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/*
* exportfs - Export a plan 9 name space across a network
*/
#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include <libsec.h>
#define Extern
#include "exportfs.h"
#define QIDPATH ((1LL<<48)-1)
vlong newqid = 0;
enum {
Encnone,
Encssl,
Enctls,
};
void (*fcalls[])(Fsrpc*) =
{
[Tversion] Xversion,
[Tauth] Xauth,
[Tflush] Xflush,
[Tattach] Xattach,
[Twalk] Xwalk,
[Topen] slave,
[Tcreate] Xcreate,
[Tclunk] Xclunk,
[Tread] slave,
[Twrite] slave,
[Tremove] Xremove,
[Tstat] Xstat,
[Twstat] Xwstat,
};
/* accounting and debugging counters */
int filecnt;
int freecnt;
int qidcnt;
int qfreecnt;
int ncollision;
int netfd; /* initially stdin */
int srvfd = -1;
int nonone = 1;
char *filterp;
char *ealgs = "rc4_256 sha1";
char *aanfilter = "/bin/aan";
int encproto = Encnone;
int readonly;
static void mksecret(char *, uchar *);
static int localread9pmsg(int, void *, uint, ulong *);
static char *anstring = "tcp!*!0";
char *netdir = "", *local = "", *remote = "";
int filter(int, char *);
void
usage(void)
{
fprint(2, "usage: %s [-adnsR] [-f dbgfile] [-m msize] [-r root] "
"[-S srvfile] [-e 'crypt hash'] [-P exclusion-file] "
"[-A announce-string] [-B address]\n", argv0);
fatal("usage");
}
static void
noteconn(int fd)
{
NetConnInfo *nci;
nci = getnetconninfo(nil, fd);
if (nci == nil)
return;
netdir = strdup(nci->dir);
local = strdup(nci->lsys);
remote = strdup(nci->rsys);
freenetconninfo(nci);
}
void
main(int argc, char **argv)
{
char buf[ERRMAX], ebuf[ERRMAX], *srvfdfile;
Fsrpc *r;
int doauth, n, fd;
char *dbfile, *srv, *na, *nsfile, *keyspec;
AuthInfo *ai;
ulong initial;
dbfile = "/tmp/exportdb";
srv = nil;
srvfd = -1;
srvfdfile = nil;
na = nil;
nsfile = nil;
keyspec = "";
doauth = 0;
ai = nil;
ARGBEGIN{
case 'a':
doauth = 1;
break;
case 'd':
dbg++;
break;
case 'e':
ealgs = EARGF(usage());
if(*ealgs == 0 || strcmp(ealgs, "clear") == 0)
ealgs = nil;
break;
case 'f':
dbfile = EARGF(usage());
break;
case 'k':
keyspec = EARGF(usage());
break;
case 'm':
messagesize = strtoul(EARGF(usage()), nil, 0);
break;
case 'n':
nonone = 0;
break;
case 'r':
srv = EARGF(usage());
break;
case 's':
srv = "/";
break;
case 'A':
anstring = EARGF(usage());
break;
case 'B':
na = EARGF(usage());
break;
case 'F':
/* accepted but ignored, for backwards compatibility */
break;
case 'N':
nsfile = EARGF(usage());
break;
case 'P':
patternfile = EARGF(usage());
break;
case 'R':
readonly = 1;
break;
case 'S':
if(srvfdfile)
usage();
srvfdfile = EARGF(usage());
break;
default:
usage();
}ARGEND
USED(argc, argv);
if(doauth){
/*
* We use p9any so we don't have to visit this code again, with the
* cost that this code is incompatible with the old world, which
* requires p9sk2. (The two differ in who talks first, so compatibility
* is awkward.)
