#include <fcall.h>

#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
#include <libsec.h>

int readonly;
int debug;
char *root = ".";
#define dprint(...) if(debug) fprint(2, __VA_ARGS__)
#pragma varargck type "Σ" int

enum {
MAXPACK = 34000,
MAXWRITE = 32768,
MAXATTRIB = 64,
VERSION = 3,
MAXREQID = 32,
HASH = 64
};

enum {
SSH_FXP_INIT = 1,
SSH_FXP_VERSION = 2,
SSH_FXP_OPEN = 3,
SSH_FXP_CLOSE = 4,
SSH_FXP_READ = 5,
SSH_FXP_WRITE = 6,
SSH_FXP_LSTAT = 7,
SSH_FXP_FSTAT = 8,
SSH_FXP_SETSTAT = 9,
SSH_FXP_FSETSTAT = 10,
SSH_FXP_OPENDIR = 11,
SSH_FXP_READDIR = 12,
SSH_FXP_REMOVE = 13,
SSH_FXP_MKDIR = 14,
SSH_FXP_RMDIR = 15,
SSH_FXP_REALPATH = 16,
SSH_FXP_STAT = 17,
SSH_FXP_RENAME = 18,
SSH_FXP_READLINK = 19,
SSH_FXP_SYMLINK = 20,
SSH_FXP_STATUS = 101,
SSH_FXP_HANDLE = 102,
SSH_FXP_DATA = 103,
SSH_FXP_NAME = 104,
SSH_FXP_ATTRS = 105,
SSH_FXP_EXTENDED = 200,
SSH_FXP_EXTENDED_REPLY = 201,

SSH_FXF_READ = 0x00000001,
SSH_FXF_WRITE = 0x00000002,
SSH_FXF_APPEND = 0x00000004,
SSH_FXF_CREAT = 0x00000008,
SSH_FXF_TRUNC = 0x00000010,
SSH_FXF_EXCL = 0x00000020,
SSH_FILEXFER_ATTR_SIZE = 0x00000001,
SSH_FILEXFER_ATTR_UIDGID = 0x00000002,
SSH_FILEXFER_ATTR_PERMISSIONS = 0x00000004,
SSH_FILEXFER_ATTR_ACMODTIME = 0x00000008,
SSH_FILEXFER_ATTR_EXTENDED = 0x80000000,

SSH_FX_OK = 0,
SSH_FX_EOF = 1,
SSH_FX_NO_SUCH_FILE = 2,
SSH_FX_PERMISSION_DENIED = 3,
SSH_FX_FAILURE = 4,
SSH_FX_BAD_MESSAGE = 5,
SSH_FX_NO_CONNECTION = 6,
SSH_FX_CONNECTION_LOST = 7,
SSH_FX_OP_UNSUPPORTED = 8,
};

char *errors[] = {
[SSH_FX_OK] "success",
[SSH_FX_EOF] "end of file",
[SSH_FX_NO_SUCH_FILE] "file does not exist",
[SSH_FX_PERMISSION_DENIED] "permission denied",
[SSH_FX_FAILURE] "failure",
[SSH_FX_BAD_MESSAGE] "bad message",
[SSH_FX_NO_CONNECTION] "no connection",
[SSH_FX_CONNECTION_LOST] "connection lost",
[SSH_FX_OP_UNSUPPORTED] "unsupported operation",
};

typedef struct SFid SFid;
typedef struct SReq SReq;
typedef struct IDEnt IDEnt;

struct SFid {
RWLock;
char *fn;
uchar *hand;
int handn;
Qid qid;
int dirreads;
Dir *dirent;
int ndirent, dirpos;
uchar direof;
};

struct SReq {
Req *req;
SFid *closefid;
SReq *next;
};

struct IDEnt {
char *name;
int id;
IDEnt *next;
};
IDEnt *uidtab[HASH], *gidtab[HASH];

int rdfd, wrfd;
SReq *sreqrd[MAXREQID];
QLock sreqidlock;
Rendez sreqidrend = {.l = &sreqidlock};

SReq *sreqwr, **sreqlast = &sreqwr;
QLock sreqwrlock;
Rendez writerend = {.l = &sreqwrlock};

#define PUT4(p, u) (p)[0] = (u)>>24, (p)[1] = (u)>>16, (p)[2] = (u)>>8, (p)[3] = (u)
#define GET4(p) ((u32int)(p)[3] | (u32int)(p)[2]<<8 | (u32int)(p)[1]<<16 | (u32int)(p)[0]<<24)

int
fxpfmt(Fmt *f)
{
int n;

