ref: 47ec5de29e56c4cf223e0582b930b88ca2a589ee
dir: /sys/src/cmd/cpu.c/
/*
* cpu.c - Make a connection to a cpu server
*
* Invoked by listen as 'cpu -R | -N service net netdir'
* by users as 'cpu [-h system] [-c cmd args ...]'
*/
#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include <libsec.h>
#define Maxfdata 8192
#define MaxStr 128
void remoteside(void);
void fatal(char*, ...);
void lclnoteproc(int);
void rmtnoteproc(void);
void catcher(void*, char*);
void usage(void);
void writestr(int, char*, char*, int);
int readstr(int, char*, int);
char *rexcall(int*, char*, char*);
int setamalg(char*);
char *keyspec = "";
int notechan;
int exportpid;
char *system;
int cflag;
int nflag;
int dbg;
char *user;
char *patternfile;
char *origargs;
char *srvname = "ncpu";
char *exportfs = "/bin/exportfs";
char *ealgs = "rc4_256 sha1";
/* message size for exportfs; may be larger so we can do big graphics in CPU window */
int msgsize = Maxfdata+IOHDRSZ;
/* encryption mechanisms */
static int clear(int);
int (*encryption)(int) = clear;
/* authentication mechanisms */
static int netkeyauth(int);
static int netkeysrvauth(int, char*);
static int p9auth(int);
static int srvp9auth(int, char*);
static int noauth(int);
static int srvnoauth(int, char*);
typedef struct AuthMethod AuthMethod;
struct AuthMethod {
char *name; /* name of method */
int (*cf)(int); /* client side authentication */
int (*sf)(int, char*); /* server side authentication */
} authmethod[] = {
{ "p9", p9auth, srvp9auth,},
{ "netkey", netkeyauth, netkeysrvauth,},
{ "none", noauth, srvnoauth,},
{ nil, nil}
};
AuthMethod *am = authmethod; /* default is p9 */
int setam(char*);
char *aan = "/bin/aan";
char *anstring = "tcp!*!0";
char *filterp = nil;
int filter(int fd, char *host);
void
usage(void)
{
fprint(2, "usage: cpu [-p] [-h system] [-u user] [-a authmethod] "
"[-e 'crypt hash'] [-k keypattern] [-P patternfile] "
"[-c cmd arg ...]\n");
exits("usage");
}
/*
* reading /proc/pid/args yields either "name args" or "name [display args]",
* so return only args or display args.
*/
static char *
procgetname(void)
{
int fd, n;
char *lp, *rp;
char buf[256];
snprint(buf, sizeof buf, "#p/%d/args", getpid());
if((fd = open(buf, OREAD)) < 0)
return strdup("");
*buf = '\0';
n = read(fd, buf, sizeof buf-1);
close(fd);
if (n >= 0)
buf[n] = '\0';
if ((lp = strchr(buf, '[')) == nil || (rp = strrchr(buf, ']')) == nil) {
lp = strchr(buf, ' ');
if (lp == nil)
return strdup("");
else
return strdup(lp+1);
}
*rp = '\0';
return strdup(lp+1);
}
void
main(int argc, char **argv)
{
char dat[MaxStr], buf[MaxStr], cmd[MaxStr], *p, *s, *err;
int ac, fd, ms, data;
char *av[10];
quotefmtinstall();
origargs = procgetname();
/* see if we should use a larger message size */
fd = open("/dev/draw", OREAD);
if(fd >= 0){
ms = iounit(fd);
if(msgsize < ms+IOHDRSZ)
msgsize = ms+IOHDRSZ;
close(fd);
}
user = getuser();
if(user == nil)
fatal("can't read user name: %r");
ARGBEGIN{
case 'a':
p = EARGF(usage());
if(setam(p) < 0)
