ref: 50791b875552b0dc5748aa67c95776736f6ff4b7
dir: /sys/src/cmd/auth/factotum/rpc.c/
/*
* Factotum RPC
*
* Must be paired write/read cycles on /mnt/factotum/rpc.
* The format of a request is verb, single space, data.
* Data format is verb-dependent; in particular, it can be binary.
* The format of a response is the same. The write only sets up
* the RPC. The read tries to execute it. If the /mnt/factotum/key
* file is open, we ask for new keys using that instead of returning
* an error in the RPC. This means the read blocks.
* Textual arguments are parsed with tokenize, so rc-style quoting
* rules apply.
*
* Only authentication protocol messages go here. Configuration
* is still via ctl (below).
*
* Return values are:
* error message - an error happened.
* ok [data] - success, possible data is request dependent.
* needkey proto domain user - request aborted, get me this key and try again
* badkey proto domain user - request aborted, this key might be bad
* done [haveai] - authentication is done [haveai: you can get an ai with authinfo]
* Request RPCs are:
* start attrs - initializes protocol for authentication, can fail.
* returns "ok read" or "ok write" on success.
* read - execute protocol read
* write - execute protocol write
* authinfo - if the protocol is finished, return the AI if any
* attr - return protocol information
*/
#include "dat.h"
Req *rpcwait;
typedef struct Verb Verb;
struct Verb {
char *verb;
int iverb;
};
enum {
Vunknown = -1,
Vauthinfo = 0,
Vread,
Vstart,
Vwrite,
Vattr,
};
Verb rpctab[] = {
"authinfo", Vauthinfo,
"read", Vread,
"start", Vstart,
"write", Vwrite,
"attr", Vattr,
};
static int
classify(char *s, Verb *verbtab, int nverbtab)
{
int i;
for(i=0; i<nverbtab; i++)
if(strcmp(s, verbtab[i].verb) == 0)
return verbtab[i].iverb;
return Vunknown;
}
void
rpcwrite(Req *r)
{
Fsstate *fss;
if(r->ifcall.count >= Maxrpc){
respond(r, Etoolarge);
return;
}
fss = r->fid->aux;
if(fss->pending){
respond(r, "rpc already pending; read to clear");
return;
}
memmove(fss->rpc.buf, r->ifcall.data, r->ifcall.count);
fss->rpc.buf[r->ifcall.count] = '\0';
fss->rpc.verb = fss->rpc.buf;
if(fss->rpc.arg = strchr(fss->rpc.buf, ' ')){
*fss->rpc.arg++ = '\0';
fss->rpc.narg = r->ifcall.count - (fss->rpc.arg - fss->rpc.buf);
}else{
fss->rpc.arg = "";
fss->rpc.narg = 0;
}
fss->rpc.iverb = classify(fss->rpc.verb, rpctab, nelem(rpctab));
r->ofcall.count = r->ifcall.count;
fss->pending = 1;
respond(r, nil);
}
static void
retstring(Req *r, Fsstate *fss, char *s)
{
int n;
n = strlen(s);
if(n > r->ifcall.count)
n = r->ifcall.count;
memmove(r->ofcall.data, s, n);
r->ofcall.count = n;
fss->pending = 0;
respond(r, nil);
return;
}
void
retrpc(Req *r, int ret, Fsstate *fss)
{
switch(ret){
default:
snprint(fss->rpc.buf, Maxrpc, "internal error %d", ret);
retstring(r, fss, fss->rpc.buf);
return;
case RpcErrstr:
snprint(fss->rpc.buf, Maxrpc, "error %r");
retstring(r, fss, fss->rpc.buf);
return;
case RpcFailure:
snprint(fss->rpc.buf, Maxrpc, "error %s", fss->err);
retstring(r, fss, fss->rpc.buf);
return;
case RpcNeedkey:
if(needkeyqueue(r, fss) < 0){
snprint(fss->rpc.buf, Maxrpc, "needkey %s", fss->keyinfo);
retstring(r, fss, fss->rpc.buf);
}
return;
case RpcOk:
retstring(r, fss, "ok");
return;
case RpcToosmall:
snprint(fss->rpc.buf, Maxrpc, "toosmall %d", fss->rpc.nwant);
retstring(r, fss, fss->rpc.buf);
return;
case RpcPhase:
snprint(fss->rpc.buf, Maxrpc, "phase %r");
retstring(r, fss, fss->rpc.buf);
return;
case RpcConfirm:
confirmqueue(r, fss);
return;
}
}
int
rdwrcheck(Req *r, Fsstate *fss)
{
if(fss->ps == nil){
retstring(r, fss, "error no current protocol");
return -1;
}
if(fss->phase == Notstarted){
retstring(r, fss, "protocol not started");
return -1;
}
if(fss->phase == Broken){
snprint(fss->rpc.buf, Maxrpc, "error %s", fss->err);
retstring(r, fss, fss->rpc.buf);
return -1;
}
if(fss->phase == Established){
if(fss->haveai)