n = va_arg(f->args, int);
switch(n){
case SSH_FXP_INIT: fmtstrcpy(f, "SSH_FXP_INIT"); break;
case SSH_FXP_VERSION: fmtstrcpy(f, "SSH_FXP_VERSION"); break;
case SSH_FXP_OPEN: fmtstrcpy(f, "SSH_FXP_OPEN"); break;
case SSH_FXP_CLOSE: fmtstrcpy(f, "SSH_FXP_CLOSE"); break;
case SSH_FXP_READ: fmtstrcpy(f, "SSH_FXP_READ"); break;
case SSH_FXP_WRITE: fmtstrcpy(f, "SSH_FXP_WRITE"); break;
case SSH_FXP_LSTAT: fmtstrcpy(f, "SSH_FXP_LSTAT"); break;
case SSH_FXP_FSTAT: fmtstrcpy(f, "SSH_FXP_FSTAT"); break;
case SSH_FXP_SETSTAT: fmtstrcpy(f, "SSH_FXP_SETSTAT"); break;
case SSH_FXP_FSETSTAT: fmtstrcpy(f, "SSH_FXP_FSETSTAT"); break;
case SSH_FXP_OPENDIR: fmtstrcpy(f, "SSH_FXP_OPENDIR"); break;
case SSH_FXP_READDIR: fmtstrcpy(f, "SSH_FXP_READDIR"); break;
case SSH_FXP_REMOVE: fmtstrcpy(f, "SSH_FXP_REMOVE"); break;
case SSH_FXP_MKDIR: fmtstrcpy(f, "SSH_FXP_MKDIR"); break;
case SSH_FXP_RMDIR: fmtstrcpy(f, "SSH_FXP_RMDIR"); break;
case SSH_FXP_REALPATH: fmtstrcpy(f, "SSH_FXP_REALPATH"); break;
case SSH_FXP_STAT: fmtstrcpy(f, "SSH_FXP_STAT"); break;
case SSH_FXP_RENAME: fmtstrcpy(f, "SSH_FXP_RENAME"); break;
case SSH_FXP_READLINK: fmtstrcpy(f, "SSH_FXP_READLINK"); break;
case SSH_FXP_SYMLINK: fmtstrcpy(f, "SSH_FXP_SYMLINK"); break;
case SSH_FXP_STATUS: fmtstrcpy(f, "SSH_FXP_STATUS"); break;
case SSH_FXP_HANDLE: fmtstrcpy(f, "SSH_FXP_HANDLE"); break;
case SSH_FXP_DATA: fmtstrcpy(f, "SSH_FXP_DATA"); break;
case SSH_FXP_NAME: fmtstrcpy(f, "SSH_FXP_NAME"); break;
case SSH_FXP_ATTRS: fmtstrcpy(f, "SSH_FXP_ATTRS"); break;
case SSH_FXP_EXTENDED: fmtstrcpy(f, "SSH_FXP_EXTENDED"); break;
case SSH_FXP_EXTENDED_REPLY: fmtstrcpy(f, "SSH_FXP_EXTENDED_REPLY");
default: fmtprint(f, "%d", n);
}
return 0;
}

char *
idlookup(IDEnt **tab, int id)
{
IDEnt *p;

for(p = tab[(ulong)id % HASH]; p != nil; p = p->next)
if(p->id == id)
return estrdup9p(p->name);
return smprint("%d", id);
}

int
namelookup(IDEnt **tab, char *name)
{
IDEnt *p;
int i;
char *q;

for(i = 0; i < HASH; i++)
for(p = tab[i]; p != nil; p = p->next)
if(strcmp(p->name, name) == 0)
return p->id;
i = strtol(name, &q, 10);
if(*q == 0) return i;
werrstr("unknown %s '%s'", tab == uidtab ? "user" : "group", name);
return -1;
}

int
allocsreqid(SReq *r)
{
int i;

qlock(&sreqidlock);
for(;;){
for(i = 0; i < MAXREQID; i++)
if(sreqrd[i] == nil){
sreqrd[i] = r;
goto out;
}
rsleep(&sreqidrend);
}
out:
qunlock(&sreqidlock);
return i;
}

int
vpack(uchar *p, int n, char *fmt, va_list a)
{
uchar *p0 = p, *e = p+n;
SReq *sr = nil;
u32int u;
u64int v;
void *s;
int c;

for(;;){
switch(c = *fmt++){
case '\0':
if(sr != nil){
u = allocsreqid(sr);
PUT4(p0+1, u);
}
return p - p0;
case '_':
if(++p > e) goto err;
break;
case '.':
*va_arg(a, void**) = p;
break;
case 'b':
if(p >= e) goto err;
*p++ = va_arg(a, int);
break;
case '[':
case 's':
s = va_arg(a, void*);
u = va_arg(a, int);
if(c == 's'){
if(p+4 > e) goto err;
PUT4(p, u), p += 4;
}
if(u > e-p) goto err;
memmove(p, s, u);
p += u;
break;
case 'q':
p += 4;
if(p != p0+5 || p > e) goto err;
sr = va_arg(a, SReq*);
break;
case 'u':
u = va_arg(a, int);
if(p+4 > e) goto err;
PUT4(p, u), p += 4;
break;
case 'v':
v = va_arg(a, vlong);
if(p+8 > e) goto err;
u = v>>32; PUT4(p, u), p += 4;
u = v; PUT4(p, u), p += 4;
break;
}
}
err:
return -1;
}

int
vunpack(uchar *p, int n, char *fmt, va_list a)
{
uchar *p0 = p, *e = p+n;
u32int u;
u64int v;
void *s;

for(;;){
switch(*fmt++){
case '\0':
return p - p0;
case '_':
if(++p > e) goto err;
break;
case '.':
*va_arg(a, void**) = p;
break;
case 'b':
if(p >= e) goto err;
*va_arg(a, int*) = *p++;
break;
case 's':
if(p+4 > e) goto err;
u = GET4(p), p += 4;
if(u > e-p) goto err;
*va_arg(a, void**) = p;
*va_arg(a, int*) = u;
p += u;
break;
case '[':
s = va_arg(a, void*);
u = va_arg(a, int);
if(u > e-p) goto err;
memmove(s, p, u);
p += u;
break;
case 'u':
if(p+4 > e) goto err;
u = GET4(p);
*va_arg(a, int*) = u;
p += 4;
break;
case 'v':
if(p+8 > e) goto err;
v = (u64int)GET4(p) << 32;
v |= (u32int)GET4(p+4);
*va_arg(a, vlong*) = v;
p += 8;
break;
}
}
err:
return -1;
}

