ref: a291bbdeddfd41a2f0907ecbd7b819f0eedffdaf
dir: /sys/src/cmd/auth/factotum/p9any.c/
/*
* p9any - protocol negotiator.
*
* Protocol:
* Server->Client: list of proto@domain, tokenize separated, nul terminated
* Client->Server: proto domain, tokenize separated (not proto@domain), nul terminated
*
* Server protocol:
* read list of protocols.
* write null-terminated
*/
#include "dat.h"
static Proto *negotiable[] = {
&p9sk1, /* has to be first because of drawterm bug */
&dp9ik,
};
struct State
{
Fsstate subfss;
State *substate; /* be very careful; this is not one of our States */
Proto *subproto;
int keyasked;
String *subdom;
int version;
};
enum
{
CNeedProtos,
CHaveProto,
CNeedOK,
CRelay,
SHaveProtos,
SNeedProto,
SHaveOK,
SRelay,
Maxphase,
};
static char *phasenames[Maxphase] =
{
[CNeedProtos] "CNeedProtos",
[CHaveProto] "CHaveProto",
[CNeedOK] "CNeedOK",
[CRelay] "CRelay",
[SHaveProtos] "SHaveProtos",
[SNeedProto] "SNeedProto",
[SHaveOK] "SHaveOK",
[SRelay] "SRelay",
};
static int
p9anyinit(Proto*, Fsstate *fss)
{
int iscli;
State *s;
if((iscli = isclient(_strfindattr(fss->attr, "role"))) < 0)
return failure(fss, nil);
s = emalloc(sizeof *s);
fss = fss;
fss->phasename = phasenames;
fss->maxphase = Maxphase;
if(iscli)
fss->phase = CNeedProtos;
else
fss->phase = SHaveProtos;
s->version = 1;
fss->ps = s;
return RpcOk;
}
static void
p9anyclose(Fsstate *fss)
{
State *s;
s = fss->ps;
if(s->subproto && s->subfss.ps && s->subproto->close)
(*s->subproto->close)(&s->subfss);
s->subproto = nil;
s->substate = nil;
s_free(s->subdom);
s->subdom = nil;
s->keyasked = 0;
memset(&s->subfss, 0, sizeof s->subfss);
free(s);
}
static void
setupfss(Fsstate *fss, State *s, Key *k)
{
fss->attr = setattr(fss->attr, "proto=%q", s->subproto->name);
fss->attr = setattr(fss->attr, "dom=%q", _strfindattr(k->attr, "dom"));
s->subfss.attr = fss->attr;
s->subfss.proto = s->subproto;
s->subfss.phase = Notstarted;
s->subfss.sysuser = fss->sysuser;
s->subfss.seqnum = fss->seqnum;
s->subfss.conf = fss->conf;
s->subfss.nconf = fss->nconf;
}
static int
passret(Fsstate *fss, State *s, int ret)
{
switch(ret){
default:
return ret;
case RpcFailure:
if(s->subfss.phase == Broken)
fss->phase = Broken;
memmove(fss->err, s->subfss.err, sizeof fss->err);
return ret;
case RpcNeedkey:
memmove(fss->keyinfo, s->subfss.keyinfo, sizeof fss->keyinfo);
return ret;
case RpcOk:
if(s->subfss.haveai){
fss->haveai = 1;
fss->ai = s->subfss.ai;
s->subfss.haveai = 0;
}
if(s->subfss.phase == Established)
fss->phase = Established;
return ret;
case RpcToosmall:
fss->rpc.nwant = s->subfss.rpc.nwant;
return ret;
case RpcConfirm:
fss->conf = s->subfss.conf;
fss->nconf = s->subfss.nconf;
return ret;
}
}
static int
p9anyread(Fsstate *fss, void *a, uint *n)
{
int i, m, ophase, ret;
Attr *anew;
Key *k;
Keyinfo ki;
String *negstr;
State *s;
s = fss->ps;
switch(fss->phase){
default:
return phaseerror(fss, "read");
case SHaveProtos:
m = 0;
negstr = s_new();
mkkeyinfo(&ki, fss, nil);
ki.attr = nil;
ki.noconf = 1;
ki.user = nil;
for(i=0; i<nelem(negotiable); i++){
anew = setattr(_copyattr(fss->attr), "proto=%q dom?", negotiable[i]->name);
ki.attr = anew;
for(ki.skip=0; findkey(&k, &ki, nil)==RpcOk; ki.skip++){
if(m++)
s_append(negstr, " ");
s_append(negstr, negotiable[i]->name);
s_append(negstr, "@");
s_append(negstr, _strfindattr(k->attr, "dom"));
closekey(k);
}
_freeattr(anew);
}
if(m == 0){
s_free(negstr);
return failure(fss, Enegotiation);
}
i = s_len(negstr)+1;
if(*n < i){
s_free(negstr);
return toosmall(fss, i);
}
*n = i;
memmove(a, s_to_c(negstr), i+1);
fss->phase = SNeedProto;
s_free(negstr);
return RpcOk;
case CHaveProto:
i = strlen(s->subproto->name)+1+s_len(s->subdom)+1;
if(*n < i)
return toosmall(fss, i);
*n = i;
strcpy(a, s->subproto->name);
strcat(a, " ");
strcat(a, s_to_c(s->subdom));
if(s->version == 1)
fss->phase = CRelay;
else
fss->phase = CNeedOK;
return RpcOk;
case SHaveOK:
i = 3;
if(*n < i)
return toosmall(fss, i);
*n = i;
strcpy(a, "OK");
fss->phase = SRelay;
return RpcOk;
case CRelay:
case SRelay:
ophase = s->subfss.phase;
ret = (*s->subproto->read)(&s->subfss, a, n);
rpcrdwrlog(&s->subfss, "read", *n, ophase, ret);
