authmagic = magic;
return af;
}
Fid*
oldfidex(int fid, int auth, char **ep)
{
Fid *f;
if((f = lookupfid(fid)) == nil){
*ep = Ebadfid;
return nil;
}
if (auth != -1 && f->auth != auth) {
*ep = Ebadfid;
return nil;
}
if (!f->auth) {
if(userchange(f->u, ep) < 0)
return nil;
}
return f;
}
Fid*
oldfid(int fid, char **ep)
{
return oldfidex(fid, 0, ep);
}
Fid*
oldauthfid(int fid, void **magic, char **ep)
{
Fid *af;
af = oldfidex(fid, 1, ep);
if (af == nil)
return nil;
*magic = af->authmagic;
return af;
}
void
freefid(Fid *f)
{
if(f->prev)
f->prev->next = f->next;
else
fidtab[f->fid%nelem(fidtab)] = f->next;
if(f->next)
f->next->prev = f->prev;
if(f->dir)
closedir(f->dir);
if(f->fd)
close(f->fd);
free(f->path);
free(f);
}
int
fidstat(Fid *fid, char **ep)
{
if(stat(fid->path, &fid->st) < 0){
fprint(2, "fidstat(%s) failed\n", fid->path);
if(ep)
*ep = strerror(errno);
return -1;
}
if(S_ISDIR(fid->st.st_mode))
fid->st.st_size = 0;
return 0;
}
int
userchange(User *u, char **ep)
{
if(defaultuser)
return 0;
if(setreuid(0, 0) < 0){
fprint(2, "setreuid(0, 0) failed\n");
*ep = "cannot setuid back to root";
return -1;
}
/*
* Initgroups does not appear to be SUSV standard.
* But it exists on SGI and on Linux, which makes me
* think it's standard enough. We have to do something
* like this, and the closest other function I can find is
* setgroups (which initgroups eventually calls).
* Setgroups is the same as far as standardization though,
* so we're stuck using a non-SUSV call. Sigh.
*/
if(initgroups(u->name, u->defaultgid) < 0)
fprint(2, "initgroups(%s) failed: %s\n", u->name, strerror(errno));
if(setreuid(-1, u->id) < 0){
fprint(2, "setreuid(-1, %s) failed\n", u->name);
*ep = strerror(errno);
return -1;
}
return 0;
}
/*
* We do our own checking here, then switch to root temporarily
* to set our gid. In a perfect world, you'd be allowed to set your
* egid to any of the supplemental groups of your euid, but this
* is not the case on Linux 2.2.14 (and perhaps others).
*
* This is a race, of course, but it's a race against processes
* that can edit the group lists. If you can do that, you can
* change your own group without our help.
*/
int
groupchange(User *u, User *g, char **ep)
{
if(g == nil)
return -1;
if(!useringroup(u, g)){
if(chatty9p)
fprint(2, "%s not in group %s\n", u->name, g->name);
*ep = Enotingroup;
return -1;
}
setreuid(0,0);
if(setregid(-1, g->id) < 0){
fprint(2, "setegid(%s/%d) failed in groupchange\n", g->name, g->id);
*ep = strerror(errno);
return -1;
}
if(userchange(u, ep) < 0)
return -1;
return 0;
}
/*
* An attempt to enforce permissions by looking at the
* file system. Separation of checking permission and
* actually performing the action is a terrible idea, of
* course, so we use setreuid for most of the permission
* enforcement. This is here only so we can give errors
* on open(ORCLOSE) in some cases.
*/
int
userperm(User *u, char *path, int type, int need)
{
char *p, *q;
int i, have;
struct stat st;
User *g;
switch(type){
default:
fprint(2, "bad type %d in userperm\n", type);
return -1;
case Tdot:
if(stat(path, &st) < 0){
fprint(2, "userperm: stat(%s) failed\n", path);
return -1;
}
break;
case Tdotdot:
p = estrdup(path);
if((q = strrchr(p, '/'))==nil){
fprint(2, "userperm(%s, ..): bad path\n", p);
free(p);
return -1;
}
if(q > p)
*q = '\0';
else
*(q+1) = '\0';
if(stat(p, &st) < 0){
fprint(2, "userperm: stat(%s) (dotdot of %s) failed\n",
p, path);
free(p);
return -1;
}
free(p);
break;
}
if(u == none){
fprint(2, "userperm: none wants %d in 0%luo\n", need, st.st_mode);
have = st.st_mode&7;
if((have&need)==need)
return 0;
return -1;
}
have = st.st_mode&7;
if((uid_t)u->id == st.st_uid)
have |= (st.st_mode>>6)&7;
if((have&need)==need)
return 0;
if(((have|((st.st_mode>>3)&7))&need) != need) /* group won't help */
return -1;
g = gid2user(st.st_gid);
for(i=0; i<g->nmem; i++){
if(strcmp(g->mem[i], u->name) == 0){
have |= (st.st_mode>>3)&7;
break;
}
}
if((have&need)==need)
return 0;
return -1;
}
int
userwalk(User *u, char **path, char *elem, Qid *qid, char **ep)
{
char *npath;
struct stat st;
npath = estrpath(*path, elem, 1);
if(stat(npath, &st) < 0){
free(npath);
*ep = strerror(errno);
return -1;
}
*qid = stat2qid(&st);
free(*path);
*path = npath;
return 0;
}
int
useropen(Fid *fid, int omode, char **ep)
{
int a, o;
/*
* Check this anyway, to try to head off problems later.