int
pack(uchar *p, int n, char *fmt, ...)
{
va_list a;
va_start(a, fmt);
n = vpack(p, n, fmt, a);
va_end(a);
return n;
}
int
unpack(uchar *p, int n, char *fmt, ...)
{
va_list a;
va_start(a, fmt);
n = vunpack(p, n, fmt, a);
va_end(a);
return n;
}

void
sendpkt(char *fmt, ...)
{
static uchar buf[MAXPACK];
int n;
va_list a;

va_start(a, fmt);
n = vpack(buf+4, sizeof(buf)-4, fmt, a);
va_end(a);
if(n < 0) {
sysfatal("sendpkt: message too big");
return;
}
PUT4(buf, n);
n += 4;

dprint("SFTP --> %Σ\n", (int)buf[4]);
if(write(wrfd, buf, n) != n)
sysfatal("write: %r");
}

static uchar rxpkt[MAXPACK];
static int rxlen;

int
recvpkt(void)
{
static uchar rxbuf[MAXPACK];
static int rxfill;
int rc;

while(rxfill < 4 || rxfill < (rxlen = GET4(rxbuf) + 4) && rxlen <= MAXPACK){
rc = read(rdfd, rxbuf + rxfill, MAXPACK - rxfill);
if(rc < 0) sysfatal("read: %r");
if(rc == 0) sysfatal("read: eof");
rxfill += rc;
}
if(rxlen > MAXPACK) sysfatal("received garbage");
memmove(rxpkt, rxbuf + 4, rxlen - 4);
memmove(rxbuf, rxbuf + rxlen, rxfill - rxlen);
rxfill -= rxlen;
rxlen -= 4;
dprint("SFTP <-- %Σ\n", (int)rxpkt[0]);
return rxpkt[0];
}

void
freedir1(Dir *d)
{
free(d->name);
free(d->uid);
free(d->gid);
free(d->muid);
}

void
freedir(SFid *s)
{
int i;

for(i = 0; i < s->ndirent; i++)
freedir1(&s->dirent[i]);
free(s->dirent);
s->dirent = nil;
s->ndirent = 0;
s->dirpos = 0;
}

void
putsfid(SFid *s)
{
if(s == nil) return;

wlock(s);
wunlock(s);

free(s->fn);
free(s->hand);
freedir(s);
free(s);
}

void
putsreq(SReq *s)
{
free(s);
}

void
submitsreq(SReq *s)
{
qlock(&sreqwrlock);
*sreqlast = s;
sreqlast = &s->next;
rwakeup(&writerend);
qunlock(&sreqwrlock);
}

void
submitreq(Req *r)
{
SReq *s;

s = emalloc9p(sizeof(SReq));
s->req = r;
submitsreq(s);
}

char *
pathcat(char *p, char *c)
{
return cleanname(smprint("%s/%s", p, c));
}

char *
parentdir(char *p)
{
return pathcat(p, "..");
}

char *
finalelem(char *p)
{
char *q;

q = strrchr(p, '/');
if(q == nil) return estrdup9p(p);
return estrdup9p(q+1);
}

u64int
qidcalc(char *c)
{
uchar dig[SHA1dlen];

sha1((uchar *) c, strlen(c), dig, nil);
return dig[0] | dig[1] << 8 | dig[2] << 16 | dig[3] << 24 | (uvlong)dig[4] << 32 | (uvlong)dig[5] << 40 | (uvlong)dig[6] << 48 | (uvlong)dig[7] << 56;
}

void
walkprocess(Req *r, char *e)
{
char *p;
SFid *sf;

sf = r->newfid->aux;
if(e != nil){
r->ofcall.nwqid--;
if(r->ofcall.nwqid == 0){
respond(r, e);
return;
}
p = r->aux;
r->aux = parentdir(p);
free(p);
submitreq(r);
}else{
assert(r->ofcall.nwqid > 0);
wlock(sf);
free(sf->fn);
sf->fn = r->aux;
r->aux = nil;
sf->qid = r->ofcall.wqid[r->ofcall.nwqid - 1];
wunlock(sf);
respond(r, nil);
}
}

int
attrib2dir(uchar *p0, uchar *ep, Dir *d)
{
uchar *p;
int i, rc, extn, extvn;
u32int flags, uid, gid, perm, next;
uchar *exts, *extvs;