*/
ai = auth_proxy(0, auth_getkey, "proto=p9any role=server %s", keyspec);
if(ai == nil)
fatal("auth_proxy: %r");
if(nonone && strcmp(ai->cuid, "none") == 0)
fatal("exportfs by none disallowed");
if(auth_chuid(ai, nsfile) < 0)
fatal("auth_chuid: %r");
putenv("service", "exportfs");
}
if(srvfdfile){
if((srvfd = open(srvfdfile, ORDWR)) < 0)
sysfatal("open '%s': %r", srvfdfile);
}
if(na){
if(srv == nil)
sysfatal("-B requires -s");
local = "me";
remote = na;
if((fd = dial(netmkaddr(na, 0, "importfs"), 0, 0, 0)) < 0)
sysfatal("can't dial %s: %r", na);
ai = auth_proxy(fd, auth_getkey, "proto=p9any role=client %s", keyspec);
if(ai == nil)
sysfatal("%r: %s", na);
dup(fd, 0);
dup(fd, 1);
close(fd);
}
exclusions();
if(dbg) {
n = create(dbfile, OWRITE|OTRUNC, 0666);
dup(n, DFD);
close(n);
}
if(srvfd >= 0 && srv){
fprint(2, "exportfs: -S cannot be used with -r or -s\n");
usage();
}
DEBUG(DFD, "exportfs: started\n");
rfork(RFNOTEG);
if(messagesize == 0){
messagesize = iounit(netfd);
if(messagesize == 0)
messagesize = 8192+IOHDRSZ;
}
Workq = emallocz(sizeof(Fsrpc)*Nr_workbufs);
// for(i=0; i<Nr_workbufs; i++)
// Workq[i].buf = emallocz(messagesize);
fhash = emallocz(sizeof(Fid*)*FHASHSIZE);
fmtinstall('F', fcallfmt);
/*
* Get tree to serve from network connection,
* check we can get there and ack the connection
*/
if(srvfd != -1) {
/* do nothing */
}
else if(srv) {
if(chdir(srv) < 0) {
errstr(ebuf, sizeof ebuf);
fprint(0, "chdir(\"%s\"): %s\n", srv, ebuf);
DEBUG(DFD, "chdir(\"%s\"): %s\n", srv, ebuf);
exits(ebuf);
}
DEBUG(DFD, "invoked as server for %s", srv);
strncpy(buf, srv, sizeof buf);
}
else {
noteconn(netfd);
buf[0] = 0;
n = read(0, buf, sizeof(buf)-1);
if(n < 0) {
errstr(buf, sizeof buf);
fprint(0, "read(0): %s\n", buf);
DEBUG(DFD, "read(0): %s\n", buf);
exits(buf);
}
buf[n] = 0;
if(chdir(buf) < 0) {
errstr(ebuf, sizeof ebuf);
fprint(0, "chdir(%d:\"%s\"): %s\n", n, buf, ebuf);
DEBUG(DFD, "chdir(%d:\"%s\"): %s\n", n, buf, ebuf);
exits(ebuf);
}
}
DEBUG(DFD, "\niniting root\n");
initroot();
DEBUG(DFD, "exportfs: %s\n", buf);
if(srv == nil && srvfd == -1 && write(0, "OK", 2) != 2)
fatal("open ack write");
if (readn(netfd, &initial, sizeof(ulong)) < sizeof(ulong))
fatal("can't read initial string: %r\n");
if (strncmp((char *)&initial, "impo", sizeof(ulong)) == 0) {
char buf[128], *p, *args[3];
/* New import. Read import's parameters... */
initial = 0;
p = buf;
while (p - buf < sizeof buf) {
if ((n = read(netfd, p, 1)) < 0)
fatal("can't read impo arguments: %r\n");
if (n == 0)
fatal("connection closed while reading arguments\n");
if (*p == '\n')
*p = '\0';
if (*p++ == '\0')
break;
}
if (tokenize(buf, args, nelem(args)) != 2)
fatal("impo arguments invalid: impo%s...\n", buf);
if (strcmp(args[0], "aan") == 0)
filterp = aanfilter;
else if (strcmp(args[0], "nofilter") != 0)
fatal("import filter argument unsupported: %s\n", args[0]);
if (strcmp(args[1], "ssl") == 0)
encproto = Encssl;
else if (strcmp(args[1], "tls") == 0)
encproto = Enctls;
else if (strcmp(args[1], "clear") != 0)
fatal("import encryption proto unsupported: %s\n", args[1]);
if (encproto == Enctls)
sysfatal("%s: tls has not yet been implemented", argv[0]);
}
if (encproto != Encnone && ealgs && ai) {
uchar key[16];