fatal("unknown auth method %s", p);
break;
case 'e':
ealgs = EARGF(usage());
if(*ealgs == 0 || strcmp(ealgs, "clear") == 0)
ealgs = nil;
break;
case 'd':
dbg++;
break;
case 'f':
/* ignored but accepted for compatibility */
break;
case 'n':
/* must be specified before -R/-O */
nflag++;
break;
case 'A':
anstring = EARGF(usage());
break;
case 'R': /* From listen */
remoteside();
break;
case 'h':
system = EARGF(usage());
break;
case 'c':
cflag++;
s = cmd;
*s++ = '!';
*s = 0;
while(p = ARGF())
s = seprint(s, cmd+sizeof(cmd), " %q", p);
break;
case 'k':
keyspec = smprint("%s %s", keyspec, EARGF(usage()));
break;
case 'P':
patternfile = EARGF(usage());
break;
case 'u':
user = EARGF(usage());
keyspec = smprint("%s user=%s", keyspec, user);
break;
case 'p':
filterp = aan;
break;
default:
usage();
}ARGEND;
if(argc != 0)
usage();
if(system == nil) {
p = getenv("cpu");
if(p == 0)
fatal("set $cpu");
system = p;
}
if(err = rexcall(&data, system, srvname))
fatal("%s: %s: %r", err, system);
procsetname("%s", origargs);
/* Tell the remote side the command to execute and where our working directory is */
if(cflag)
writestr(data, cmd, "command", 0);
if(getwd(dat, sizeof(dat)) == 0)
writestr(data, "NO", "dir", 0);
else
writestr(data, dat, "dir", 0);
/* start up a process to pass along notes */
lclnoteproc(data);
/*
* Wait for the other end to execute and start our file service
* of /mnt/term
*/
if(readstr(data, buf, sizeof(buf)) < 0)
fatal("waiting for FS: %r");
if(strncmp("FS", buf, 2) != 0) {
print("remote cpu: %s", buf);
exits(buf);
}
/* Begin serving the gnot namespace */
close(0);
dup(data, 0);
close(data);
sprint(buf, "%d", msgsize);
ac = 0;
av[ac++] = exportfs;
av[ac++] = "-m";
av[ac++] = buf;
if(dbg)
av[ac++] = "-d";
if(patternfile != nil){
av[ac++] = "-P";
av[ac++] = patternfile;
}
av[ac] = nil;
exec(exportfs, av);
fatal("starting exportfs: %r");
}
void
fatal(char *fmt, ...)
{
char buf[1024];
va_list arg;
va_start(arg, fmt);
vsnprint(buf, sizeof(buf), fmt, arg);
va_end(arg);
fprint(2, "cpu: %s\n", buf);
syslog(0, "cpu", "%s", buf);
exits(buf);
}
char *negstr = "negotiating authentication method";
/* Invoked with stdin and stdout connected to the network connection */
void
remoteside(void)
{
char user[MaxStr], buf[MaxStr], xdir[MaxStr], cmd[MaxStr];
int i, n, fd, badchdir, gotcmd;
rfork(RFENVG);
putenv("service", "cpu");
fd = 0;
/* negotiate authentication mechanism */
n = readstr(fd, cmd, sizeof(cmd));
if(n < 0)
fatal("authenticating: %r");
filterp = nil;
if(strcmp(cmd, "aan") == 0){
filterp = aan;
writestr(fd, "", nil, 1);
n = readstr(fd, cmd, sizeof(cmd));
if(n < 0)
fatal("authenticating: %r");
}
if(setamalg(cmd) < 0 || (nflag == 0 && am->sf == srvnoauth)) {
writestr(fd, "unsupported auth method", nil, 0);
fatal("bad auth method %s", cmd);
} else
writestr(fd, "", "", 1);
if((fd = (*am->sf)(fd, user)) < 0)
fatal("srvauth: %r");
if((fd = filter(fd, nil)) < 0)
fatal("filter: %r");
if((fd = encryption(fd)) < 0)
fatal("encrypt: %r");
