ref: dc593372bfc4224c6cf91d2031d0ad0aeadaddfe
dir: /sys/src/cmd/upas/imap4d/mbox.c/
#include "imap4d.h"
static int fsctl = -1;
static char Ecanttalk[] = "can't talk to mail server";
static void
fsinit(void)
{
if(fsctl != -1)
return;
fsctl = open("/mail/fs/ctl", ORDWR);
if(fsctl == -1)
bye(Ecanttalk);
}
static void
boxflags(Box *box)
{
Msg *m;
box->recent = 0;
for(m = box->msgs; m != nil; m = m->next){
if(m->uid == 0){
// fprint(2, "unassigned uid %s\n", m->info[Idigest]);
box->dirtyimp = 1;
m->uid = box->uidnext++;
}
if(m->flags & Frecent)
box->recent++;
}
}
/*
* try to match permissions with mbox
*/
static int
createimp(Box *box, Qid *qid)
{
int fd;
long mode;
Dir *d;
fd = cdcreate(mboxdir, box->imp, OREAD, 0664);
if(fd < 0)
return -1;
d = cddirstat(mboxdir, box->name);
if(d != nil){
mode = d->mode & 0777;
nulldir(d);
d->mode = mode;
dirfwstat(fd, d);
free(d);
}
if(fqid(fd, qid) < 0){
close(fd);
return -1;
}
return fd;
}
/*
* read in the .imp file, or make one if it doesn't exist.
* make sure all flags and uids are consistent.
* return the mailbox lock.
*/
static Mblock*
openimp(Box *box, int new)
{
char buf[ERRMAX];
int fd;
Biobuf b;
Mblock *ml;
Qid qid;
ml = mblock();
if(ml == nil)
return nil;
fd = cdopen(mboxdir, box->imp, OREAD);
if(fd < 0 || fqid(fd, &qid) < 0){
if(fd < 0){
errstr(buf, sizeof buf);
if(cistrstr(buf, "does not exist") == nil)
ilog("imp: %s: %s", box->imp, buf);
else
debuglog("imp: %s: %s .. creating", box->imp, buf);
}else{
close(fd);
ilog("%s: bogus imp: bad qid: recreating", box->imp);
}
fd = createimp(box, &qid);
if(fd < 0){
ilog("createimp fails: %r");
mbunlock(ml);
return nil;
}
box->dirtyimp = 1;
if(box->uidvalidity == 0){
ilog("set uidvalidity %lud [new]\n", box->uidvalidity);
box->uidvalidity = box->mtime;
}
box->impqid = qid;
new = 1;
}else if(qid.path != box->impqid.path || qid.vers != box->impqid.vers){
Binit(&b, fd, OREAD);
if(parseimp(&b, box) == -1){
ilog("%s: bogus imp: parse failure", box->imp);
box->dirtyimp = 1;
if(box->uidvalidity == 0){
ilog("set uidvalidity %lud [parseerr]\n", box->uidvalidity);
box->uidvalidity = box->mtime;
}
}
Bterm(&b);
box->impqid = qid;
new = 1;
}
if(new)
boxflags(box);
close(fd);
return ml;
}
/*
* mailbox is unreachable, so mark all messages expunged
* clean up .imp files as well.
*/
static void
mboxgone(Box *box)
{
char buf[ERRMAX];
Msg *m;
rerrstr(buf, ERRMAX);
if(strstr(buf, "hungup channel"))
bye(Ecanttalk);
// too smart.
// if(cdexists(mboxdir, box->name) < 0)
// cdremove(mboxdir, box->imp);
for(m = box->msgs; m != nil; m = m->next)
m->expunged = 1;
ilog("mboxgone");
box->writable = 0;
}
/*
* read messages in the mailbox
* mark message that no longer exist as expunged
* returns -1 for failure, 0 if no new messages, 1 if new messages.