retstring(r, fss, "done haveai");
else
retstring(r, fss, "done");
return -1;
}
return 0;
}
static void
logret(char *pre, Fsstate *fss, int ret)
{
switch(ret){
default:
flog("%s: code %d", pre, ret);
break;
case RpcErrstr:
flog("%s: error %r", pre);
break;
case RpcFailure:
flog("%s: failure %s", pre, fss->err);
break;
case RpcNeedkey:
flog("%s: needkey %s", pre, fss->keyinfo);
break;
case RpcOk:
flog("%s: ok", pre);
break;
case RpcToosmall:
flog("%s: toosmall %d", pre, fss->rpc.nwant);
break;
case RpcPhase:
flog("%s: phase: %r", pre);
break;
case RpcConfirm:
flog("%s: waiting for confirm", pre);
break;
}
}
void
rpcrdwrlog(Fsstate *fss, char *rdwr, uint n, int ophase, int ret)
{
char buf0[40], buf1[40], pre[300];
if(!debug)
return;
snprint(pre, sizeof pre, "%d: %s %ud in phase %s yields phase %s",
fss->seqnum, rdwr, n, phasename(fss, ophase, buf0), phasename(fss, fss->phase, buf1));
logret(pre, fss, ret);
}
void
rpcstartlog(Attr *attr, Fsstate *fss, int ret)
{
char pre[300], tmp[40];
if(!debug)
return;
snprint(pre, sizeof pre, "%d: start %A yields phase %s", fss->seqnum,
attr, phasename(fss, fss->phase, tmp));
logret(pre, fss, ret);
}
int seqnum;
void
rpcread(Req *r)
{
Attr *attr;
char *p;
int ophase, ret;
uchar *e;
uint count;
Fsstate *fss;
Proto *proto;
if(r->ifcall.count < 64){
respond(r, "rpc read too small");
return;
}
fss = r->fid->aux;
if(!fss->pending){
respond(r, "no rpc pending");
return;
}
switch(fss->rpc.iverb){
default:
case Vunknown:
retstring(r, fss, "error unknown verb");
break;
case Vstart:
if(fss->phase != Notstarted){
flog("%d: implicit close due to second start; old attr '%A'", fss->seqnum, fss->attr);
if(fss->proto && fss->ps)
(*fss->proto->close)(fss);
fss->ps = nil;
fss->proto = nil;
_freeattr(fss->attr);
fss->attr = nil;
fss->phase = Notstarted;
}
attr = _parseattr(fss->rpc.arg);
if((p = _strfindattr(attr, "proto")) == nil){
retstring(r, fss, "error did not specify proto");
_freeattr(attr);
break;
}
if((proto = findproto(p)) == nil){
snprint(fss->rpc.buf, Maxrpc, "error unknown protocol %q", p);
retstring(r, fss, fss->rpc.buf);
_freeattr(attr);
break;
}
fss->attr = attr;
fss->proto = proto;
fss->seqnum = ++seqnum;
ret = (*proto->init)(proto, fss);
rpcstartlog(attr, fss, ret);
if(ret != RpcOk){
_freeattr(fss->attr);
fss->attr = nil;
fss->phase = Notstarted;
}
retrpc(r, ret, fss);
break;
case Vread:
if(fss->rpc.arg && fss->rpc.arg[0]){
retstring(r, fss, "error read needs no parameters");
break;
}
if(rdwrcheck(r, fss) < 0)
break;
count = r->ifcall.count - 3;
ophase = fss->phase;
ret = fss->proto->read(fss, (uchar*)r->ofcall.data+3, &count);
rpcrdwrlog(fss, "read", count, ophase, ret);
if(ret == RpcOk){
memmove(r->ofcall.data, "ok ", 3);
if(count == 0)
r->ofcall.count = 2;
else
r->ofcall.count = 3+count;
fss->pending = 0;
respond(r, nil);
}else
retrpc(r, ret, fss);
break;
case Vwrite:
if(rdwrcheck(r, fss) < 0)
break;
ophase = fss->phase;
ret = fss->proto->write(fss, fss->rpc.arg, fss->rpc.narg);
rpcrdwrlog(fss, "write", fss->rpc.narg, ophase, ret);
retrpc(r, ret, fss);
break;
case Vauthinfo:
if(fss->phase != Established){
retstring(r, fss, "error authentication unfinished");
break;
}
if(!fss->haveai){
retstring(r, fss, "error no authinfo available");
break;
}
memmove(r->ofcall.data, "ok ", 3);
fss->ai.cap = mkcap(r->fid->uid, fss->ai.suid);
e = convAI2M(&fss->ai, (uchar*)r->ofcall.data+3, r->ifcall.count-3);
free(fss->ai.cap);
fss->ai.cap = nil;
if(e == nil){
retstring(r, fss, "error read too small");
break;
}
r->ofcall.count = e - (uchar*)r->ofcall.data;
fss->pending = 0;
respond(r, nil);
break;
case Vattr:
snprint(fss->rpc.buf, Maxrpc, "ok %A", fss->attr);
retstring(r, fss, fss->rpc.buf);
break;
}
}
enum {
Vdelkey,
Vaddkey,
Vdebug,
};
Verb ctltab[] = {
"delkey", Vdelkey,
"key", Vaddkey,
"debug", Vdebug,
};
/*
* key attr=val... - add a key
* the attr=val pairs are protocol-specific.