/* Now collect invoking cpu's current directory or possibly a command */
gotcmd = 0;
if(readstr(fd, xdir, sizeof(xdir)) < 0)
fatal("dir/cmd: %r");
if(xdir[0] == '!') {
strcpy(cmd, &xdir[1]);
gotcmd = 1;
if(readstr(fd, xdir, sizeof(xdir)) < 0)
fatal("dir: %r");
}
/* Establish the new process at the current working directory of the gnot */
badchdir = 0;
if(strcmp(xdir, "NO") != 0)
if(chdir(xdir) < 0)
badchdir = 1;
/* Start the gnot serving its namespace */
writestr(fd, "FS", "FS", 0);
writestr(fd, "/", "exportfs dir", 0);
n = read(fd, buf, sizeof(buf));
if(n != 2 || buf[0] != 'O' || buf[1] != 'K')
exits("remote tree");
/* make sure buffers are big by doing fversion explicitly; pick a huge number; other side will trim */
strcpy(buf, VERSION9P);
if(fversion(fd, 64*1024, buf, sizeof buf) < 0)
exits("fversion failed");
if(mount(fd, -1, "/mnt/term", MCREATE|MREPL, "") < 0)
exits("mount failed");
close(fd);
/* the remote noteproc uses the mount so it must follow it */
rmtnoteproc();
for(i = 0; i < 3; i++)
close(i);
if(open("/mnt/term/dev/cons", OREAD) != 0)
exits("open stdin");
if(open("/mnt/term/dev/cons", OWRITE) != 1)
exits("open stdout");
dup(1, 2);
if(badchdir)
print("cpu: failed to chdir to '%s'\n", xdir);
if(gotcmd)
execl("/bin/rc", "rc", "-lc", cmd, nil);
else
execl("/bin/rc", "rc", "-li", nil);
fatal("exec shell: %r");
}
char*
rexcall(int *fd, char *host, char *service)
{
char *na;
char err[ERRMAX];
char msg[MaxStr];
int n;
na = netmkaddr(host, 0, service);
procsetname("dialing %s", na);
if((*fd = dial(na, 0, 0, 0)) < 0)
return "can't dial";
/* negotiate aan filter extension */
if(filterp == aan){
writestr(*fd, "aan", "negotiating aan", 0);
n = readstr(*fd, err, sizeof err);
if(n < 0)
return "negotiating aan";
if(*err){
errstr(err, sizeof err);
return negstr;
}
}
/* negotiate authentication mechanism */
if(ealgs != nil)
snprint(msg, sizeof(msg), "%s %s", am->name, ealgs);
else
snprint(msg, sizeof(msg), "%s", am->name);
procsetname("writing %s", msg);
writestr(*fd, msg, negstr, 0);
procsetname("awaiting auth method");
n = readstr(*fd, err, sizeof err);
if(n < 0)
return negstr;
if(*err){
errstr(err, sizeof err);
return negstr;
}
/* authenticate */
procsetname("%s: auth via %s", origargs, am->name);
if((*fd = (*am->cf)(*fd)) < 0)
return "can't authenticate";
if((*fd = filter(*fd, system)) < 0)
return "can't filter";
if((*fd = encryption(*fd)) < 0)
return "can't encrypt";
return nil;
}
void
writestr(int fd, char *str, char *thing, int ignore)
{
int l, n;
l = strlen(str);
n = write(fd, str, l+1);
if(!ignore && n < 0)
fatal("writing network: %s: %r", thing);
}
int
readstr(int fd, char *str, int len)
{
int n;
while(len) {
n = read(fd, str, 1);
if(n < 0)
return -1;
if(*str == '\0')
return 0;
str++;
len--;
}
return -1;
}
static int
readln(char *buf, int n)
{
int i;
char *p;
n--; /* room for \0 */
p = buf;
for(i=0; i<n; i++){
if(read(0, p, 1) != 1)
break;
if(*p == '\n' || *p == '\r')
break;
p++;
}
*p = '\0';
return p-buf;
}
/*