uchar digest[SHA1dlen];
char fromclientsecret[21];
char fromserversecret[21];
int i;
memmove(key+4, ai->secret, ai->nsecret);
/* exchange random numbers */
srand(truerand());
for(i = 0; i < 4; i++)
key[i+12] = rand();
if (initial)
fatal("Protocol botch: old import\n");
if(readn(netfd, key, 4) != 4)
fatal("can't read key part; %r\n");
if(write(netfd, key+12, 4) != 4)
fatal("can't write key part; %r\n");
/* scramble into two secrets */
sha1(key, sizeof(key), digest, nil);
mksecret(fromclientsecret, digest);
mksecret(fromserversecret, digest+10);
if (filterp)
netfd = filter(netfd, filterp);
switch (encproto) {
case Encssl:
netfd = pushssl(netfd, ealgs, fromserversecret,
fromclientsecret, nil);
break;
case Enctls:
default:
fatal("Unsupported encryption protocol\n");
}
if(netfd < 0)
fatal("can't establish ssl connection: %r");
}
else if (filterp) {
if (initial)
fatal("Protocol botch: don't know how to deal with this\n");
netfd = filter(netfd, filterp);
}
/*
* Start serving file requests from the network
*/
for(;;) {
r = getsbuf();
if(r == 0)
fatal("Out of service buffers");
n = localread9pmsg(netfd, r->buf, messagesize, &initial);
if(n <= 0)
fatal(nil);
if(convM2S(r->buf, n, &r->work) == 0)
fatal("convM2S format error");
DEBUG(DFD, "%F\n", &r->work);
(fcalls[r->work.type])(r);
}
}
/*
* WARNING: Replace this with the original version as soon as all
* _old_ imports have been replaced with negotiating imports. Also
* cpu relies on this (which needs to be fixed!) -- pb.
*/
static int
localread9pmsg(int fd, void *abuf, uint n, ulong *initial)
{
int m, len;
uchar *buf;
buf = abuf;
/* read count */
assert(BIT32SZ == sizeof(ulong));
if (*initial) {
memcpy(buf, initial, BIT32SZ);
*initial = 0;
}
else {
m = readn(fd, buf, BIT32SZ);
if(m != BIT32SZ){
if(m < 0)
return -1;
return 0;
}
}
len = GBIT32(buf);
if(len <= BIT32SZ || len > n){
werrstr("bad length in 9P2000 message header");
return -1;
}
len -= BIT32SZ;
m = readn(fd, buf+BIT32SZ, len);
if(m < len)
return 0;
return BIT32SZ+m;
}
void
reply(Fcall *r, Fcall *t, char *err)
{
uchar *data;
int n;
t->tag = r->tag;
t->fid = r->fid;
if(err) {
t->type = Rerror;
t->ename = err;
}
else
t->type = r->type + 1;
DEBUG(DFD, "\t%F\n", t);
data = malloc(messagesize); /* not mallocz; no need to clear */
if(data == nil)
fatal(Enomem);
n = convS2M(t, data, messagesize);
if(write(netfd, data, n)!=n)
{syslog(0, "exportfs", "short write: %r");
fatal("mount write");
}
free(data);
}
Fid *
getfid(int nr)
{
Fid *f;
for(f = fidhash(nr); f; f = f->next)
if(f->nr == nr)
return f;
return 0;
}
int
freefid(int nr)
{
Fid *f, **l;
char buf[128];
l = &fidhash(nr);
for(f = *l; f; f = f->next) {
if(f->nr == nr) {
if(f->mid) {
sprint(buf, "/mnt/exportfs/%d", f->mid);
unmount(0, buf);
psmap[f->mid] = 0;
}
if(f->f) {
freefile(f->f);
f->f = nil;
}
if(f->dir){
free(f->dir);
f->dir = nil;
}
*l = f->next;
f->next = fidfree;
fidfree = f;
return 1;
}
l = &f->next;
}
return 0;
}
Fid *
newfid(int nr)
{
Fid *new, **l;
int i;
l = &fidhash(nr);
for(new = *l; new; new = new->next)
if(new->nr == nr)
return 0;
if(fidfree == 0) {
fidfree = emallocz(sizeof(Fid) * Fidchunk);
for(i = 0; i < Fidchunk-1; i++)
fidfree[i].next = &fidfree[i+1];
fidfree[Fidchunk-1].next = 0;
}
new = fidfree;
fidfree = new->next;
