ref: da085a2d4cca788686b8f68b2555040cf29dc16c
dir: /sys/src/cmd/exportfs/oexportfs.c/
/*
* oexportfs - legacy exportfs for cpu and import
*/
#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include <libsec.h>
#define Extern
#include "exportfs.h"
enum {
Encnone,
Encssl,
Enctls,
};
int srvfd = -1;
int nonone = 1;
char *filterp;
char *ealgs = "rc4_256 sha1";
char *aanfilter = "/bin/aan";
int encproto = Encnone;
int readonly;
static char *anstring = "tcp!*!0";
static void
filter(int fd, char *cmd, char *host)
{
char addr[128], buf[256], *s, *file, *argv[16];
int lfd, p[2], len, argc;
if(host == nil){
/* Get a free port and post it to the client. */
if (announce(anstring, addr) < 0)
fatal("filter: Cannot announce %s: %r", anstring);
snprint(buf, sizeof(buf), "%s/local", addr);
if ((lfd = open(buf, OREAD)) < 0)
fatal("filter: Cannot open %s: %r", buf);
if ((len = read(lfd, buf, sizeof buf - 1)) < 0)
fatal("filter: Cannot read %s: %r", buf);
close(lfd);
buf[len] = '\0';
if ((s = strchr(buf, '\n')) != nil)
len = s - buf;
if (write(fd, buf, len) != len)
fatal("filter: cannot write port; %r");
} else {
/* Read address string from connection */
if ((len = read(fd, buf, sizeof buf - 1)) < 0)
sysfatal("filter: cannot write port; %r");
buf[len] = '\0';
if ((s = strrchr(buf, '!')) == nil)
sysfatal("filter: illegally formatted port %s", buf);
strecpy(addr, addr+sizeof(addr), netmkaddr(host, "tcp", s+1));
strecpy(strrchr(addr, '!'), addr+sizeof(addr), s);
}
DEBUG(DFD, "filter: %s\n", addr);
snprint(buf, sizeof(buf), "%s", cmd);
argc = tokenize(buf, argv, nelem(argv)-3);
if (argc == 0)
sysfatal("filter: empty command");
if(host != nil)
argv[argc++] = "-c";
argv[argc++] = addr;
argv[argc] = nil;
file = argv[0];
if((s = strrchr(argv[0], '/')) != nil)
argv[0] = s+1;
if(pipe(p) < 0)
sysfatal("pipe: %r");
switch(rfork(RFNOWAIT|RFPROC|RFMEM|RFFDG|RFREND)) {
case -1:
fatal("filter: rfork; %r\n");
case 0:
close(fd);
if (dup(p[0], 1) < 0)
fatal("filter: Cannot dup to 1; %r");
if (dup(p[0], 0) < 0)
fatal("filter: Cannot dup to 0; %r");
close(p[0]);
close(p[1]);
exec(file, argv);
fatal("filter: exec; %r");
default:
dup(p[1], fd);
close(p[0]);
close(p[1]);
}
}
static void
mksecret(char *t, uchar *f)
{
sprint(t, "%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux",
f[0], f[1], f[2], f[3], f[4], f[5], f[6], f[7], f[8], f[9]);
}
void
usage(void)
{
fprint(2, "usage: %s [-adnsR] [-f dbgfile] [-m msize] [-r root] "
"[-S srvfile] [-e 'crypt hash'] [-P exclusion-file] "
"[-A announce-string] [-B address]\n", argv0);
fatal("usage");
}
void
main(int argc, char **argv)
{
char buf[ERRMAX], ebuf[ERRMAX], initial[4], *ini, *srvfdfile;
char *dbfile, *srv, *na, *nsfile, *keyspec;
int doauth, n, fd;
AuthInfo *ai;
Fsrpc *r;
dbfile = "/tmp/exportdb";
srv = nil;
srvfd = -1;
srvfdfile = nil;
na = nil;
nsfile = nil;
keyspec = "";
doauth = 0;
ai = nil;
ARGBEGIN{