* user level challenge/response
*/
static int
netkeyauth(int fd)
{
char chall[32];
char resp[32];
strecpy(chall, chall+sizeof chall, getuser());
print("user[%s]: ", chall);
if(readln(resp, sizeof(resp)) < 0)
return -1;
if(*resp != 0)
strcpy(chall, resp);
writestr(fd, chall, "challenge/response", 1);
for(;;){
if(readstr(fd, chall, sizeof chall) < 0)
break;
if(*chall == 0)
return fd;
print("challenge: %s\nresponse: ", chall);
if(readln(resp, sizeof(resp)) < 0)
break;
writestr(fd, resp, "challenge/response", 1);
}
return -1;
}
static int
netkeysrvauth(int fd, char *user)
{
char response[32];
Chalstate *ch;
int tries;
AuthInfo *ai;
if(readstr(fd, user, MaxStr) < 0)
return -1;
ai = nil;
ch = nil;
for(tries = 0; tries < 10; tries++){
if((ch = auth_challenge("proto=p9cr role=server user=%q", user)) == nil)
return -1;
writestr(fd, ch->chal, "challenge", 1);
if(readstr(fd, response, sizeof response) < 0)
return -1;
ch->resp = response;
ch->nresp = strlen(response);
if((ai = auth_response(ch)) != nil)
break;
}
auth_freechal(ch);
if(ai == nil)
return -1;
writestr(fd, "", "challenge", 1);
if(auth_chuid(ai, 0) < 0)
fatal("newns: %r");
auth_freeAI(ai);
return fd;
}
static int
clear(int fd)
{
return fd;
}
static char sslsecret[2][21];
static int
sslencrypt(int fd)
{
return pushssl(fd, ealgs, sslsecret[0], sslsecret[1], nil);
}
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]);
}
static int
sslsetup(int fd, uchar *secret, int nsecret, int isclient)
{
uchar key[16], digest[SHA1dlen];
int i;
if(ealgs == nil)
return fd;
if(nsecret < 8){
werrstr("secret too small to ssl");
return -1;
}
memmove(key+4, secret, 8);
/* exchange random numbers */
srand(truerand());
if(isclient){
for(i = 0; i < 4; i++)
key[i] = rand();
if(write(fd, key, 4) != 4)
return -1;
if(readn(fd, key+12, 4) != 4)
return -1;
} else {
for(i = 0; i < 4; i++)
key[i+12] = rand();
if(readn(fd, key, 4) != 4)
return -1;
if(write(fd, key+12, 4) != 4)
return -1;
}
/* scramble into two secrets */
sha1(key, sizeof(key), digest, nil);
mksecret(sslsecret[isclient == 0], digest);
mksecret(sslsecret[isclient != 0], digest+10);
encryption = sslencrypt;
return fd;
}
/*
* plan9 authentication followed by rc4 encryption
*/
static int
p9auth(int fd)
{
AuthInfo *ai;
ai = auth_proxy(fd, auth_getkey, "proto=p9any role=client %s", keyspec);
if(ai == nil)
return -1;
fd = sslsetup(fd, ai->secret, ai->nsecret, 1);
auth_freeAI(ai);
return fd;
}
static int
noauth(int fd)
{
ealgs = nil;
return fd;
}
static int
srvnoauth(int fd, char *user)
{
strecpy(user, user+MaxStr, getuser());
ealgs = nil;
newns(user, nil);
return fd;
}
static int
srvp9auth(int fd, char *user)
{
AuthInfo *ai;
ai = auth_proxy(fd, nil, "proto=p9any role=server %s", keyspec);
if(ai == nil)
return -1;
if(auth_chuid(ai, nil) < 0)
fatal("newns: %r");
snprint(user, MaxStr, "%s", ai->cuid);
fd = sslsetup(fd, ai->secret, ai->nsecret, 0);
auth_freeAI(ai);
return fd;
}
/*
* set authentication mechanism
*/
int
setam(char *name)
{