p = p0;
if(p + 4 > ep) return -1;
flags = GET4(p), p += 4;
if((flags & SSH_FILEXFER_ATTR_SIZE) != 0){
rc = unpack(p, ep - p, "v", &d->length); if(rc < 0) return -1; p += rc;
}
if((flags & SSH_FILEXFER_ATTR_UIDGID) != 0){
rc = unpack(p, ep - p, "uu", &uid, &gid); if(rc < 0) return -1; p += rc;
d->uid = idlookup(uidtab, uid);
d->gid = idlookup(gidtab, gid);
}else{
d->uid = estrdup9p("sshfs");
d->gid = estrdup9p("sshfs");
}
d->muid = estrdup9p(d->uid);
if((flags & SSH_FILEXFER_ATTR_PERMISSIONS) != 0){
rc = unpack(p, ep - p, "u", &perm); if(rc < 0) return -1; p += rc;
d->mode = perm & 0777;
if((perm & 0170000) == 0040000) d->mode |= DMDIR;
}
d->qid.type = d->mode >> 24;
if((flags & SSH_FILEXFER_ATTR_ACMODTIME) != 0){
rc = unpack(p, ep - p, "uu", &d->atime, &d->mtime); if(rc < 0) return -1; p += rc;
d->qid.vers = d->mtime;
}
if((flags & SSH_FILEXFER_ATTR_EXTENDED) != 0){
rc = unpack(p, ep - p, "u", &next); if(rc < 0) return -1; p += rc;
for(i = 0; i < next; i++){
rc = unpack(p, ep - p, "ss", &exts, &extn, &extvs, &extvn); if(rc < 0) return -1; p += rc;
exts[extn] = extvs[extvn] = 0;
}
}
return p - p0;
}

int
dir2attrib(Dir *d, uchar **rp)
{
int rc;
uchar *r, *p, *e;
u32int fl;
int uid, gid;

werrstr("phase error");
*rp = r = emalloc9p(MAXATTRIB);
e = r + MAXATTRIB;
fl = 0;
p = r + 4;
if(d->length != (uvlong)-1){
fl |= SSH_FILEXFER_ATTR_SIZE;
rc = pack(p, e - p, "v", d->length); if(rc < 0) return -1; p += rc;
}
if(d->uid != nil && *d->uid != 0 || d->gid != nil && *d->gid != 0){
/* FIXME: sending -1 for "don't change" works with openssh, but violates the spec */
if(d->uid != nil && *d->uid != 0){
uid = namelookup(uidtab, d->uid);
if(uid == -1)
return -1;
}else
uid = -1;
if(d->gid != nil && *d->gid != 0){
gid = namelookup(gidtab, d->gid);
if(gid == -1)
return -1;
}else
gid = -1;
fl |= SSH_FILEXFER_ATTR_UIDGID;
rc = pack(p, e - p, "uu", uid, gid); if(rc < 0) return -1; p += rc;
}
if(d->mode != (ulong)-1){
fl |= SSH_FILEXFER_ATTR_PERMISSIONS;
rc = pack(p, e - p, "u", d->mode); if(rc < 0) return -1; p += rc;
}
if(d->atime != (ulong)-1 || d->mtime != (ulong)-1){
/* FIXME: see above */
fl |= SSH_FILEXFER_ATTR_ACMODTIME;
rc = pack(p, e - p, "uu", d->atime, d->mtime); if(rc < 0) return -1; p += rc;
}
PUT4(r, fl);
return p - r;
}

int
attrfixupqid(Qid *qid)
{
u32int flags;
uchar *p;

if(unpack(rxpkt, rxlen, "_____u", &flags) < 0) return -1;
p = rxpkt + 9;
if(flags & SSH_FILEXFER_ATTR_SIZE) p += 8;
if(flags & SSH_FILEXFER_ATTR_UIDGID) p += 8;
if(flags & SSH_FILEXFER_ATTR_PERMISSIONS){
if(p + 4 > rxpkt + rxlen) return -1;
if((GET4(p) & 0170000) != 0040000) qid->type = 0;
else qid->type = QTDIR;
p += 4;
}
if(flags & SSH_FILEXFER_ATTR_ACMODTIME){
if(p + 8 > rxpkt + rxlen) return -1;
p += 4;
qid->vers = GET4(p); /* mtime for qid.vers */
}
return 0;
}

int
parsedir(SFid *sf)
{
int i, rc;
Dir *d;
u32int c;
uchar *p, *ep;
char *fn, *ln;
int fns, lns;
char *s;

if(unpack(rxpkt, rxlen, "_____u", &c) < 0) return -1;
wlock(sf);
freedir(sf);
sf->dirent = emalloc9p(c * sizeof(Dir));
d = sf->dirent;
p = rxpkt + 9;
ep = rxpkt + rxlen;
for(i = 0; i < c; i++){
memset(d, 0, sizeof(Dir));
rc = unpack(p, ep - p, "ss", &fn, &fns, &ln, &lns); if(rc < 0) goto err; p += rc;
rc = attrib2dir(p, ep, d); if(rc < 0) goto err; p += rc;
if(fn[0] == '.' && (fns == 1 || fns == 2 && fn[1] == '.')){
freedir1(d);
continue;
}
d->name = emalloc9p(fns + 1);
memcpy(d->name, fn, fns);
d->name[fns] = 0;
s = pathcat(sf->fn, d->name);
d->qid.path = qidcalc(s);
free(s);
sf->ndirent++;
d++;
}
wunlock(sf);
return 0;
err:
freedir1(d);
wunlock(sf);
return -1;
}

void
readprocess(Req *r)
{
int i;
uchar *p, *ep;
uint rv;
SFid *sf;

sf = r->fid->aux;
wlock(sf);
if(sf->direof){
wunlock(sf);
respond(r, nil);
return;
}
i = sf->dirpos;
p = (uchar*)r->ofcall.data + r->ofcall.count;
ep = (uchar*)r->ofcall.data + r->ifcall.count;
rv = ep - p;
while(p < ep){
if(i >= sf->ndirent)
break;
rv = convD2M(&sf->dirent[i], p, ep-p);
if(rv <= BIT16SZ)
break;
p += rv;
i++;
}
sf->dirpos = i;
if(i >= sf->ndirent)
freedir(sf);
wunlock(sf);
r->ofcall.count = p - (uchar*)r->ofcall.data;
if(rv <= BIT16SZ)
respond(r, nil);
else
submitreq(r);
}

