Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <auth.h>
#include "authlocal.h"

enum {
        ARgiveup = 100,
};

static uchar*
gstring(uchar *p, uchar *ep, char **s)
{
        uint n;

        if(p == nil)
                return nil;
        if(p+BIT16SZ > ep)
                return nil;
        n = GBIT16(p);
        p += BIT16SZ;
        if(p+n > ep)
                return nil;
        *s = malloc(n+1);
        memmove((*s), p, n);
        (*s)[n] = '\0';
        p += n;
        return p;
}

static uchar*
gcarray(uchar *p, uchar *ep, uchar **s, int *np)
{
        uint n;

        if(p == nil)
                return nil;
        if(p+BIT16SZ > ep)
                return nil;
        n = GBIT16(p);
        p += BIT16SZ;
        if(p+n > ep)
                return nil;
        *s = malloc(n);
        if(*s == nil)
                return nil;
        memmove((*s), p, n);
        *np = n;
        p += n;
        return p;
}

void
auth_freeAI(AuthInfo *ai)
{
        if(ai == nil)
                return;
        free(ai->cuid);
        free(ai->suid);
        free(ai->cap);
        free(ai->secret);
        free(ai);
}

static uchar*
convM2AI(uchar *p, int n, AuthInfo **aip)
{
        uchar *e = p+n;
        AuthInfo *ai;

        ai = mallocz(sizeof(*ai), 1);
        if(ai == nil)
                return nil;

        p = gstring(p, e, &ai->cuid);
        p = gstring(p, e, &ai->suid);
        p = gstring(p, e, &ai->cap);
        p = gcarray(p, e, &ai->secret, &ai->nsecret);
        if(p == nil)
                auth_freeAI(ai);
        else
                *aip = ai;
        return p;
}

AuthInfo*
auth_getinfo(AuthRpc *rpc)
{
        AuthInfo *a;

        if(auth_rpc(rpc, "authinfo", nil, 0) != ARok)
                return nil;
        if(convM2AI((uchar*)rpc->arg, rpc->narg, &a) == nil){
                werrstr("bad auth info from factotum");
                return nil;
        }
        return a;
}

static int
dorpc(AuthRpc *rpc, char *verb, char *val, int len, AuthGetkey *getkey)
{
        int ret;

        for(;;){
                if((ret = auth_rpc(rpc, verb, val, len)) != ARneedkey && ret != ARbadkey)
                        return ret;
                if(getkey == nil)
                        return ARgiveup;        /* don't know how */
                if((*getkey)(rpc->arg) < 0)
                        return ARgiveup;        /* user punted */
        }
}

/*
 *  this just proxies what the factotum tells it to.
 */
AuthInfo*
fauth_proxy(int fd, AuthRpc *rpc, AuthGetkey *getkey, char *params)
{
        char *buf;
        int m, n, ret;
        AuthInfo *a;
        char oerr[ERRMAX];

        if(rpc == nil){
                werrstr("fauth_proxy - no factotum");
                return nil;
        }

        rerrstr(oerr, sizeof oerr);
        werrstr("UNKNOWN AUTH ERROR");

        if(dorpc(rpc, "start", params, strlen(params), getkey) != ARok){
                werrstr("fauth_proxy start: %r");
                return nil;
        }

        buf = malloc(AuthRpcMax);
        if(buf == nil)
                return nil;
        for(;;){
                switch(dorpc(rpc, "read", nil, 0, getkey)){
                case ARdone:
                        free(buf);
                        a = auth_getinfo(rpc);
                        /* no error, restore whatever was there */
                        errstr(oerr, sizeof oerr);
                        return a;
                case ARok:
                        if(write(fd, rpc->arg, rpc->narg) != rpc->narg){
                                werrstr("auth_proxy write fd: %r");
                                goto Error;
                        }
                        break;
                case ARphase:
                        n = 0;
                        memset(buf, 0, AuthRpcMax);
                        while((ret = dorpc(rpc, "write", buf, n, getkey)) == ARtoosmall){
                                if(atoi(rpc->arg) > AuthRpcMax)
                                        break;
                                m = read(fd, buf + n, atoi(rpc->arg) - n);
                                if(m <= 0){
                                        if(m == 0)
                                                werrstr("auth_proxy short read: %s",
                                                        buf);
                                        goto Error;
                                }
                                n += m;
                        }
                        if(ret != ARok){
                                werrstr("auth_proxy rpc write: %s: %r", buf);
                                goto Error;
                        }
                        break;
                default:
                        werrstr("auth_proxy rpc: %r");
                        goto Error;
                }
        }
Error:
        free(buf);
        return nil;
}

AuthInfo*
auth_proxy(int fd, AuthGetkey *getkey, char *fmt, ...)
{
        int afd;
        char *p;
        va_list arg;
        AuthInfo *ai;
        AuthRpc *rpc;

        quotefmtinstall();      /* just in case */
        va_start(arg, fmt);
        p = vsmprint(fmt, arg);
        va_end(arg);

        ai = nil;
        afd = open("/mnt/factotum/rpc", ORDWR);
        if(afd < 0){
                werrstr("opening /mnt/factotum/rpc: %r");
                free(p);
                return nil;
        }

        rpc = auth_allocrpc(afd);
        if(rpc){
                ai = fauth_proxy(fd, rpc, getkey, p);
                auth_freerpc(rpc);
        }
        close(afd);
        free(p);
        return ai;
}