* for example, both of these are valid:
* key p9sk1 gre cs.bell-labs.com mysecret
* key p9sk1 gre cs.bell-labs.com 11223344556677 fmt=des7hex
* delkey ... - delete a key
* if given, the attr=val pairs are used to narrow the search
* [maybe should require a password?]
*/
int
ctlwrite(char *a, int atzero)
{
char *p;
int i, nmatch, ret;
Attr *attr, **l, **lpriv, **lprotos, *pa, *priv, *protos;
Key *k;
Proto *proto;
if(a[0] == '#' || a[0] == '\0')
return 0;
/*
* it would be nice to emit a warning of some sort here.
* we ignore all but the first line of the write. this helps
* both with things like "echo delkey >/mnt/factotum/ctl"
* and writes that (incorrectly) contain multiple key lines.
*/
if(p = strchr(a, '\n')){
if(p[1] != '\0'){
werrstr("multiline write not allowed");
return -1;
}
*p = '\0';
}
if((p = strchr(a, ' ')) == nil)
p = "";
else
*p++ = '\0';
switch(classify(a, ctltab, nelem(ctltab))){
default:
case Vunknown:
werrstr("unknown verb");
return -1;
case Vdebug:
debug ^= 1;
return 0;
case Vdelkey:
nmatch = 0;
attr = _parseattr(p);
for(pa=attr; pa; pa=pa->next){
if(pa->type != AttrQuery && pa->name[0]=='!'){
werrstr("only !private? patterns are allowed for private fields");
_freeattr(attr);
return -1;
}
}
Again:
qlock(ring);
for(i=0; i<ring->nkey; i++){
k = ring->key[i];
if(matchattr(attr, k->attr, k->privattr)){
nmatch++;
ring->nkey--;
memmove(&ring->key[i], &ring->key[i+1], (ring->nkey-i)*sizeof(ring->key[0]));
qunlock(ring);
closekey(k);
goto Again;
}
}
qunlock(ring);
_freeattr(attr);
if(nmatch == 0){
werrstr("found no keys to delete");
return -1;
}
return 0;
case Vaddkey:
attr = _parseattr(p);
/* separate out proto= attributes */
lprotos = &protos;
for(l=&attr; (*l); ){
if(strcmp((*l)->name, "proto") == 0){
*lprotos = *l;
lprotos = &(*l)->next;
*l = (*l)->next;
}else
l = &(*l)->next;
}
*lprotos = nil;
if(protos == nil){
werrstr("key without protos");
_freeattr(attr);
return -1;
}
/* separate out private attributes */
lpriv = &priv;
for(l=&attr; (*l); ){
if((*l)->name[0] == '!'){
*lpriv = *l;
lpriv = &(*l)->next;
*l = (*l)->next;
}else
l = &(*l)->next;
}
*lpriv = nil;
/* add keys */
ret = 0;
for(pa=protos; pa; pa=pa->next){
if((proto = findproto(pa->val)) == nil){
werrstr("unknown proto %s", pa->val);
ret = -1;
continue;
}
if(proto->addkey == nil){
werrstr("proto %s doesn't take keys", proto->name);
ret = -1;
continue;
}
k = emalloc(sizeof(Key));
k->attr = _mkattr(AttrNameval, "proto", proto->name, _copyattr(attr));
k->privattr = _copyattr(priv);
k->ref = 1;
k->proto = proto;
if(proto->addkey(k, atzero) < 0){
ret = -1;
closekey(k);
continue;
}
closekey(k);
}
_freeattr(attr);
_freeattr(priv);
_freeattr(protos);
return ret;
}
}