ref: c0d21d35b103e980e658fff1ef07107e72a03364
dir: /sys/src/cmd/upas/common/libsys.c/
#include "common.h"
#include <auth.h>
#include <ndb.h>
/*
* return the date
*/
char*
thedate(void)
{
static char now[64];
strcpy(now, ctime(time(0)));
now[28] = 0;
return now;
}
/*
* return the user id of the current user
*/
char *
getlog(void)
{
return getuser();
}
/*
* return the lock name (we use one lock per directory)
*/
static void
lockname(Mlock *l, char *path)
{
char *e, *q;
seprint(l->name, e = l->name+sizeof l->name, "%s", path);
q = strrchr(l->name, '/');
if(q == nil)
q = l->name;
else
q++;
seprint(q, e, "%s", "L.mbox");
}
int
syscreatelocked(char *path, int mode, int perm)
{
return create(path, mode, DMEXCL|perm);
}
int
sysopenlocked(char *path, int mode)
{
/* return open(path, OEXCL|mode);/**/
return open(path, mode); /* until system call is fixed */
}
int
sysunlockfile(int fd)
{
return close(fd);
}
/*
* try opening a lock file. If it doesn't exist try creating it.
*/
static int
openlockfile(Mlock *l)
{
int fd;
Dir *d, nd;
char *p;
l->fd = open(l->name, OREAD);
if(l->fd >= 0)
return 0;
if(d = dirstat(l->name)){
free(d);
return 1; /* try again later */
}
l->fd = create(l->name, OREAD, DMEXCL|0666);
if(l->fd >= 0){
nulldir(&nd);
nd.mode = DMEXCL|0666;
if(dirfwstat(l->fd, &nd) < 0){
/* if we can't chmod, don't bother */
/* live without the lock but log it */
close(l->fd);
l->fd = -1;
syslog(0, "mail", "lock error: %s: %r", l->name);
remove(l->name);
}
return 0;
}
/* couldn't create; let's see what we can whine about */
p = strrchr(l->name, '/');
if(p != 0){
*p = 0;
fd = access(l->name, 2);
*p = '/';
}else
fd = access(".", 2);
if(fd < 0)
/* live without the lock but log it */
syslog(0, "mail", "lock error: %s: %r", l->name);
close(fd);
return 0;
}
#define LSECS 5*60
/*
* Set a lock for a particular file. The lock is a file in the same directory
* and has L. prepended to the name of the last element of the file name.
*/
Mlock*
syslock(char *path)
{
Mlock *l;
int tries;
l = mallocz(sizeof(Mlock), 1);
if(l == 0)
return nil;
lockname(l, path);
/*
* wait LSECS seconds for it to unlock
*/
for(tries = 0; tries < LSECS*2; tries++)
switch(openlockfile(l)){
case 0:
return l;
case 1:
sleep(500);
break;
}
free(l);
return nil;
}
/*
* like lock except don't wait
*/
Mlock *
trylock(char *path)
{
char buf[1];
int fd;
Mlock *l;
l = mallocz(sizeof(Mlock), 1);
if(l == 0)
return 0;
lockname(l, path);
if(openlockfile(l) != 0){
free(l);
return 0;
}
/* fork process to keep lock alive */
switch(l->pid = rfork(RFPROC)){
default:
break;
case 0:
fd = l->fd;
for(;;){
sleep(1000*60);
if(pread(fd, buf, 1, 0) < 0)
break;
}
_exits(nil);
}
return l;
}
void
syslockrefresh(Mlock *l)
{
char buf[1];
pread(l->fd, buf, 1, 0);
}
void
sysunlock(Mlock *l)
{
if(l == 0)
return;
close(l->fd);
if(l->pid > 0)
postnote(PNPROC, l->pid, "time to die");
free(l);
}
/*
* Open a file. The modes are:
*
* l - locked
* a - set append permissions
* r - readable
* w - writable
* A - append only (doesn't exist in Bio)
*/
Biobuf*
sysopen(char *path, char *mode, ulong perm)
{
int sysperm, sysmode, fd, docreate, append, truncate;
Dir *d, nd;
Biobuf *bp;
/*
* decode the request
*/
sysperm = 0;
sysmode = -1;
docreate = 0;
append = 0;
truncate = 0;
for(; *mode; mode++)
switch(*mode){
case 'A':
sysmode = OWRITE;
append = 1;
break;
case 'c':
docreate = 1;
break;
case 'l':
sysperm |= DMEXCL;
break;
case 'a':
sysperm |= DMAPPEND;
break;
case 'w':
if(sysmode == -1)
sysmode = OWRITE;
else
sysmode = ORDWR;
break;
case 'r':
if(sysmode == -1)
sysmode = OREAD;
else
sysmode = ORDWR;
break;
case 't':
truncate = 1;
break;
default:
break;
}
switch(sysmode){
case OREAD:
case OWRITE:
case ORDWR:
break;
default:
if(sysperm&DMAPPEND)
sysmode = OWRITE;
else
sysmode = OREAD;
break;
}
/*
* create file if we need to
*/
if(truncate)
sysmode |= OTRUNC;
fd = open(path, sysmode);
if(fd < 0){
d = dirstat(path);
if(d == nil){
if(docreate == 0)
return 0;
fd = create(path, sysmode, sysperm|perm);
if(fd < 0)
return 0;
nulldir(&nd);
nd.mode = sysperm|perm;
dirfwstat(fd, &nd);
} else {
free(d);
return 0;
}
}
bp = (Biobuf*)malloc(sizeof(Biobuf));
if(bp == 0){
close(fd);
return 0;
}
memset(bp, 0, sizeof(Biobuf));
Binit(bp, fd, sysmode&~OTRUNC);
if(append)
Bseek(bp, 0, 2);
return bp;
}
/*
* close the file, etc.