void
sshfsread(Req *r)
{
if((r->fid->qid.type & QTDIR) == 0){
submitreq(r);
return;
}
if(r->ifcall.offset == 0){
SFid *sf = r->fid->aux;
wlock(sf);
freedir(sf);
if(sf->dirreads > 0){
wunlock(sf);
r->aux = (void*)-1;
submitreq(r);
return;
}
wunlock(sf);
}
readprocess(r);
}

void
sshfsattach(Req *r)
{
SFid *sf;

if(r->aux == nil){
sf = emalloc9p(sizeof(SFid));
if(r->ifcall.aname != nil)
switch(*r->ifcall.aname){
case '~':
switch(r->ifcall.aname[1]){
case 0: sf->fn = estrdup9p("."); break;
case '/': sf->fn = estrdup9p(r->ifcall.aname + 2); break;
default:
free(sf);
respond(r, "invalid attach name");
return;
}
break;
case '/':
sf->fn = estrdup9p(r->ifcall.aname);
break;
case 0:
sf->fn = estrdup9p(root);
break;
default:
sf->fn = pathcat(root, r->ifcall.aname);
}
else
sf->fn = estrdup9p(root);
r->fid->aux = sf;
submitreq(r);
}else{
sf = r->fid->aux;
sf->qid = (Qid){qidcalc(sf->fn), 0, QTDIR};
r->ofcall.qid = sf->qid;
r->fid->qid = sf->qid;
respond(r, nil);
}
}

void
sendproc(void *)
{
SReq *r;
SFid *sf;
int x, y;
char *s, *t;

threadsetname("send");

for(;;){
qlock(&sreqwrlock);
while(sreqwr == nil)
rsleep(&writerend);
r = sreqwr;
sreqwr = r->next;
if(sreqwr == nil) sreqlast = &sreqwr;
qunlock(&sreqwrlock);

sf = r->closefid;
if(sf != nil){
rlock(sf);
sendpkt("bqs", SSH_FXP_CLOSE, r, sf->hand, sf->handn);
runlock(sf);
continue;
}
if(r->req == nil)
sysfatal("nil request in queue");

sf = r->req->fid->aux;
switch(r->req->ifcall.type){
case Tattach:
rlock(sf);
sendpkt("bqs", SSH_FXP_STAT, r, sf->fn, strlen(sf->fn));
runlock(sf);
break;
case Twalk:
sendpkt("bqs", SSH_FXP_STAT, r, r->req->aux, strlen(r->req->aux));
break;
case Topen:
if((r->req->ofcall.qid.type & QTDIR) != 0){
rlock(sf);
sendpkt("bqs", SSH_FXP_OPENDIR, r, sf->fn, strlen(sf->fn));
runlock(sf);
}else{
x = r->req->ifcall.mode;
y = 0;
switch(x & 3){
case OREAD: y = SSH_FXF_READ; break;
case OWRITE: y = SSH_FXF_WRITE; break;
case ORDWR: y = SSH_FXF_READ | SSH_FXF_WRITE; break;
}
if(readonly && (y & SSH_FXF_WRITE) != 0){
respond(r->req, "mounted read-only");
putsreq(r);
break;
}
if((x & OTRUNC) != 0)
y |= SSH_FXF_TRUNC;
rlock(sf);
sendpkt("bqsuu", SSH_FXP_OPEN, r, sf->fn, strlen(sf->fn), y, 0);
runlock(sf);
}
break;
case Tcreate:
rlock(sf);
s = pathcat(sf->fn, r->req->ifcall.name);
runlock(sf);
if((r->req->ifcall.perm & DMDIR) != 0){
if(r->req->aux == nil){
r->req->aux = (void*)-1;
sendpkt("bqsuu", SSH_FXP_MKDIR, r, s, strlen(s),
SSH_FILEXFER_ATTR_PERMISSIONS, r->req->ifcall.perm & 0777);
}else{
r->req->aux = (void*)-2;
sendpkt("bqs", SSH_FXP_OPENDIR, r, s, strlen(s));
}
free(s);
break;
}
x = r->req->ifcall.mode;
y = SSH_FXF_CREAT | SSH_FXF_EXCL;
switch(x & 3){
case OREAD: y |= SSH_FXF_READ; break;
case OWRITE: y |= SSH_FXF_WRITE; break;
case ORDWR: y |= SSH_FXF_READ | SSH_FXF_WRITE; break;
}
sendpkt("bqsuuu", SSH_FXP_OPEN, r, s, strlen(s), y,
SSH_FILEXFER_ATTR_PERMISSIONS, r->req->ifcall.perm & 0777);
free(s);
break;
case Tread:
if((r->req->fid->qid.type & QTDIR) != 0){
wlock(sf);
if(r->req->aux == (void*)-1){
sendpkt("bqs", SSH_FXP_CLOSE, r, sf->hand, sf->handn);
free(sf->hand);
sf->hand = nil;
sf->handn = 0;
sf->direof = 0;
sf->dirreads = 0;
}else if(r->req->aux == (void*)-2){
sendpkt("bqs", SSH_FXP_OPENDIR, r, sf->fn, strlen(sf->fn));
}else{
sf->dirreads++;
sendpkt("bqs", SSH_FXP_READDIR, r, sf->hand, sf->handn);
}
wunlock(sf);
}else{
rlock(sf);
sendpkt("bqsvuu", SSH_FXP_READ, r, sf->hand, sf->handn,
r->req->ifcall.offset, r->req->ifcall.count);
runlock(sf);
}
break;
case Twrite:
x = r->req->ifcall.count - r->req->ofcall.count;
if(x >= MAXWRITE) x = MAXWRITE;
r->req->ofcall.offset = x;
rlock(sf);
sendpkt("bqsvs", SSH_FXP_WRITE, r, sf->hand, sf->handn,
r->req->ifcall.offset + r->req->ofcall.count,
r->req->ifcall.data + r->req->ofcall.count,
x);
runlock(sf);
break;
case Tstat:
rlock(sf);
r->req->d.name = finalelem(sf->fn);
r->req->d.qid = sf->qid;
if(sf->handn > 0 && (sf->qid.type & QTDIR) == 0)
sendpkt("bqs", SSH_FXP_FSTAT, r, sf->hand, sf->handn);
else
sendpkt("bqs", SSH_FXP_STAT, r, sf->fn, strlen(sf->fn));
runlock(sf);
break;
case Twstat:
if(r->req->aux == (void*)-1){
rlock(sf);
s = parentdir(sf->fn);
t = pathcat(s, r->req->d.name);
r->req->aux = t;
sendpkt("bqss", SSH_FXP_RENAME, r, sf->fn, strlen(sf->fn), t, strlen(t));
runlock(sf);
free(s);
break;
}
x = dir2attrib(&r->req->d, (uchar **) &s);
if(x < 0){
responderror(r->req);
putsreq(r);
free(s);
break;
}
rlock(sf);
if(sf->handn > 0)
sendpkt("bqs[", SSH_FXP_FSETSTAT, r, sf->hand, sf->handn, s, x);
else
sendpkt("bqs[", SSH_FXP_SETSTAT, r, sf->fn, strlen(sf->fn), s, x);
runlock(sf);
free(s);
break;
case Tremove:
rlock(sf);
if((sf->qid.type & QTDIR) != 0)
sendpkt("bqs", SSH_FXP_RMDIR, r, sf->fn, strlen(sf->fn));
else
sendpkt("bqs", SSH_FXP_REMOVE, r, sf->fn, strlen(sf->fn));
runlock(sf);
break;
default:
fprint(2, "sendproc: unimplemented 9p request %F in queue\n", &r->req->ifcall);
respond(r->req, "phase error");
putsreq(r);
}
}
}

