ref: 600bbfe4aaa9ad0f73d8d73eef1b7670e5f7d3a3
dir: /os/port/dial.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
#include "kernel.h"
typedef struct DS DS;
static int call(char*, char*, DS*);
static int csdial(DS*);
static void _dial_string_parse(char*, DS*);
static int nettrans(char*, char*, int na, char*, int);
enum
{
Maxstring= 128,
Maxpath= 100
};
struct DS
{
char buf[Maxstring]; /* dist string */
char *netdir;
char *proto;
char *rem;
char *local; /* other args */
char *dir;
int *cfdp;
};
/*
* the dialstring is of the form '[/net/]proto!dest'
*/
int
kdial(char *dest, char *local, char *dir, int *cfdp)
{
DS ds;
int rv;
char err[ERRMAX], alterr[ERRMAX];
ds.local = local;
ds.dir = dir;
ds.cfdp = cfdp;
_dial_string_parse(dest, &ds);
if(ds.netdir)
return csdial(&ds);
ds.netdir = "/net";
rv = csdial(&ds);
if(rv >= 0)
return rv;
err[0] = 0;
kerrstr(err, sizeof err);
if(strstr(err, "refused") != 0){
kerrstr(err, sizeof err);
return rv;
}
ds.netdir = "/net.alt";
rv = csdial(&ds);
if(rv >= 0)
return rv;
alterr[0] = 0;
kerrstr(alterr, sizeof err);
if(strstr(alterr, "translate") || strstr(alterr, "does not exist"))
kerrstr(err, sizeof err);
else
kerrstr(alterr, sizeof alterr);
return rv;
}
static int
csdial(DS *ds)
{
int n, fd, rv;
char *p, buf[Maxstring], clone[Maxpath], err[ERRMAX], besterr[ERRMAX];
/*
* open connection server
*/
snprint(buf, sizeof(buf), "%s/cs", ds->netdir);
fd = kopen(buf, ORDWR);
if(fd < 0){
/* no connection server, don't translate */
snprint(clone, sizeof(clone), "%s/%s/clone", ds->netdir, ds->proto);
return call(clone, ds->rem, ds);
}
/*
* ask connection server to translate
*/
sprint(buf, "%s!%s", ds->proto, ds->rem);
if(kwrite(fd, buf, strlen(buf)) < 0){
kerrstr(err, sizeof err);
kclose(fd);
kwerrstr("%s (%s)", err, buf);
return -1;
}
/*
* loop through each address from the connection server till
* we get one that works.
*/
*besterr = 0;
strcpy(err, Egreg);
rv = -1;
kseek(fd, 0, 0);
while((n = kread(fd, buf, sizeof(buf) - 1)) > 0){
buf[n] = 0;
p = strchr(buf, ' ');
if(p == 0)
continue;
*p++ = 0;
rv = call(buf, p, ds);
if(rv >= 0)
break;
err[0] = 0;
kerrstr(err, sizeof err);
if(strstr(err, "does not exist") == 0)
memmove(besterr, err, sizeof besterr);
}
kclose(fd);
if(rv < 0 && *besterr)
kerrstr(besterr, sizeof besterr);
else
kerrstr(err, sizeof err);
return rv;
}
static int
call(char *clone, char *dest, DS *ds)
{
int fd, cfd, n;
char name[Maxpath], data[Maxpath], err[ERRMAX], *p;
cfd = kopen(clone, ORDWR);
if(cfd < 0){
kerrstr(err, sizeof err);
kwerrstr("%s (%s)", err, clone);
return -1;
}
/* get directory name */
n = kread(cfd, name, sizeof(name)-1);
if(n < 0){
kerrstr(err, sizeof err);
kclose(cfd);
kwerrstr("read %s: %s", clone, err);
return -1;
}
name[n] = 0;
for(p = name; *p == ' '; p++)
;
sprint(name, "%d", strtoul(p, 0, 0));
p = strrchr(clone, '/');
*p = 0;
if(ds->dir)
snprint(ds->dir, NETPATHLEN, "%s/%s", clone, name);
snprint(data, sizeof(data), "%s/%s/data", clone, name);
/* connect */
if(ds->local)
snprint(name, sizeof(name), "connect %s %s", dest, ds->local);
else
snprint(name, sizeof(name), "connect %s", dest);
if(kwrite(cfd, name, strlen(name)) < 0){
err[0] = 0;
kerrstr(err, sizeof err);
kclose(cfd);
kwerrstr("%s (%s)", err, name);
return -1;
}
/* open data connection */
fd = kopen(data, ORDWR);
if(fd < 0){
err[0] = 0;
kerrstr(err, sizeof err);
kwerrstr("%s (%s)", err, data);
kclose(cfd);
return -1;
}
if(ds->cfdp)
*ds->cfdp = cfd;
else
kclose(cfd);
return fd;
}
/*
* parse a dial string
*/
static void
_dial_string_parse(char *str, DS *ds)
{
char *p, *p2;
strncpy(ds->buf, str, Maxstring);
ds->buf[Maxstring-1] = 0;
p = strchr(ds->buf, '!');
if(p == 0) {
ds->netdir = 0;
ds->proto = "net";
ds->rem = ds->buf;
} else {
if(*ds->buf != '/' && *ds->buf != '#'){
ds->netdir = 0;
ds->proto = ds->buf;
} else {
for(p2 = p; *p2 != '/'; p2--)
;
*p2++ = 0;
ds->netdir = ds->buf;
ds->proto = p2;
}
*p = 0;
ds->rem = p + 1;
}
}
/*
* announce a network service.