memset(new, 0, sizeof(Fid));
new->next = *l;
*l = new;
new->nr = nr;
new->fid = -1;
new->mid = 0;
return new;
}
Fsrpc *
getsbuf(void)
{
static int ap;
int look, rounds;
Fsrpc *wb;
int small_instead_of_fast = 1;
if(small_instead_of_fast)
ap = 0; /* so we always start looking at the beginning and reuse buffers */
for(rounds = 0; rounds < 10; rounds++) {
for(look = 0; look < Nr_workbufs; look++) {
if(++ap == Nr_workbufs)
ap = 0;
if(Workq[ap].busy == 0)
break;
}
if(look == Nr_workbufs){
sleep(10 * rounds);
continue;
}
wb = &Workq[ap];
wb->pid = 0;
wb->canint = 0;
wb->flushtag = NOTAG;
wb->busy = 1;
if(wb->buf == nil) /* allocate buffers dynamically to keep size down */
wb->buf = emallocz(messagesize);
return wb;
}
fatal("No more work buffers");
return nil;
}
void
freefile(File *f)
{
File *parent, *child;
Loop:
f->ref--;
if(f->ref > 0)
return;
freecnt++;
if(f->ref < 0) abort();
DEBUG(DFD, "free %s\n", f->name);
/* delete from parent */
parent = f->parent;
if(parent->child == f)
parent->child = f->childlist;
else{
for(child=parent->child; child->childlist!=f; child=child->childlist)
if(child->childlist == nil)
fatal("bad child list");
child->childlist = f->childlist;
}
freeqid(f->qidt);
free(f->name);
f->name = nil;
free(f);
f = parent;
if(f != nil)
goto Loop;
}
File *
file(File *parent, char *name)
{
Dir *dir;
char *path;
File *f;
DEBUG(DFD, "\tfile: 0x%p %s name %s\n", parent, parent->name, name);
path = makepath(parent, name);
if(patternfile != nil && excludefile(path)){
free(path);
return nil;
}
dir = dirstat(path);
free(path);
if(dir == nil)
return nil;
for(f = parent->child; f; f = f->childlist)
if(strcmp(name, f->name) == 0)
break;
if(f == nil){
f = emallocz(sizeof(File));
f->name = estrdup(name);
f->parent = parent;
f->childlist = parent->child;
parent->child = f;
parent->ref++;
f->ref = 0;
filecnt++;
}
f->ref++;
f->qid.type = dir->qid.type;
f->qid.vers = dir->qid.vers;
f->qidt = uniqueqid(dir);
f->qid.path = f->qidt->uniqpath;
f->inval = 0;
free(dir);
return f;
}
void
initroot(void)
{
Dir *dir;
root = emallocz(sizeof(File));
root->name = estrdup(".");
dir = dirstat(root->name);
if(dir == nil)
fatal("root stat");
root->ref = 1;
root->qid.vers = dir->qid.vers;
root->qidt = uniqueqid(dir);
root->qid.path = root->qidt->uniqpath;
root->qid.type = QTDIR;
free(dir);
psmpt = emallocz(sizeof(File));
psmpt->name = estrdup("/");
dir = dirstat(psmpt->name);
if(dir == nil)
return;
psmpt->ref = 1;
psmpt->qid.vers = dir->qid.vers;
psmpt->qidt = uniqueqid(dir);
psmpt->qid.path = psmpt->qidt->uniqpath;
free(dir);
psmpt = file(psmpt, "mnt");
if(psmpt == 0)
return;
psmpt = file(psmpt, "exportfs");
}
char*
makepath(File *p, char *name)
{
int i, n;
char *c, *s, *path, *seg[256];
seg[0] = name;
n = strlen(name)+2;
for(i = 1; i < 256 && p; i++, p = p->parent){
seg[i] = p->name;
n += strlen(p->name)+1;
}
path = malloc(n);
if(path == nil)
fatal("out of memory");
s = path;
while(i--) {
for(c = seg[i]; *c; c++)
*s++ = *c;
*s++ = '/';
}
while(s[-1] == '/')
s--;
*s = '\0';
return path;
}
int
qidhash(vlong path)
{
int h, n;
h = 0;
for(n=0; n<64; n+=Nqidbits){
h ^= path;
path >>= Nqidbits;
}
return h & (Nqidtab-1);
}
void
freeqid(Qidtab *q)
{
ulong h;
Qidtab *l;
q->ref--;
if(q->ref > 0)