return passret(fss, s, ret);
}
}
static char*
getdom(char *p)
{
p = strchr(p, '@');
if(p == nil)
return "";
return p+1;
}
static int
findprotox(char *name)
{
int i, len;
char *p;
if(p = strchr(name, '@'))
len = p-name;
else
len = strlen(name);
for(i=0; i<nelem(negotiable); i++)
if(strncmp(negotiable[i]->name, name, len) == 0 && negotiable[i]->name[len] == 0)
return i;
return -1;
}
static Proto*
findneg(char *name)
{
int x = findprotox(name);
if(x >= 0)
return negotiable[x];
return nil;
}
static int
protopref(void *a, void *b)
{
return findprotox(*(char**)b) - findprotox(*(char**)a);
}
static int
p9anywrite(Fsstate *fss, void *va, uint n)
{
char *a, *dom, *user, *token[20];
int asking, i, m, ophase, ret;
Attr *anew, *anewsf, *attr;
Key *k;
Keyinfo ki;
Proto *p;
State *s;
s = fss->ps;
a = va;
switch(fss->phase){
default:
return phaseerror(fss, "write");
case CNeedProtos:
if(n==0 || a[n-1] != '\0')
return toosmall(fss, 2048);
a = estrdup(a);
m = tokenize(a, token, nelem(token));
if(m > 0 && strncmp(token[0], "v.", 2) == 0){
s->version = atoi(token[0]+2);
if(s->version != 2){
free(a);
return failure(fss, "unknown version of p9any");
}
if(--m > 0)
memmove(token, token+1, m*sizeof(token[0]));
}
/* put prefered protocols first */
qsort(token, m, sizeof(token[0]), protopref);
/*
* look for a key
*/
anew = _delattr(_delattr(_copyattr(fss->attr), "proto"), "role");
anewsf = _delattr(_copyattr(anew), "user");
user = _strfindattr(anew, "user");
k = nil;
p = nil;
dom = nil;
for(i=0; i<m; i++){
p = findneg(token[i]);
if(p == nil)
continue;
dom = getdom(token[i]);
ret = RpcFailure;
mkkeyinfo(&ki, fss, nil);
if(user==nil || strcmp(user, fss->sysuser)==0){
ki.attr = anewsf;
ki.user = nil;
ret = findkey(&k, &ki, "proto=%q dom=%q role=speakfor %s",
p->name, dom, p->keyprompt);
}
if(ret == RpcFailure){
ki.attr = anew;
ki.user = fss->sysuser;
ret = findkey(&k, &ki,
"proto=%q dom=%q role=client %s",
p->name, dom, p->keyprompt);
}
if(ret == RpcConfirm){
free(a);
return ret;
}
if(ret == RpcOk)
break;
}
_freeattr(anewsf);
/*
* no acceptable key, go through the proto@domains one at a time.
*/
asking = 0;
if(k == nil){
while(!asking && s->keyasked < m){
p = findneg(token[s->keyasked]);
if(p == nil){
s->keyasked++;
continue;
}
dom = getdom(token[s->keyasked]);
mkkeyinfo(&ki, fss, nil);
ki.attr = anew;
ret = findkey(&k, &ki,
"proto=%q dom=%q role=client %s",
p->name, dom, p->keyprompt);
s->keyasked++;
if(ret == RpcNeedkey){
asking = 1;
break;
}
}
}
if(k == nil){
free(a);
_freeattr(anew);
if(asking)
return RpcNeedkey;
else if(s->keyasked)
return failure(fss, nil);
else
return failure(fss, Enegotiation);
}
s->subdom = s_copy(dom);
s->subproto = p;
free(a);
_freeattr(anew);
setupfss(fss, s, k);
closekey(k);
ret = (*s->subproto->init)(p, &s->subfss);
rpcstartlog(s->subfss.attr, &s->subfss, ret);
if(ret == RpcOk)
fss->phase = CHaveProto;
return passret(fss, s, ret);
case SNeedProto:
if(n==0 || a[n-1] != '\0')
return toosmall(fss, n+1);
a = estrdup(a);
m = tokenize(a, token, nelem(token));
if(m != 2){
free(a);
return failure(fss, Ebadarg);
}
p = findneg(token[0]);
if(p == nil){
free(a);
return failure(fss, Enegotiation);
}
attr = _delattr(_copyattr(fss->attr), "proto");
mkkeyinfo(&ki, fss, nil);
ki.attr = attr;
ki.user = nil;
ret = findkey(&k, &ki, "proto=%q dom=%q role=server", token[0], token[1]);
free(a);
_freeattr(attr);
if(ret == RpcConfirm)
return ret;
if(ret != RpcOk)
return failure(fss, Enegotiation);
s->subproto = p;
setupfss(fss, s, k);
closekey(k);
ret = (*s->subproto->init)(p, &s->subfss);
if(ret == RpcOk){
if(s->version == 1)
fss->phase = SRelay;
else
fss->phase = SHaveOK;
}
return passret(fss, s, ret);
case CNeedOK:
if(n < 3)
return toosmall(fss, 3);
if(strcmp("OK", a) != 0)
return failure(fss, "server gave up");
fss->phase = CRelay;
return RpcOk;
case CRelay:
case SRelay:
ophase = s->subfss.phase;
ret = (*s->subproto->write)(&s->subfss, va, n);
rpcrdwrlog(&s->subfss, "write", n, ophase, ret);
return passret(fss, s, ret);
}
}
Proto p9any =
{
.name= "p9any",
.init= p9anyinit,
.write= p9anywrite,
.read= p9anyread,
.close= p9anyclose,
};