*/
int
kannounce(char *addr, char *dir)
{
int ctl, n, m;
char buf[NETPATHLEN];
char buf2[Maxpath];
char netdir[NETPATHLEN];
char naddr[Maxpath];
char *cp;
/*
* translate the address
*/
if(nettrans(addr, naddr, sizeof(naddr), netdir, sizeof(netdir)) < 0)
return -1;
/*
* get a control channel
*/
ctl = kopen(netdir, ORDWR);
if(ctl<0)
return -1;
cp = strrchr(netdir, '/');
*cp = 0;
/*
* find out which line we have
*/
n = sprint(buf, "%.*s/", sizeof buf, netdir);
m = kread(ctl, &buf[n], sizeof(buf)-n-1);
if(m <= 0){
kclose(ctl);
return -1;
}
buf[n+m] = 0;
/*
* make the call
*/
n = snprint(buf2, sizeof buf2, "announce %s", naddr);
if(kwrite(ctl, buf2, n)!=n){
kclose(ctl);
return -1;
}
/*
* return directory etc.
*/
if(dir)
strcpy(dir, buf);
return ctl;
}
/*
* listen for an incoming call
*/
int
klisten(char *dir, char *newdir)
{
int ctl, n, m;
char buf[NETPATHLEN];
char *cp;
/*
* open listen, wait for a call
*/
snprint(buf, sizeof buf, "%s/listen", dir);
ctl = kopen(buf, ORDWR);
if(ctl < 0)
return -1;
/*
* find out which line we have
*/
strcpy(buf, dir);
cp = strrchr(buf, '/');
*++cp = 0;
n = cp-buf;
m = kread(ctl, cp, sizeof(buf) - n - 1);
if(m <= 0){
kclose(ctl);
return -1;
}
buf[n+m] = 0;
/*
* return directory etc.
*/
if(newdir)
strcpy(newdir, buf);
return ctl;
}
/*
* perform the identity translation (in case we can't reach cs)
*/
static int
identtrans(char *netdir, char *addr, char *naddr, int na, char *file, int nf)
{
char proto[Maxpath];
char *p;
USED(nf);
/* parse the protocol */
strncpy(proto, addr, sizeof(proto));
proto[sizeof(proto)-1] = 0;
p = strchr(proto, '!');
if(p)
*p++ = 0;
snprint(file, nf, "%s/%s/clone", netdir, proto);
strncpy(naddr, p, na);
naddr[na-1] = 0;
return 1;
}
/*
* call up the connection server and get a translation
*/
static int
nettrans(char *addr, char *naddr, int na, char *file, int nf)
{
int i, fd;
char buf[Maxpath];
char netdir[NETPATHLEN];
char *p, *p2;
long n;
/*
* parse, get network directory
*/
p = strchr(addr, '!');
if(p == 0){
kwerrstr("bad dial string: %s", addr);
return -1;
}
if(*addr != '/'){
strcpy(netdir, "/net");
} else {
for(p2 = p; *p2 != '/'; p2--)
;
i = p2 - addr;
if(i == 0 || i >= sizeof(netdir)){
kwerrstr("bad dial string: %s", addr);
return -1;
}
strncpy(netdir, addr, i);
netdir[i] = 0;
addr = p2 + 1;
}
/*
* ask the connection server
*/
sprint(buf, "%s/cs", netdir);
fd = kopen(buf, ORDWR);
if(fd < 0)
return identtrans(netdir, addr, naddr, na, file, nf);
if(kwrite(fd, addr, strlen(addr)) < 0){
kclose(fd);
return -1;
}
kseek(fd, 0, 0);
n = kread(fd, buf, sizeof(buf)-1);
kclose(fd);
if(n <= 0)
return -1;
buf[n] = 0;
/*
* parse the reply
*/
p = strchr(buf, ' ');
if(p == 0)
return -1;
*p++ = 0;
strncpy(naddr, p, na);
naddr[na-1] = 0;
if(buf[0] == '/'){
p = strchr(buf+1, '/');
if(p == nil)
p = buf;
else
p++;
}
snprint(file, nf, "%s/%s", netdir, p);
return 0;
}