for(am = authmethod; am->name != nil; am++)
if(strcmp(am->name, name) == 0)
return 0;
am = authmethod;
return -1;
}
/*
* set authentication mechanism and encryption/hash algs
*/
int
setamalg(char *s)
{
ealgs = strchr(s, ' ');
if(ealgs != nil)
*ealgs++ = 0;
return setam(s);
}
int
filter(int fd, char *host)
{
char addr[128], buf[256], *s, *file, *argv[16];
int p[2], lfd, flags, len, argc;
if(filterp == nil)
return fd;
procsetname("filter %s", filterp);
flags = RFNOWAIT|RFPROC|RFMEM|RFFDG|RFREND;
if(host == nil){
/* remote side */
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'))
len = s - buf;
if(write(fd, buf, len) != len)
fatal("filter: cannot write port; %r");
} else {
/* client side */
flags |= RFNOTEG;
if((len = read(fd, buf, sizeof buf - 1)) < 0)
fatal("filter: cannot read port; %r");
buf[len] = '\0';
if((s = strrchr(buf, '!')) == nil)
fatal("filter: malformed remote port: %s", buf);
strecpy(addr, addr+sizeof(addr), netmkaddr(host, "tcp", s+1));
strecpy(strrchr(addr, '!'), addr+sizeof(addr), s);
}
snprint(buf, sizeof(buf), "%s", filterp);
if((argc = tokenize(buf, argv, nelem(argv)-3)) <= 0)
fatal("filter: empty command");
if(host)
argv[argc++] = "-c";
argv[argc++] = addr;
argv[argc] = nil;
file = argv[0];
if(s = strrchr(argv[0], '/'))
argv[0] = s+1;
if(pipe(p) < 0)
fatal("filter: pipe; %r");
switch(rfork(flags)) {
case -1:
fatal("filter: rfork; %r\n");
case 0:
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:
close(fd);
close(p[0]);
}
return p[1];
}
char *rmtnotefile = "/mnt/term/dev/cpunote";
/*
* loop reading /mnt/term/dev/note looking for notes.
* The child returns to start the shell.
*/
void
rmtnoteproc(void)
{
int n, fd, pid, notepid;
char buf[256];
/* new proc returns to start shell */
pid = rfork(RFPROC|RFFDG|RFNOTEG|RFNAMEG|RFMEM);
switch(pid){
case -1:
syslog(0, "cpu", "cpu -R: can't start noteproc: %r");
return;
case 0:
return;
}
/* new proc reads notes from other side and posts them to shell */
switch(notepid = rfork(RFPROC|RFFDG|RFMEM)){
case -1:
syslog(0, "cpu", "cpu -R: can't start wait proc: %r");
_exits(0);
case 0:
fd = open(rmtnotefile, OREAD);
if(fd < 0)
_exits(0);
for(;;){
n = read(fd, buf, sizeof(buf)-1);
if(n <= 0){
postnote(PNGROUP, pid, "hangup");
_exits(0);
}
buf[n] = 0;
postnote(PNGROUP, pid, buf);
}
}
/* original proc waits for shell proc to die and kills note proc */
for(;;){
n = waitpid();
if(n < 0 || n == pid)
break;
}
postnote(PNPROC, notepid, "kill");
_exits(0);
}
enum
{
Qdir,
Qcpunote,
Nfid = 32,
};
struct {
char *name;
Qid qid;
ulong perm;
} fstab[] =
{
[Qdir] { ".", {Qdir, 0, QTDIR}, DMDIR|0555 },
[Qcpunote] { "cpunote", {Qcpunote, 0}, 0444 },
};
typedef struct Note Note;
struct Note
{
Note *next;
char msg[ERRMAX];
};
typedef struct Request Request;
struct Request
{
Request *next;
Fcall f;
};
typedef struct Fid Fid;
struct Fid
{
int fid;
int file;
int omode;
};
Fid fids[Nfid];
struct {
Lock;
Note *nfirst, *nlast;
Request *rfirst, *rlast;
} nfs;
int
fsreply(int fd, Fcall *f)
{