*/
int
sysclose(Biobuf *bp)
{
int rv;
rv = Bterm(bp);
close(Bfildes(bp));
free(bp);
return rv;
}
/*
* make a directory
*/
int
sysmkdir(char *file, ulong perm)
{
int fd;
if((fd = create(file, OREAD, DMDIR|perm)) < 0)
return -1;
close(fd);
return 0;
}
/*
* read in the system name
*/
char *
sysname_read(void)
{
static char name[128];
char *s, *c;
c = s = getenv("site");
if(!c)
c = alt_sysname_read();
if(!c)
c = "kremvax";
strecpy(name, name+sizeof name, c);
free(s);
return name;
}
char *
alt_sysname_read(void)
{
return sysname();
}
/*
* get all names
*/
char**
sysnames_read(void)
{
int n;
Ndbtuple *t, *nt;
static char **namev;
if(namev)
return namev;
free(csgetvalue(0, "sys", sysname(), "dom", &t));
n = 0;
for(nt = t; nt; nt = nt->entry)
if(strcmp(nt->attr, "dom") == 0)
n++;
namev = (char**)malloc(sizeof(char *)*(n+3));
if(namev){
namev[0] = strdup(sysname_read());
namev[1] = strdup(alt_sysname_read());
n = 2;
for(nt = t; nt; nt = nt->entry)
if(strcmp(nt->attr, "dom") == 0)
namev[n++] = strdup(nt->val);
namev[n] = 0;
}
if(t)
ndbfree(t);
return namev;
}
/*
* read in the domain name
*/
char*
domainname_read(void)
{
char **p;
for(p = sysnames_read(); *p; p++)
if(strchr(*p, '.'))
return *p;
return 0;
}
/*
* rename a file, fails unless both are in the same directory
*/
int
sysrename(char *old, char *new)
{
Dir d;
char *obase;
char *nbase;
obase = strrchr(old, '/');
nbase = strrchr(new, '/');
if(obase){
if(nbase == 0)
return -1;
if(strncmp(old, new, obase-old) != 0)
return -1;
nbase++;
} else {
if(nbase)
return -1;
nbase = new;
}
nulldir(&d);
d.name = nbase;
return dirwstat(old, &d);
}
int
sysexist(char *file)
{
return access(file, AEXIST) == 0;
}
static char yankeepig[] = "die: yankee pig dog";
int
syskill(int pid)
{
return postnote(PNPROC, pid, yankeepig);
}
int
syskillpg(int pid)
{
return postnote(PNGROUP, pid, yankeepig);
}
int
sysdetach(void)
{
if(rfork(RFENVG|RFNAMEG|RFNOTEG) < 0) {
werrstr("rfork failed");
return -1;
}
return 0;
}
/*
* catch a write on a closed pipe
*/
static int *closedflag;
static int
catchpipe(void *, char *msg)
{
static char *foo = "sys: write on closed pipe";
if(strncmp(msg, foo, strlen(foo)) == 0){
if(closedflag)
*closedflag = 1;
return 1;
}
return 0;
}
void
pipesig(int *flagp)
{
closedflag = flagp;
atnotify(catchpipe, 1);
}
void
pipesigoff(void)
{
atnotify(catchpipe, 0);
}
int
islikeatty(int fd)
{
char buf[64];
int l;
if(fd2path(fd, buf, sizeof buf) != 0)
return 0;
/* might be /mnt/term/dev/cons */
l = strlen(buf);
return l >= 9 && strcmp(buf+l-9, "/dev/cons") == 0;
}
int
holdon(void)
{
int fd;
if(!islikeatty(0))
return -1;
fd = open("/dev/consctl", OWRITE);
write(fd, "holdon", 6);
return fd;
}
int
sysopentty(void)
{
return open("/dev/cons", ORDWR);
}
void
holdoff(int fd)
{
write(fd, "holdoff", 7);
close(fd);
}
int
sysfiles(void)
{
return 128;
}
/*
* expand a path relative to the user's mailbox directory
*
* if the path starts with / or ./, don't change it
*
*/
char*
mboxpathbuf(char *to, int n, char *user, char *path)
{
if(*path == '/' || !strncmp(path, "./", 2) || !strncmp(path, "../", 3))
snprint(to, n, "%s", path);
else
snprint(to, n, "%s/box/%s/%s", MAILROOT, user, path);
return to;
}
/*
* warning: we're not quoting bad characters. we're not encoding
* non-ascii characters. basically this function sucks. don't use.