*/
if((omode&ORCLOSE) && userperm(fid->u, fid->path, Tdotdot, W_OK) < 0){
*ep = Eperm;
return -1;
}
switch(omode&3){
default:
*ep = "programmer error";
return -1;
case OREAD:
a = R_OK;
o = O_RDONLY;
break;
case ORDWR:
a = R_OK|W_OK;
o = O_RDWR;
break;
case OWRITE:
a = W_OK;
o = O_WRONLY;
break;
case OEXEC:
a = X_OK;
o = O_RDONLY;
break;
}
if(omode & OTRUNC){
a |= W_OK;
o |= O_TRUNC;
}
if(S_ISDIR(fid->st.st_mode)){
if(a != R_OK){
fprint(2, "attempt by %s to open dir %d\n", fid->u->name, omode);
*ep = Eperm;
return -1;
}
if((fid->dir = opendir(fid->path)) == nil){
*ep = strerror(errno);
return -1;
}
}else{
/*
* This is wrong because access used the real uid
* and not the effective uid. Let the open sort it out.
*
if(access(fid->path, a) < 0){
*ep = strerror(errno);
return -1;
}
*
*/
if((fid->fd = open(fid->path, o)) < 0){
*ep = strerror(errno);
return -1;
}
}
fid->omode = omode;
return 0;
}
int
usercreate(Fid *fid, char *elem, int omode, long perm, char **ep)
{
int o, m;
char *opath, *npath;
struct stat st, parent;
if(stat(fid->path, &parent) < 0){
*ep = strerror(errno);
return -1;
}
/*
* Change group so that created file has expected group
* by Plan 9 semantics. If that fails, might as well go
* with the user's default group.
*/
if(groupchange(fid->u, gid2user(parent.st_gid), ep) < 0
&& groupchange(fid->u, gid2user(fid->u->defaultgid), ep) < 0)
return -1;
m = (perm & DMDIR) ? 0777 : 0666;
perm = perm & (~m | (fid->st.st_mode & m));
npath = estrpath(fid->path, elem, 1);
if(perm & DMDIR){
if((omode&~ORCLOSE) != OREAD){
*ep = Eperm;
free(npath);
return -1;
}
if(stat(npath, &st) >= 0 || errno != ENOENT){
*ep = Eexist;
free(npath);
return -1;
}
/* race */
if(mkdir(npath, (perm|0400)&0777) < 0){
*ep = strerror(errno);
free(npath);
return -1;
}
if((fid->dir = opendir(npath)) == nil){
*ep = strerror(errno);
remove(npath); /* race */
free(npath);
return -1;
}
}else{
o = O_CREAT|O_EXCL;
switch(omode&3){
default:
*ep = "programmer error";
return -1;
case OREAD:
case OEXEC:
o |= O_RDONLY;
break;
case ORDWR:
o |= O_RDWR;
break;
case OWRITE:
o |= O_WRONLY;
break;
}
if(omode & OTRUNC)
o |= O_TRUNC;
if((fid->fd = open(npath, o, perm&0777)) < 0){
if(chatty9p)
fprint(2, "create(%s, 0x%x, 0%o) failed\n", npath, o, perm&0777);
*ep = strerror(errno);
free(npath);
return -1;
}
}
opath = fid->path;
fid->path = npath;
if(fidstat(fid, ep) < 0){
fprint(2, "stat after create on %s failed\n", npath);
remove(npath); /* race */
free(npath);
fid->path = opath;
if(fid->fd >= 0){
close(fid->fd);
fid->fd = -1;
}else{
closedir(fid->dir);
fid->dir = nil;
}
return -1;
}
fid->omode = omode;
free(opath);
return 0;
}
int
userremove(Fid *fid, char **ep)
{
if(remove(fid->path) < 0){
*ep = strerror(errno);
return -1;
}
return 0;
}
void
usage(void)
{
fprint(2, "usage: u9fs [-Dnz] [-a authmethod] [-m msize] [-u user] [root]\n");
exit(1);
}
int
main(int argc, char **argv)
{
char *authtype;
int i;
int fd;
int logflag;
auth = authmethods[0];
logflag = O_WRONLY|O_APPEND|O_CREAT;
ARGBEGIN{
case 'D':
chatty9p = 1;
break;
case 'a':
authtype = EARGF(usage());
auth = nil;
for(i=0; i<nelem(authmethods); i++)
if(strcmp(authmethods[i]->name, authtype)==0)
auth = authmethods[i];
if(auth == nil)
sysfatal("unknown auth type '%s'", authtype);
break;
case 'A':
autharg = EARGF(usage());
break;
case 'l':
logfile = EARGF(usage());
break;
case 'm':
msize = strtol(EARGF(usage()), 0, 0);
break;
case 'n':
network = 0;
break;
case 'u':
defaultuser = EARGF(usage());
break;
case 'z':
logflag |= O_TRUNC;
}ARGEND
if(argc > 1)
usage();
fd = open(logfile, logflag, 0666);
if(fd < 0)
sysfatal("cannot open log '%s'", logfile);
if(dup2(fd, 2) < 0)
sysfatal("cannot dup fd onto stderr");
fprint(2, "u9fs\nkill %d\n", (int)getpid());
fmtinstall('F', fcallconv);
fmtinstall('D', dirconv);
fmtinstall('M', dirmodeconv);
rxbuf = emalloc(msize);
txbuf = emalloc(msize);
databuf = emalloc(msize);
if(auth->init)
auth->init();
if(network)
getremotehostname(remotehostname, sizeof remotehostname);
if(gethostname(hostname, sizeof hostname) < 0)
strcpy(hostname, "gnot");
umask(0);
if(argc == 1)
if(chroot(argv[0]) < 0)
sysfatal("chroot '%s' failed", argv[0]);
none = uname2user("none");
if(none == nil)
none = uname2user("nobody");
serve(0, 1);
return 0;
}