uchar buf[IOHDRSZ+Maxfdata];
int n;
if(dbg)
fprint(2, "notefs: <-%F\n", f);
n = convS2M(f, buf, sizeof buf);
if(n > 0){
if(write(fd, buf, n) != n){
close(fd);
return -1;
}
}
return 0;
}
/* match a note read request with a note, reply to the request */
int
kick(int fd)
{
Request *rp;
Note *np;
int rv;
for(;;){
lock(&nfs);
rp = nfs.rfirst;
np = nfs.nfirst;
if(rp == nil || np == nil){
unlock(&nfs);
break;
}
nfs.rfirst = rp->next;
nfs.nfirst = np->next;
unlock(&nfs);
rp->f.type = Rread;
rp->f.count = strlen(np->msg);
rp->f.data = np->msg;
rv = fsreply(fd, &rp->f);
free(rp);
free(np);
if(rv < 0)
return -1;
}
return 0;
}
void
flushreq(int tag)
{
Request **l, *rp;
lock(&nfs);
for(l = &nfs.rfirst; *l != nil; l = &(*l)->next){
rp = *l;
if(rp->f.tag == tag){
*l = rp->next;
unlock(&nfs);
free(rp);
return;
}
}
unlock(&nfs);
}
Fid*
getfid(int fid)
{
int i, freefid;
freefid = -1;
for(i = 0; i < Nfid; i++){
if(freefid < 0 && fids[i].file < 0)
freefid = i;
if(fids[i].fid == fid)
return &fids[i];
}
if(freefid >= 0){
fids[freefid].fid = fid;
return &fids[freefid];
}
return nil;
}
int
fsstat(int fd, Fid *fid, Fcall *f)
{
Dir d;
uchar statbuf[256];
memset(&d, 0, sizeof(d));
d.name = fstab[fid->file].name;
d.uid = user;
d.gid = user;
d.muid = user;
d.qid = fstab[fid->file].qid;
d.mode = fstab[fid->file].perm;
d.atime = d.mtime = time(0);
f->stat = statbuf;
f->nstat = convD2M(&d, statbuf, sizeof statbuf);
return fsreply(fd, f);
}
int
fsread(int fd, Fid *fid, Fcall *f)
{
Dir d;
uchar buf[256];
Request *rp;
switch(fid->file){
default:
return -1;
case Qdir:
if(f->offset == 0 && f->count >0){
memset(&d, 0, sizeof(d));
d.name = fstab[Qcpunote].name;
d.uid = user;
d.gid = user;
d.muid = user;
d.qid = fstab[Qcpunote].qid;
d.mode = fstab[Qcpunote].perm;
d.atime = d.mtime = time(0);
f->count = convD2M(&d, buf, sizeof buf);
f->data = (char*)buf;
} else
f->count = 0;
return fsreply(fd, f);
case Qcpunote:
rp = mallocz(sizeof(*rp), 1);
if(rp == nil)
return -1;
rp->f = *f;
lock(&nfs);
if(nfs.rfirst == nil)
nfs.rfirst = rp;
else
nfs.rlast->next = rp;
nfs.rlast = rp;
unlock(&nfs);
return kick(fd);;
}
}
char Eperm[] = "permission denied";
char Enofile[] = "out of files";
char Enotdir[] = "not a directory";
void
notefs(int fd)
{
uchar buf[IOHDRSZ+Maxfdata];
int i, n, ncpunote;
Fcall f;
Qid wqid[MAXWELEM];
Fid *fid, *nfid;
int doreply;
rfork(RFNOTEG);
fmtinstall('F', fcallfmt);
for(n = 0; n < Nfid; n++){
fids[n].file = -1;
fids[n].omode = -1;
}
ncpunote = 0;
for(;;){
n = read9pmsg(fd, buf, sizeof(buf));
if(n <= 0 || convM2S(buf, n, &f) != n)
break;
if(dbg)
fprint(2, "notefs: ->%F\n", &f);
doreply = 1;
fid = getfid(f.fid);
if(fid == nil){
nofids:
f.type = Rerror;
f.ename = Enofile;
fsreply(fd, &f);
continue;
}
switch(f.type++){
default:
f.type = Rerror;
f.ename = "unknown type";
break;
case Tflush:
flushreq(f.oldtag);
break;
case Tversion:
if(f.msize > IOHDRSZ+Maxfdata)
f.msize = IOHDRSZ+Maxfdata;
break;
case Tauth:
f.type = Rerror;
f.ename = "authentication not required";
