ref: a557c515c8c9c01fdb4f6cc850665be05accd84c
dir: /sys/src/cmd/ip/tftpfs.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <auth.h>
#include <fcall.h>
#include <9p.h>
#include <ip.h>
enum {
Qdata = 1,
Tftp_READ = 1,
Tftp_WRITE = 2,
Tftp_DATA = 3,
Tftp_ACK = 4,
Tftp_ERROR = 5,
Tftp_OACK = 6,
TftpPort = 69,
Segsize = 512,
Maxpath = 2+2+Segsize-8,
};
typedef struct Tfile Tfile;
struct Tfile
{
int id;
uchar addr[IPaddrlen];
char path[Maxpath];
Channel *c;
Tfile *next;
Ref;
};
char net[Maxpath];
uchar ipaddr[IPaddrlen];
static ulong time0;
Tfile *files;
static Tfile*
tfileget(uchar *addr, char *path)
{
Tfile *f;
static int id;
for(f = files; f; f = f->next){
if(memcmp(addr, f->addr, IPaddrlen) == 0 && strcmp(path, f->path) == 0){
incref(f);
return f;
}
}
f = emalloc9p(sizeof *f);
memset(f, 0, sizeof(*f));
ipmove(f->addr, addr);
strncpy(f->path, path, Maxpath-1);
f->ref = 1;
f->id = id++;
f->next = files;
files = f;
return f;
}
static void
tfileput(Tfile *f)
{
Channel *c;
Tfile **pp;
if(f==nil || decref(f))
return;
if(c = f->c){
f->c = nil;
sendp(c, nil);
}
for(pp = &files; *pp; pp = &(*pp)->next){
if(*pp == f){
*pp = f->next;
break;
}
}
free(f);
}
static char*
basename(char *p)
{
char *b;
for(b = p; *p; p++)
if(*p == '/')
b = p+1;
return b;
}
static void
tfilestat(Req *r, char *path, vlong length)
{
memset(&r->d, 0, sizeof(r->d));
r->d.uid = estrdup9p("tftp");
r->d.gid = estrdup9p("tftp");
r->d.name = estrdup9p(basename(path));
r->d.atime = r->d.mtime = time0;
r->d.length = length;
r->d.qid.path = r->fid->qid.path;
if(r->fid->qid.path & Qdata){
r->d.qid.type = 0;
r->d.mode = 0555;
} else {
r->d.qid.type = QTDIR;
r->d.mode = DMDIR|0555;
}
respond(r, nil);
}
static void
catch(void *, char *msg)
{
if(strstr(msg, "alarm"))
noted(NCONT);
noted(NDFLT);
}
static int
filereq(uchar *buf, char *path)
{
uchar *p;
int n;
hnputs(buf, Tftp_READ);
p = buf+2;
n = strlen(path);
/* hack: remove the trailing dot */
if(path[n-1] == '.')
n--;
memcpy(p, path, n);
p += n;
*p++ = 0;
memcpy(p, "octet", 6);
p += 6;
return p - buf;
}
static void
download(void *aux)
{
int fd, cfd, last, block, seq, n, ndata;
char *err, adir[40], buf[256];
uchar *data;
Channel *c;
Tfile *f;
Req *r;
struct {
Udphdr;
uchar buf[2+2+Segsize+1];
} msg;
c = nil;
r = nil;
fd = cfd = -1;
err = nil;
data = nil;
ndata = 0;
if((f = aux) == nil)
goto out;
if((c = f->c) == nil)
goto out;
threadsetname("%s", f->path);
snprint(buf, sizeof(buf), "%s/udp!*!0", net);
if((cfd = announce(buf, adir)) < 0){
err = "announce: %r";
goto out;
}
if(write(cfd, "headers", 7) < 0){
err = "write ctl: %r";
goto out;
}
strcat(adir, "/data");
if((fd = open(adir, ORDWR)) < 0){
err = "open: %r";
goto out;
}
n = filereq(msg.buf, f->path);
ipmove(msg.raddr, f->addr);
hnputs(msg.rport, TftpPort);
if(write(fd, &msg, sizeof(Udphdr) + n) < 0){
err = "send read request: %r";
goto out;
}
notify(catch);
seq = 1;
last = 0;
while(!last){
alarm(5000);
if((n = read(fd, &msg, sizeof(Udphdr) + sizeof(msg.buf)-1)) < 0){
err = "receive response: %r";
goto out;
}
alarm(0);
n -= sizeof(Udphdr);
msg.buf[n] = 0;
switch(nhgets(msg.buf)){
case Tftp_ERROR:
werrstr("%s", (char*)msg.buf+4);
err = "%r";
goto out;
case Tftp_DATA:
if(n < 4)
continue;
block = nhgets(msg.buf+2);
if(block > seq)
continue;
hnputs(msg.buf, Tftp_ACK);
if(write(fd, &msg, sizeof(Udphdr) + 4) < 0){
err = "send acknowledge: %r";
goto out;
}
if(block < seq)
continue;
seq = block+1;
n -= 4;