return;
qfreecnt++;
h = qidhash(q->path);
if(qidtab[h] == q)
qidtab[h] = q->next;
else{
for(l=qidtab[h]; l->next!=q; l=l->next)
if(l->next == nil)
fatal("bad qid list");
l->next = q->next;
}
free(q);
}
Qidtab*
qidlookup(Dir *d)
{
ulong h;
Qidtab *q;
h = qidhash(d->qid.path);
for(q=qidtab[h]; q!=nil; q=q->next)
if(q->type==d->type && q->dev==d->dev && q->path==d->qid.path)
return q;
return nil;
}
int
qidexists(vlong path)
{
int h;
Qidtab *q;
for(h=0; h<Nqidtab; h++)
for(q=qidtab[h]; q!=nil; q=q->next)
if(q->uniqpath == path)
return 1;
return 0;
}
Qidtab*
uniqueqid(Dir *d)
{
ulong h;
vlong path;
Qidtab *q;
q = qidlookup(d);
if(q != nil){
q->ref++;
return q;
}
path = d->qid.path;
while(qidexists(path)){
DEBUG(DFD, "collision on %s\n", d->name);
/* collision: find a new one */
ncollision++;
path &= QIDPATH;
++newqid;
if(newqid >= (1<<16)){
DEBUG(DFD, "collision wraparound\n");
newqid = 1;
}
path |= newqid<<48;
DEBUG(DFD, "assign qid %.16llux\n", path);
}
q = mallocz(sizeof(Qidtab), 1);
if(q == nil)
fatal("no memory for qid table");
qidcnt++;
q->ref = 1;
q->type = d->type;
q->dev = d->dev;
q->path = d->qid.path;
q->uniqpath = path;
h = qidhash(d->qid.path);
q->next = qidtab[h];
qidtab[h] = q;
return q;
}
void
fatal(char *s, ...)
{
char buf[ERRMAX];
va_list arg;
Proc *m;
if (s) {
va_start(arg, s);
vsnprint(buf, ERRMAX, s, arg);
va_end(arg);
}
/* Clear away the slave children */
for(m = Proclist; m; m = m->next)
postnote(PNPROC, m->pid, "kill");
DEBUG(DFD, "%s\n", buf);
if (s)
sysfatal("%s", buf); /* caution: buf could contain '%' */
else
exits(nil);
}
void*
emallocz(uint n)
{
void *p;
p = mallocz(n, 1);
if(p == nil)
fatal(Enomem);
return p;
}
char*
estrdup(char *s)
{
char *t;
t = strdup(s);
if(t == nil)
fatal(Enomem);
return t;
}
/* Network on fd1, mount driver on fd0 */
int
filter(int fd, char *cmd)
{
int p[2], lfd, len, nb, argc;
char newport[128], buf[128], devdir[40], *s, *file, *argv[16];
/* Get a free port and post it to the client. */
if (announce(anstring, devdir) < 0)
sysfatal("filter: Cannot announce %s: %r", anstring);
snprint(buf, sizeof(buf), "%s/local", devdir);
buf[sizeof buf - 1] = '\0';
if ((lfd = open(buf, OREAD)) < 0)
sysfatal("filter: Cannot open %s: %r", buf);
if ((len = read(lfd, newport, sizeof newport - 1)) < 0)
sysfatal("filter: Cannot read %s: %r", buf);
close(lfd);
newport[len] = '\0';
if ((s = strchr(newport, '\n')) != nil)
*s = '\0';
if ((nb = write(fd, newport, len)) < 0)
sysfatal("getport; cannot write port; %r");
assert(nb == len);
argc = tokenize(cmd, argv, nelem(argv)-2);
if (argc == 0)
sysfatal("filter: empty command");
argv[argc++] = buf;
argv[argc] = nil;
file = argv[0];
if (s = strrchr(argv[0], '/'))
argv[0] = s+1;
if(pipe(p) < 0)
fatal("pipe");
switch(rfork(RFNOWAIT|RFPROC|RFFDG)) {
case -1:
fatal("rfork record module");
case 0:
if (dup(p[0], 1) < 0)
fatal("filter: Cannot dup to 1; %r\n");
if (dup(p[0], 0) < 0)
fatal("filter: Cannot dup to 0; %r\n");
close(p[0]);
close(p[1]);
exec(file, argv);
fatal("exec record module");
default:
close(fd);
close(p[0]);
}
return p[1];
}
static void
mksecret(char *t, uchar *f)
{
sprint(t, "%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux",
f[0], f[1], f[2], f[3], f[4], f[5], f[6], f[7], f[8], f[9]);
}