*/
enum {
Gone = 2, /* don't unexpunge messages */
};
static int
readbox(Box *box)
{
char buf[ERRMAX];
int i, n, fd, new, id;
Dir *d;
Msg *m, *last;
fd = cdopen(box->fsdir, ".", OREAD);
if(fd == -1){
goinggoinggone:
rerrstr(buf, ERRMAX);
ilog("upas/fs stat of %s/%s aka %s failed: %r",
username, box->name, box->fsdir);
mboxgone(box);
return -1;
}
if((d = dirfstat(fd)) == nil){
close(fd);
goto goinggoinggone;
}
box->mtime = d->mtime;
box->qid = d->qid;
last = nil;
for(m = box->msgs; m != nil; m = m->next){
last = m;
m->expunged |= Gone;
}
new = 0;
free(d);
for(;;){
n = dirread(fd, &d);
if(n <= 0){
close(fd);
if(n == -1)
goto goinggoinggone;
break;
}
for(i = 0; i < n; i++){
if((d[i].qid.type & QTDIR) == 0)
continue;
id = atoi(d[i].name);
if(m = fstreefind(box, id)){
m->expunged &= ~Gone;
continue;
}
new = 1;
m = MKZ(Msg);
m->id = id;
m->fsdir = box->fsdir;
m->fs = emalloc(2 * (Filelen + 1));
m->efs = seprint(m->fs, m->fs + (Filelen + 1), "%ud/", id);
m->size = ~0UL;
m->lines = ~0UL;
m->flags = Frecent;
if(!msginfo(m) || m->info[Idigest] == 0)
freemsg(0, m);
else{
fstreeadd(box, m);
if(last == nil)
box->msgs = m;
else
last->next = m;
last = m;
}
}
free(d);
}
/* box->max is invalid here */
return new;
}
int
uidcmp(void *va, void *vb)
{
Msg **a, **b;
a = va;
b = vb;
return (*a)->uid - (*b)->uid;
}
static void
sequence(Box *box)
{
Msg **a, *m;
int n, i;
n = 0;
for(m = box->msgs; m; m = m->next)
n++;
a = ezmalloc(n * sizeof *a);
i = 0;
for(m = box->msgs; m; m = m->next)
a[i++] = m;
qsort(a, n, sizeof *a, uidcmp);
for(i = 0; i < n - 1; i++)
a[i]->next = a[i + 1];
for(i = 0; i < n; i++)
if(a[i]->seq && a[i]->seq != i + 1)
bye("internal error assigning message numbers");
else
a[i]->seq = i + 1;
box->msgs = nil;
if(n > 0){
a[n - 1]->next = nil;
box->msgs = a[0];
}
box->max = n;
memset(a, 0, n*sizeof *a);
free(a);
}
/*
* strategy:
* every mailbox file has an associated .imp file
* which maps upas/fs message digests to uids & message flags.
*
* the .imp files are locked by /mail/fs/usename/L.mbox.
* whenever the flags can be modified, the lock file
* should be opened, thereby locking the uid & flag state.
* for example, whenever new uids are assigned to messages,
* and whenever flags are changed internally, the lock file
* should be open and locked. this means the file must be
* opened during store command, and when changing the \seen
* flag for the fetch command.
*
* if no .imp file exists, a null one must be created before
* assigning uids.
*
* the .imp file has the following format
* imp : "imap internal mailbox description\n"
* uidvalidity " " uidnext "\n"
* messagelines
*
* messagelines :
* | messagelines digest " " uid " " flags "\n"
*
* uid, uidnext, and uidvalidity are 32 bit decimal numbers
* printed right justified in a field Nuid characters long.
* the 0 uid implies that no uid has been assigned to the message,
* but the flags are valid. note that message lines are in mailbox
* order, except possibly for 0 uid messages.
*
* digest is an ascii hex string Ndigest characters long.
*
* flags has a character for each of NFlag flag fields.
* if the flag is clear, it is represented by a "-".
* set flags are represented as a unique single ascii character.
* the currently assigned flags are, in order:
* Fseen s
* Fanswered a
* Fflagged f
* Fdeleted D
* Fdraft d
*/
Box*
openbox(char *name, char *fsname, int writable)
{
char err[ERRMAX];
int new;
Box *box;
Mblock *ml;
fsinit();
if(!strcmp(name, "mbox"))ilog("open %F %q", name, fsname);
if(fprint(fsctl, "open %F %q", name, fsname) < 0){
rerrstr(err, sizeof err);
if(strstr(err, "file does not exist") == nil)
ilog("fs open %F as %s: %s", name, fsname, err);
if(strstr(err, "hungup channel"))
bye(Ecanttalk);
fprint(fsctl, "close %s", fsname);
return nil;
}
/*
* read box to find all messages
* each one has a directory, and is in numerical order
*/
box = MKZ(Box);
box->writable = writable;
box->name = smprint("%s", name);
box->imp = smprint("%s.imp", name);
box->fs = smprint("%s", fsname);
box->fsdir = smprint("/mail/fs/%s", fsname);
box->uidnext = 1;
box->fstree = avlcreate(fstreecmp);
new = readbox(box);
if(new >= 0 && (ml = openimp(box, new))){
closeimp(box, ml);
sequence(box);
return box;
}
closebox(box, 0);