void
recvproc(void *)
{
static char ebuf[256];

SReq *r;
SFid *sf;
int t, id;
u32int code;
char *msg, *lang, *hand, *s;
int msgn, langn, handn;
int okresp;
char *e;

threadsetname("recv");

for(;;){
e = "phase error";
switch(t = recvpkt()){
case SSH_FXP_STATUS:
case SSH_FXP_HANDLE:
case SSH_FXP_DATA:
case SSH_FXP_NAME:
case SSH_FXP_ATTRS:
break;
default:
fprint(2, "sshfs: received unexpected packet of type %Σ\n", t);
continue;
}
id = GET4(rxpkt + 1);
if(id >= MAXREQID){
fprint(2, "sshfs: received %Σ response with id out of range, %d > %d\n", t, id, MAXREQID);
continue;
}
qlock(&sreqidlock);
r = sreqrd[id];
if(r != nil){
sreqrd[id] = nil;
rwakeup(&sreqidrend);
}
qunlock(&sreqidlock);
if(r == nil){
fprint(2, "sshfs: received %Σ response to non-existent request (req id = %d)\n", t, id);
continue;
}
if(r->closefid != nil){
putsfid(r->closefid);
putsreq(r);
continue;
}
if(r->req == nil)
sysfatal("recvproc: r->req == nil");