*/
char*
username0(Biobuf *b, char *from)
{
char *p, *f[6];
int n;
static char buf[32];
n = strlen(from);
buf[0] = 0;
for(;; free(p)) {
p = Brdstr(b, '\n', 1);
if(p == 0)
break;
if(strncmp(p, from, n) || p[n] != '|')
continue;
if(getfields(p, f, nelem(f), 0, "|") < 3)
continue;
snprint(buf, sizeof buf, "\"%s\"", f[2]);
/* no break; last match wins */
}
return buf[0]? buf: 0;
}
char*
username(char *from)
{
char *s;
Biobuf *b;
s = 0;
if(b = Bopen("/adm/keys.who", OREAD)){
s = username0(b, from);
Bterm(b);
}
if(s == 0 && (b = Bopen("/adm/netkeys.who", OREAD))){
s = username0(b, from);
Bterm(b);
}
return s;
}
/*
* create a file and
* 1) ensure the modes we asked for
* 2) make gid == uid
*/
static int
docreate(char *file, int perm)
{
int fd;
Dir ndir;
Dir *d;
/* create the mbox */
fd = create(file, OREAD, perm);
if(fd < 0){
fprint(2, "couldn't create %s\n", file);
return -1;
}
d = dirfstat(fd);
if(d == nil){
fprint(2, "couldn't stat %s\n", file);
return -1;
}
nulldir(&ndir);
ndir.mode = perm;
ndir.gid = d->uid;
if(dirfwstat(fd, &ndir) < 0)
fprint(2, "couldn't chmod %s: %r\n", file);
close(fd);
return 0;
}
static int
createfolder0(char *user, char *folder, char *ftype)
{
char *p, *s, buf[Pathlen];
int isdir, mode;
Dir *d;
assert(folder != 0);
mboxpathbuf(buf, sizeof buf, user, folder);
if(access(buf, 0) == 0){
fprint(2, "%s already exists\n", ftype);
return -1;
}
fprint(2, "creating new %s: %s\n", ftype, buf);
/*
* if we can deliver to this mbox, it needs
* to be read/execable all the way down
*/
mode = 0711;
if(!strncmp(buf, "/mail/box/", 10))
if((s = strrchr(buf, '/')) && !strcmp(s+1, "mbox"))
mode = 0755;
for(p = buf; p; p++) {
if(*p == '/')
continue;
p = strchr(p, '/');
if(p == 0)
break;
*p = 0;
if(access(buf, 0) != 0)
if(docreate(buf, DMDIR|mode) < 0)
return -1;
*p = '/';
}
/* must match folder.c:/^openfolder */
isdir = create(buf, OREAD, DMDIR|0777);
/*
* make sure everyone can write here if it's a mailbox
* rather than a folder
*/
if(mode == 0755)
if(isdir >= 0 && (d = dirfstat(isdir))){
d->mode |= 0773;
dirfwstat(isdir, d);
free(d);
}
if(isdir == -1){
fprint(2, "can't create %s: %s\n", ftype, buf);
return -1;
}
close(isdir);
return 0;
}
int
createfolder(char *user, char *folder)
{
return createfolder0(user, folder, "folder");
}
int
creatembox(char *user, char *mbox)
{
char buf[Pathlen];
if(mbox == 0)
snprint(buf, sizeof buf, "mbox");
else
snprint(buf, sizeof buf, "%s/mbox", mbox);
return createfolder0(user, buf, "mbox");
}