break;
case Tattach:
f.qid = fstab[Qdir].qid;
fid->file = Qdir;
break;
case Twalk:
nfid = nil;
if(f.newfid != f.fid){
nfid = getfid(f.newfid);
if(nfid == nil)
goto nofids;
nfid->file = fid->file;
fid = nfid;
}
for(i=0; i<f.nwname && i<MAXWELEM; i++){
if(fid->file != Qdir){
f.type = Rerror;
f.ename = Enotdir;
break;
}
if(strcmp(f.wname[i], "..") == 0){
wqid[i] = fstab[Qdir].qid;
continue;
}
if(strcmp(f.wname[i], "cpunote") != 0){
if(i == 0){
f.type = Rerror;
f.ename = "file does not exist";
}
break;
}
fid->file = Qcpunote;
wqid[i] = fstab[Qcpunote].qid;
}
if(nfid != nil && (f.type == Rerror || i < f.nwname))
nfid ->file = -1;
if(f.type != Rerror){
f.nwqid = i;
for(i=0; i<f.nwqid; i++)
f.wqid[i] = wqid[i];
}
break;
case Topen:
if(f.mode != OREAD){
f.type = Rerror;
f.ename = Eperm;
break;
}
fid->omode = f.mode;
if(fid->file == Qcpunote)
ncpunote++;
f.qid = fstab[fid->file].qid;
f.iounit = 0;
break;
case Tread:
if(fsread(fd, fid, &f) < 0)
goto err;
doreply = 0;
break;
case Tclunk:
if(fid->omode != -1 && fid->file == Qcpunote){
ncpunote--;
if(ncpunote == 0) /* remote side is done */
goto err;
}
fid->file = -1;
fid->omode = -1;
break;
case Tstat:
if(fsstat(fd, fid, &f) < 0)
goto err;
doreply = 0;
break;
case Tcreate:
case Twrite:
case Tremove:
case Twstat:
f.type = Rerror;
f.ename = Eperm;
break;
}
if(doreply)
if(fsreply(fd, &f) < 0)
break;
}
err:
if(dbg)
fprint(2, "notefs exiting: %r\n");
werrstr("success");
postnote(PNGROUP, exportpid, "kill");
if(dbg)
fprint(2, "postnote PNGROUP %d: %r\n", exportpid);
close(fd);
}
char notebuf[ERRMAX];
void
catcher(void*, char *text)
{
int n;
n = strlen(text);
if(n >= sizeof(notebuf))
n = sizeof(notebuf)-1;
memmove(notebuf, text, n);
notebuf[n] = '\0';
noted(NCONT);
}
/*
* mount in /dev a note file for the remote side to read.
*/
void
lclnoteproc(int netfd)
{
Waitmsg *w;
Note *np;
int pfd[2];
int pid;
if(pipe(pfd) < 0){
fprint(2, "cpu: can't start note proc: pipe: %r\n");
return;
}
/* new proc mounts and returns to start exportfs */
switch(pid = rfork(RFPROC|RFNAMEG|RFFDG|RFMEM)){
default:
exportpid = pid;
break;
case -1:
fprint(2, "cpu: can't start note proc: rfork: %r\n");
return;
case 0:
close(pfd[0]);
if(mount(pfd[1], -1, "/dev", MBEFORE, "") < 0)
fprint(2, "cpu: can't mount note proc: %r\n");
close(pfd[1]);
return;
}
close(netfd);
close(pfd[1]);
/* new proc listens for note file system rpc's */
switch(rfork(RFPROC|RFNAMEG|RFMEM)){
case -1:
fprint(2, "cpu: can't start note proc: rfork1: %r\n");
_exits(0);
case 0:
notefs(pfd[0]);
_exits(0);
}
/* original proc waits for notes */
notify(catcher);
w = nil;
for(;;) {
*notebuf = 0;
free(w);
w = wait();
if(w == nil) {
if(*notebuf == 0)
break;
np = mallocz(sizeof(Note), 1);
if(np != nil){
strcpy(np->msg, notebuf);
lock(&nfs);
if(nfs.nfirst == nil)
nfs.nfirst = np;
else
nfs.nlast->next = np;
nfs.nlast = np;
unlock(&nfs);
kick(pfd[0]);
}
unlock(&nfs);
} else if(w->pid == exportpid)
break;
}
if(w == nil)
exits(nil);
exits(0);
/* exits(w->msg); */
}