sf = r->req->fid->aux;
okresp = rxlen >= 9 && t == SSH_FXP_STATUS && GET4(rxpkt+5) == SSH_FX_OK;
switch(r->req->ifcall.type){
case Tattach:
if(t != SSH_FXP_ATTRS) goto common;
if(attrfixupqid(&r->req->ofcall.qid) < 0)
goto garbage;
r->req->aux = (void*)-1;
if((r->req->ofcall.qid.type & QTDIR) == 0)
respond(r->req, "not a directory");
else
sshfsattach(r->req);
break;
case Twalk:
if(t != SSH_FXP_ATTRS) goto common;
if(r->req->ofcall.nwqid <= 0
|| attrfixupqid(&r->req->ofcall.wqid[r->req->ofcall.nwqid - 1]) < 0)
goto garbage;
walkprocess(r->req, nil);
break;
case Tcreate:
if(okresp && r->req->aux == (void*)-1){
submitreq(r->req);
break;
}
/* wet floor */
case Topen: opendir:
if(t != SSH_FXP_HANDLE) goto common;
if(unpack(rxpkt, rxlen, "_____s", &hand, &handn) < 0) goto garbage;
wlock(sf);
sf->handn = handn;
sf->hand = emalloc9p(sf->handn);
memcpy(sf->hand, hand, sf->handn);
if(r->req->ifcall.type == Tcreate){
s = sf->fn;
sf->fn = pathcat(s, r->req->ifcall.name);
free(s);
sf->qid = (Qid){qidcalc(sf->fn), 0, (r->req->ifcall.perm & DMDIR) != 0 ? QTDIR : 0};
r->req->ofcall.qid = sf->qid;
r->req->fid->qid = sf->qid;
}
wunlock(sf);
if(r->req->ifcall.type == Tread){
r->req->aux = nil;
readprocess(r->req);
}else
respond(r->req, nil);
break;
case Tread:
if((r->req->fid->qid.type & QTDIR) != 0){
if(r->req->aux == (void*)-1){
if(t != SSH_FXP_STATUS) goto common;
/* reopen even if close failed */
r->req->aux = (void*)-2;
submitreq(r->req);
}else if(r->req->aux == (void*)-2)
goto opendir;
else{
if(t != SSH_FXP_NAME) goto common;
if(parsedir(sf) < 0) goto garbage;
readprocess(r->req);
}
break;
}
if(t != SSH_FXP_DATA) goto common;
if(unpack(rxpkt, rxlen, "_____s", &msg, &msgn) < 0) goto garbage;
if(msgn > r->req->ifcall.count) msgn = r->req->ifcall.count;
r->req->ofcall.count = msgn;
memcpy(r->req->ofcall.data, msg, msgn);
respond(r->req, nil);
break;
case Twrite:
if(t != SSH_FXP_STATUS) goto common;
if(okresp){
r->req->ofcall.count += r->req->ofcall.offset;
if(r->req->ofcall.count == r->req->ifcall.count)
respond(r->req, nil);
else
submitreq(r->req);
break;
}
if(r->req->ofcall.count == 0) goto common;
respond(r->req, nil);
break;
case Tstat:
if(t != SSH_FXP_ATTRS) goto common;
if(attrib2dir(rxpkt + 5, rxpkt + rxlen, &r->req->d) < 0) goto garbage;
respond(r->req, nil);
break;
case Twstat:
if(!okresp) goto common;
if(!r->req->d.name[0]){
respond(r->req, nil);
break;
}
if(r->req->aux == nil){
r->req->aux = (void*)-1;
submitreq(r->req);
}else{
wlock(sf);
free(sf->fn);
sf->fn = r->req->aux;
wunlock(sf);
respond(r->req, nil);
}
break;
case Tremove:
goto common;
default:
fprint(2, "sendproc: unimplemented 9p request %F in queue\n", &r->req->ifcall);
respond(r->req, "phase error");
}
putsreq(r);
continue;

common:
switch(t){
case SSH_FXP_STATUS:
if(unpack(rxpkt, rxlen, "_____uss", &code, &msg, &msgn, &lang, &langn) < 0){
garbage:
fprint(2, "sshfs: garbled packet in response to 9p request %F\n", &r->req->ifcall);
break;
}
if(code == SSH_FX_OK)
e = nil;
else if(code == SSH_FX_EOF && r->req->ifcall.type == Tread){
if((r->req->fid->qid.type & QTDIR) != 0){
wlock(sf);
sf->direof = 1;
wunlock(sf);
readprocess(r->req);
putsreq(r);
continue;
}
r->req->ofcall.count = 0;
e = nil;
}else if(msgn > 0){
e = msg;
e[msgn] = 0;
}else if(code < nelem(errors))
e = errors[code];
else{
snprint(ebuf, sizeof(ebuf), "error code %d", code);
e = ebuf;
}
break;
default:
fprint(2, "sshfs: received unexpected packet %Σ for 9p request %F\n", t, &r->req->ifcall);
}
if(r->req->ifcall.type == Twalk)
walkprocess(r->req, e);
else
respond(r->req, e);
putsreq(r);
continue;
}
}

void
sshfswalk(Req *r)
{
SFid *s, *t;
char *p, *q;
int i;

if(r->fid != r->newfid){
r->newfid->qid = r->fid->qid;
s = r->fid->aux;
t = emalloc9p(sizeof(SFid));
t->fn = estrdup9p(s->fn);
t->qid = s->qid;
r->newfid->aux = t;
}else
t = r->fid->aux;
if(r->ifcall.nwname == 0){
respond(r, nil);
return;
}
p = estrdup9p(t->fn);
for(i = 0; i < r->ifcall.nwname; i++){
q = pathcat(p, r->ifcall.wname[i]);
free(p);
p = q;
r->ofcall.wqid[i] = (Qid){qidcalc(p), 0, QTDIR};
}
r->ofcall.nwqid = r->ifcall.nwname;
r->aux = p;
submitreq(r);
}

void
sshfsdestroyfid(Fid *f)
{
SFid *sf;
SReq *sr;

sf = f->aux;
if(sf == nil)
return;
if(sf->hand != nil){
sr = emalloc9p(sizeof(SReq));
sr->closefid = sf;
submitsreq(sr);
}else
putsfid(sf);
}

void
sshfsdestroyreq(Req *r)
{
if(r->ifcall.type == Twalk)
free(r->aux);
}

void
sshfsstart(Srv *)
{
proccreate(sendproc, nil, mainstacksize);
proccreate(recvproc, nil, mainstacksize);
}

void
sshfsend(Srv *)
{
dprint("sshfs: ending\n");
threadexitsall(nil);
}

Srv sshfssrv = {
.start sshfsstart,
.attach sshfsattach,
.walk sshfswalk,
.open submitreq,
.create submitreq,
.read sshfsread,
.write submitreq,
.stat submitreq,
.wstat submitreq,
.remove submitreq,
.destroyfid sshfsdestroyfid,
.destroyreq sshfsdestroyreq,
.end sshfsend,
};