return nil;
}
/*
* careful: called by idle polling proc
*/
Mblock*
checkbox(Box *box, int imped)
{
int new;
Dir *d;
Mblock *ml;
if(box == nil)
return nil;
/*
* if stat fails, mailbox must be gone
*/
d = cddirstat(box->fsdir, ".");
if(d == nil){
mboxgone(box);
return nil;
}
new = 0;
if(box->qid.path != d->qid.path || box->qid.vers != d->qid.vers
|| box->mtime != d->mtime){
new = readbox(box);
if(new < 0){
free(d);
return nil;
}
}
free(d);
ml = openimp(box, new);
if(ml == nil){
ilog("openimp fails; box->writable = 0: %r");
box->writable = 0;
}else if(!imped){
closeimp(box, ml);
ml = nil;
}
if(new || box->dirtyimp)
sequence(box);
return ml;
}
/*
* close the .imp file, after writing out any changes
*/
void
closeimp(Box *box, Mblock *ml)
{
int fd;
Biobuf b;
Qid qid;
if(ml == nil)
return;
if(!box->dirtyimp){
mbunlock(ml);
return;
}
fd = cdcreate(mboxdir, box->imp, OWRITE, 0664);
if(fd < 0){
mbunlock(ml);
return;
}
Binit(&b, fd, OWRITE);
box->dirtyimp = 0;
wrimp(&b, box);
Bterm(&b);
if(fqid(fd, &qid) == 0)
box->impqid = qid;
close(fd);
mbunlock(ml);
}
void
closebox(Box *box, int opened)
{
Msg *m, *next;
/*
* make sure to leave the mailbox directory so upas/fs can close the mailbox
*/
mychdir(mboxdir);
if(box->writable){
deletemsg(box, 0);
if(expungemsgs(box, 0))
closeimp(box, checkbox(box, 1));
}
if(fprint(fsctl, "close %s", box->fs) < 0 && opened)
bye(Ecanttalk);
for(m = box->msgs; m != nil; m = next){
next = m->next;
freemsg(box, m);
}
free(box->name);
free(box->fs);
free(box->fsdir);
free(box->imp);
free(box->fstree);
free(box);
}
int
deletemsg(Box *box, Msgset *ms)
{
char buf[Bufsize], *p, *start;
int ok;
Msg *m;
if(!box->writable)
return 0;
/*
* first pass: delete messages; gang the writes together for speed.
*/
ok = 1;
start = seprint(buf, buf + sizeof buf, "delete %s", box->fs);
p = start;
for(m = box->msgs; m != nil; m = m->next)
if(ms == 0 || ms && inmsgset(ms, m->uid))
if((m->flags & Fdeleted) && !m->expunged){
m->expunged = 1;
p = seprint(p, buf + sizeof buf, " %ud", m->id);
if(p + 32 >= buf + sizeof buf){
if(write(fsctl, buf, p - buf) == -1)
bye(Ecanttalk);
p = start;
}
}
if(p != start && write(fsctl, buf, p - buf) == -1)
bye(Ecanttalk);
return ok;
}
/*
* second pass: remove the message structure,
* and renumber message sequence numbers.
* update messages counts in mailbox.
* returns true if anything changed.
*/
int
expungemsgs(Box *box, int send)
{
uint n;
Msg *m, *next, *last;
n = 0;
last = nil;
for(m = box->msgs; m != nil; m = next){
m->seq -= n;
next = m->next;
if(m->expunged){
if(send)
Bprint(&bout, "* %ud expunge\r\n", m->seq);
if(m->flags & Frecent)
box->recent--;
n++;
if(last == nil)
box->msgs = next;
else
last->next = next;
freemsg(box, m);
}else
last = m;
}
if(n){
box->max -= n;
box->dirtyimp = 1;
}
return n;
}
static char *stoplist[] =
{
".",
"dead.letter",
"forward",
"headers",
"imap.subscribed",
"mbox",
"names",
"pipefrom",
"pipeto",
0
};
/*
* reject bad mailboxes based on mailbox name
*/
int
okmbox(char *path)
{
char *name;
int i, c;
name = strrchr(path, '/');
if(name == nil)
name = path;
else
name++;
if(strlen(name) + STRLEN(".imp") >= Pathlen)
return 0;
for(i = 0; stoplist[i]; i++)
if(strcmp(name, stoplist[i]) == 0)
return 0;
c = name[0];
if(c == 0 || c == '-' || c == '/'
|| isdotdot(name)
|| isprefix("L.", name)
|| isprefix("imap-tmp.", name)
|| issuffix("-", name)
|| issuffix(".00", name)
|| issuffix(".imp", name)
|| issuffix(".idx", name))
return 0;
return 1;
}
int
creatembox(char *mbox)
{
fsinit();
if(fprint(fsctl, "create %q", mbox) > 0){
fprint(fsctl, "close %s", mbox);
return 0;
}
return -1;
}
/*
* rename mailbox. truncaes or removes the source.
* bug? is the lock required
* upas/fs helpfully moves our .imp file.
*/
int
renamebox(char *from, char *to, int doremove)
{
char *p;
int r;
Mblock *ml;
fsinit();
ml = mblock();
if(ml == nil)
return 0;
if(doremove)
r = fprint(fsctl, "rename %F %F", from, to);
else
r = fprint(fsctl, "rename -t %F %F", from, to);
if(r > 0){
if(p = strrchr(to, '/'))
p++;
else
p = to;
fprint(fsctl, "close %s", p);
}
mbunlock(ml);
return r > 0;
}
/*
* upas/fs likes us; he removes the .imp file
*/
int
removembox(char *path)
{
fsinit();
return fprint(fsctl, "remove %s", path) > 0;
}