if(n < Segsize)
last = 1;
data = erealloc9p(data, ndata + n);
memcpy(data + ndata, msg.buf+4, n);
ndata += n;
rloop: /* hanlde read request while downloading */
if((r != nil) && (r->ifcall.type == Tread) && (r->ifcall.offset < ndata)){
readbuf(r, data, ndata);
respond(r, nil);
r = nil;
}
if((r == nil) && (nbrecv(c, &r) == 1)){
if(r == nil){
chanfree(c);
c = nil;
goto out;
}
goto rloop;
}
break;
}
}
out:
alarm(0);
if(cfd >= 0)
close(cfd);
if(fd >= 0)
close(fd);
if(c){
while((r != nil) || (r = recvp(c))){
if(err){
snprint(buf, sizeof(buf), err);
respond(r, buf);
} else {
switch(r->ifcall.type){
case Tread:
readbuf(r, data, ndata);
respond(r, nil);
break;
case Tstat:
tfilestat(r, f->path, ndata);
break;
default:
respond(r, "bug in fs");
}
}
r = nil;
}
chanfree(c);
}
free(data);
}
static void
fsattach(Req *r)
{
Tfile *f;
if(r->ifcall.aname && r->ifcall.aname[0]){
uchar addr[IPaddrlen];
if(parseip(addr, r->ifcall.aname) == -1){
respond(r, "bad ip specified");
return;
}
f = tfileget(addr, "/");
} else {
if(ipcmp(ipaddr, IPnoaddr) == 0){
respond(r, "no ipaddr specified");
return;
}
f = tfileget(ipaddr, "/");
}
r->fid->aux = f;
r->fid->qid.type = QTDIR;
r->fid->qid.path = f->id<<1;
r->fid->qid.vers = 0;
r->ofcall.qid = r->fid->qid;
respond(r, nil);
}
static char*
fswalk1(Fid *fid, char *name, Qid *qid)
{
Tfile *f;
char *t;
f = fid->aux;
t = smprint("%s/%s", f->path, name);
f = tfileget(f->addr, cleanname(t));
free(t);
tfileput(fid->aux); fid->aux = f;
fid->qid.type = QTDIR;
fid->qid.path = f->id<<1;
/* hack:
* a dot in the path means the path element is not
* a directory. to force download of files containing
* no dot, a trailing dot can be appended that will
* be stripped out in the tftp read request.
*/
if(strchr(f->path, '.') != nil){
fid->qid.type = 0;
fid->qid.path |= Qdata;
}
if(qid)
*qid = fid->qid;
return nil;
}
static char*
fsclone(Fid *oldfid, Fid *newfid)
{
Tfile *f;
f = oldfid->aux;
incref(f);
newfid->aux = f;
return nil;
}
static void
fsdestroyfid(Fid *fid)
{
tfileput(fid->aux);
fid->aux = nil;
}
static void
fsopen(Req *r)
{
int m;
m = r->ifcall.mode & 3;
if(m != OREAD && m != OEXEC){
respond(r, "permission denied");
return;
}
respond(r, nil);
}
static void
dispatch(Req *r)
{
Tfile *f;
f = r->fid->aux;
if(f->c == nil){
f->c = chancreate(sizeof(r), 0);
proccreate(download, f, 16*1024);
}
sendp(f->c, r);
}
static void
fsread(Req *r)
{
if(r->fid->qid.path & Qdata){
dispatch(r);
} else {
respond(r, nil);
}
}
static void
fsstat(Req *r)
{
if(r->fid->qid.path & Qdata){
dispatch(r);
} else {
tfilestat(r, ((Tfile*)r->fid->aux)->path, 0);
}
}
Srv fs =
{
.attach= fsattach,
.destroyfid= fsdestroyfid,
.walk1= fswalk1,
.clone= fsclone,
.open= fsopen,
.read= fsread,
.stat= fsstat,
};
void
usage(void)
{
fprint(2, "usage: tftpfs [-D] [-s srvname] [-m mtpt] [-x net] [ipaddr]\n");
threadexitsall("usage");
}
void
threadmain(int argc, char **argv)
{
char *srvname = nil;
char *mtpt = "/n/tftp";
time0 = time(0);
strcpy(net, "/net");
ipmove(ipaddr, IPnoaddr);
ARGBEGIN{
case 'D':
chatty9p++;
break;
case 's':
srvname = EARGF(usage());
mtpt = nil;
break;
case 'm':
mtpt = EARGF(usage());
break;
case 'x':
setnetmtpt(net, sizeof net, EARGF(usage()));
break;
default:
usage();
}ARGEND;
switch(argc){
case 0:
break;
case 1:
if(parseip(ipaddr, *argv) == -1)
usage();
break;
default:
usage();
}
if(srvname==nil && mtpt==nil)
usage();
threadpostmountsrv(&fs, srvname, mtpt, MREPL|MCREATE);
}