case 'a':
doauth = 1;
break;
case 'd':
dbg++;
break;
case 'e':
ealgs = EARGF(usage());
if(*ealgs == 0 || strcmp(ealgs, "clear") == 0)
ealgs = nil;
break;
case 'f':
dbfile = EARGF(usage());
break;
case 'k':
keyspec = EARGF(usage());
break;
case 'm':
messagesize = strtoul(EARGF(usage()), nil, 0);
break;
case 'n':
nonone = 0;
break;
case 'r':
srv = EARGF(usage());
break;
case 's':
srv = "/";
break;
case 'A':
anstring = EARGF(usage());
break;
case 'B':
na = EARGF(usage());
break;
case 'F':
/* accepted but ignored, for backwards compatibility */
break;
case 'N':
nsfile = EARGF(usage());
break;
case 'P':
patternfile = EARGF(usage());
break;
case 'R':
readonly = 1;
break;
case 'S':
if(srvfdfile != nil)
usage();
srvfdfile = EARGF(usage());
break;
default:
usage();
}ARGEND
USED(argc, argv);
if(na == nil && doauth){
/*
* We use p9any so we don't have to visit this code again, with the
* cost that this code is incompatible with the old world, which
* requires p9sk2. (The two differ in who talks first, so compatibility
* is awkward.)
*/
ai = auth_proxy(0, auth_getkey, "proto=p9any role=server %s", keyspec);
if(ai == nil)
fatal("auth_proxy: %r");
if(nonone && strcmp(ai->cuid, "none") == 0)
fatal("exportfs by none disallowed");
if(auth_chuid(ai, nsfile) < 0)
fatal("auth_chuid: %r");
else { /* chown network connection */
Dir nd;
nulldir(&nd);
nd.mode = 0660;
nd.uid = ai->cuid;
dirfwstat(0, &nd);
}
putenv("service", "exportfs");
}
if(srvfdfile != nil){
if((srvfd = open(srvfdfile, ORDWR)) < 0)
fatal("open %s: %r", srvfdfile);
}
if(na != nil){
if(srv == nil)
fatal("-B requires -s");
if((fd = dial(netmkaddr(na, 0, "importfs"), 0, 0, 0)) < 0)
fatal("can't dial %s: %r", na);
ai = auth_proxy(fd, auth_getkey, "proto=p9any role=client %s", keyspec);
if(ai == nil)
fatal("%r: %s", na);
dup(fd, 0);
dup(fd, 1);
close(fd);
}
exclusions();
if(dbg) {
n = create(dbfile, OWRITE|OTRUNC, 0666);
dup(n, DFD);
close(n);
}
if(srvfd >= 0 && srv != nil){
fprint(2, "%s: -S cannot be used with -r or -s\n", argv0);
usage();
}
DEBUG(DFD, "%s: started\n", argv0);
rfork(RFNOTEG|RFREND);
if(messagesize == 0){
messagesize = iounit(0);
if(messagesize == 0)
messagesize = 8192+IOHDRSZ;
}
fhash = emallocz(sizeof(Fid*)*FHASHSIZE);
fmtinstall('F', fcallfmt);
/*
* Get tree to serve from network connection,
* check we can get there and ack the connection
*/
if(srvfd != -1) {
/* do nothing */
}
else if(srv != nil) {
if(chdir(srv) < 0) {
ebuf[0] = '\0';
errstr(ebuf, sizeof ebuf);
DEBUG(DFD, "chdir(\"%s\"): %s\n", srv, ebuf);
mounterror(ebuf);
}
DEBUG(DFD, "invoked as server for %s", srv);
strncpy(buf, srv, sizeof buf);
}
else {
buf[0] = 0;
n = read(0, buf, sizeof(buf)-1);
if(n < 0) {
errstr(buf, sizeof buf);
fprint(0, "read(0): %s\n", buf);
DEBUG(DFD, "read(0): %s\n", buf);
exits(buf);
}
buf[n] = 0;
if(chdir(buf) < 0) {
errstr(ebuf, sizeof ebuf);
fprint(0, "chdir(%d:\"%s\"): %s\n", n, buf, ebuf);