char *
readfile(char *fn)
{
char *hand, *dat;
int handn, datn;
u32int code;
char *p;
int off;

if(fn == nil) return nil;
sendpkt("busuu", SSH_FXP_OPEN, 0, fn, strlen(fn), SSH_FXF_READ, 0);
if(recvpkt() != SSH_FXP_HANDLE) return nil;
if(unpack(rxpkt, rxlen, "_____s", &dat, &handn) < 0) return nil;
hand = emalloc9p(handn);
memcpy(hand, dat, handn);
off = 0;
p = nil;
for(;;){
sendpkt("busvu", SSH_FXP_READ, 0, hand, handn, (uvlong)off, MAXWRITE);
switch(recvpkt()){
case SSH_FXP_STATUS:
if(unpack(rxpkt, rxlen, "_____u", &code) < 0) goto err;
if(code == SSH_FX_EOF) goto out;
default:
goto err;
case SSH_FXP_DATA:
if(unpack(rxpkt, rxlen, "_____s", &dat, &datn) < 0) goto err;
break;
}
p = erealloc9p(p, off + datn + 1);
memcpy(p + off, dat, datn);
off += datn;
p[off] = 0;
}
err:
p = nil;
out:
sendpkt("bus", SSH_FXP_CLOSE, 0, hand, handn);
free(hand);
recvpkt();
return p;
}

void
passwdparse(IDEnt **tab, char *s)
{
IDEnt *e, **b;
char *p, *n;
int id;

if(s == nil)
return;
for(p = s;;){
n = p;
p = strpbrk(p, ":\n"); if(p == nil) break; if(*p != ':'){ p++; continue; }
*p = 0;
p = strpbrk(p+1, ":\n");
p = strpbrk(p, ":\n"); if(p == nil) break; if(*p != ':'){ p++; continue; }
id = strtol(p+1, &p, 10);
p = strchr(p, '\n');
if(p == nil) break;
p++;
e = emalloc9p(sizeof(IDEnt));
e->name = estrdup9p(n);
e->id = id;
b = &tab[((ulong)e->id) % HASH];
e->next = *b;
*b = e;
}
free(s);
}

int pfd[2];
int sshargc;
char **sshargv;

void
startssh(void *)
{
char *f;

close(pfd[0]);
dup(pfd[1], 0);
dup(pfd[1], 1);
close(pfd[1]);
if(strncmp(sshargv[0], "./", 2) != 0)
f = smprint("/bin/%s", sshargv[0]);
else
f = sshargv[0];
procexec(nil, f, sshargv);
sysfatal("exec: %r");
}

void
usage(void)
{
static char *common = "[-abdRUG] [-s service] [-m mtpt] [-u uidfile] [-g gidfile]";
fprint(2, "usage: %s %s [-- ssh-options] [user@]host\n", argv0, common);
fprint(2, " %s %s -c cmdline\n", argv0, common);
fprint(2, " %s %s -p\n", argv0, common);
threadexits("usage");
}

void
threadmain(int argc, char **argv)
{
u32int x;
static int pflag, cflag;
static char *svc, *mtpt;
static int mflag;
static char *uidfile, *gidfile;

fmtinstall(L'Σ', fxpfmt);

mtpt = "/n/ssh";
uidfile = "/etc/passwd";
gidfile = "/etc/group";
ARGBEGIN{
case 'R': readonly++; break;
case 'd': debug++; chatty9p++; break;
case 'p': pflag++; break;
case 'c': cflag++; break;
case 's': svc = EARGF(usage()); break;
case 'a': mflag |= MAFTER; break;
case 'b': mflag |= MBEFORE; break;
case 'm': mtpt = EARGF(usage()); break;
case 'M': mtpt = nil; break;
case 'u': uidfile = EARGF(usage()); break;
case 'U': uidfile = nil; break;
case 'g': gidfile = EARGF(usage()); break;
case 'G': gidfile = nil; break;
case 'r': root = EARGF(usage()); break;
default: usage();
}ARGEND;

if(readonly){
sshfssrv.create = nil;
sshfssrv.write = nil;
sshfssrv.wstat = nil;
sshfssrv.remove = nil;
}

if(pflag){
rdfd = 0;
wrfd = 1;
}else{
if(argc == 0) usage();
if(cflag){
sshargc = argc;
sshargv = argv;
}else{
sshargc = argc + 2;
sshargv = emalloc9p(sizeof(char *) * (sshargc + 1));
sshargv[0] = "ssh";
memcpy(sshargv + 1, argv, argc * sizeof(char *));
sshargv[sshargc - 1] = "#sftp";
}
pipe(pfd);
rdfd = wrfd = pfd[0];
procrfork(startssh, nil, mainstacksize, RFFDG|RFNOTEG|RFNAMEG);
close(pfd[1]);
}

sendpkt("bu", SSH_FXP_INIT, VERSION);
if(recvpkt() != SSH_FXP_VERSION || unpack(rxpkt, rxlen, "_u", &x) < 0) sysfatal("received garbage");
if(x != VERSION) sysfatal("server replied with incompatible version %d", x);

passwdparse(uidtab, readfile(uidfile));
passwdparse(gidtab, readfile(gidfile));

threadpostmountsrv(&sshfssrv, svc, mtpt, MCREATE | mflag);

threadexits(nil);
}