DEBUG(DFD, "chdir(%d:\"%s\"): %s\n", n, buf, ebuf);
exits(ebuf);
}
}
DEBUG(DFD, "\niniting root\n");
initroot();
DEBUG(DFD, "%s: %s\n", argv0, buf);
if(srv == nil && srvfd == -1 && write(0, "OK", 2) != 2)
fatal("open ack write");
ini = initial;
n = readn(0, initial, sizeof(initial));
if(n == 0)
fatal(nil); /* port scan or spurious open/close on exported /srv file (unmount) */
if(n < sizeof(initial))
fatal("can't read initial string: %r");
if(memcmp(ini, "impo", 4) == 0) {
char buf[128], *p, *args[3];
ini = nil;
p = buf;
for(;;){
if((n = read(0, p, 1)) < 0)
fatal("can't read impo arguments: %r");
if(n == 0)
fatal("connection closed while reading arguments");
if(*p == '\n')
*p = '\0';
if(*p++ == '\0')
break;
if(p >= buf + sizeof(buf))
fatal("import parameters too long");
}
if(tokenize(buf, args, nelem(args)) != 2)
fatal("impo arguments invalid: impo%s...", buf);
if(strcmp(args[0], "aan") == 0)
filterp = aanfilter;
else if(strcmp(args[0], "nofilter") != 0)
fatal("import filter argument unsupported: %s", args[0]);
if(strcmp(args[1], "ssl") == 0)
encproto = Encssl;
else if(strcmp(args[1], "tls") == 0)
encproto = Enctls;
else if(strcmp(args[1], "clear") != 0)
fatal("import encryption proto unsupported: %s", args[1]);
if(encproto == Enctls)
fatal("%s: tls has not yet been implemented", argv[0]);
}
if(encproto != Encnone && ealgs != nil && ai != nil) {
uchar key[16], digest[SHA1dlen];
char fromclientsecret[21];
char fromserversecret[21];
int i;
if(ai->nsecret < 8)
fatal("secret too small for ssl");
memmove(key+4, ai->secret, 8);
/* exchange random numbers */
srand(truerand());
for(i = 0; i < 4; i++)
key[i+12] = rand();
if(ini != nil)
fatal("Protocol botch: old import");
if(readn(0, key, 4) != 4)
fatal("can't read key part; %r");
if(write(0, key+12, 4) != 4)
fatal("can't write key part; %r");
/* scramble into two secrets */
sha1(key, sizeof(key), digest, nil);
mksecret(fromclientsecret, digest);
mksecret(fromserversecret, digest+10);
if(filterp != nil)
filter(0, filterp, na);
switch(encproto) {
case Encssl:
fd = pushssl(0, ealgs, fromserversecret, fromclientsecret, nil);
if(fd < 0)
fatal("can't establish ssl connection: %r");
if(fd != 0){
dup(fd, 0);
close(fd);
}
break;
case Enctls:
default:
fatal("Unsupported encryption protocol");
}
}
else if(filterp != nil) {
if(ini != nil)
fatal("Protocol botch: don't know how to deal with this");
filter(0, filterp, na);
}
dup(0, 1);
if(ai != nil)
auth_freeAI(ai);
if(ini != nil){
extern void (*fcalls[])(Fsrpc*);
r = getsbuf();
memmove(r->buf, ini, BIT32SZ);
n = GBIT32(r->buf);
if(n <= BIT32SZ || n > messagesize)
fatal("bad length in 9P2000 message header");
n -= BIT32SZ;
if(readn(0, r->buf+BIT32SZ, n) != n)
fatal(nil);
n += BIT32SZ;
if(convM2S(r->buf, n, &r->work) != n)
fatal("convM2S format error");
DEBUG(DFD, "%F\n", &r->work);
(fcalls[r->work.type])(r);
}
io();
}