ref: 6ff5c10ffb06d10eee06f1d432f9cc4738496c07
dir: /sys/src/cmd/upas/fs/plan9.c/
#include "common.h" #include <libsec.h> #include "dat.h" typedef struct { Biobuf *in; char *shift; } Inbuf; /* * parse a Unix style header */ static int memtotm(char *p, int n, Tm *t) { char buf[128]; if(n > sizeof buf - 1) n = sizeof buf -1; memcpy(buf, p, n); buf[n] = 0; return strtotm(buf, t); } static int chkunix0(char *s, int n) { char *p; Tm tm; if(n > 256) return -1; if((p = memchr(s, ' ', n)) == nil) return -1; if(memtotm(p, n - (p - s), &tm) < 0) return -1; if(tm2sec(&tm) < 1000000) return -1; return 0; } static int chkunix(char *s, int n) { int r; r = chkunix0(s, n); if(r == -1) eprint("plan9: warning naked from [%.*s]\n", n, s); return r; } static char* parseunix(Message *m) { char *s, *p, *q; int l; Tm tm; l = m->header - m->start; m->unixheader = smprint("%.*s", l, m->start); s = m->start + 5; if((p = strchr(s, ' ')) == nil) return s; *p = 0; m->unixfrom = strdup(s); *p++ = ' '; if(q = strchr(p, '\n')) *q = 0; if(strtotm(p, &tm) < 0) return p; if(q) *q = '\n'; m->fileid = (uvlong)tm2sec(&tm) << 8; return 0; } static void addtomessage(Message *m, char *p, int n) { int i, len; if(n == 0) return; /* add to message (+1 in malloc is for a trailing NUL) */ if(m->lim - m->end < n){ if(m->start != nil){ i = m->end - m->start; len = (4*(i + n))/3; m->start = erealloc(m->start, len + 1); m->end = m->start + i; } else { len = 2*n; m->start = emalloc(len + 1); m->end = m->start; } m->lim = m->start + len; *m->lim = 0; } memmove(m->end, p, n); m->end += n; *m->end = 0; } /* * read in a single message */ static int okmsg(Mailbox *mb, Message *m, Inbuf *b) { char e[ERRMAX], buf[128]; rerrstr(e, sizeof e); if(strlen(e)){ if(fd2path(Bfildes(b->in), buf, sizeof buf) < 0) strcpy(buf, "unknown mailbox"); eprint("plan9: error reading %s: %r\n", buf); return -1; } if(m->end == m->start) return -1; if(m->end[-1] == '\n') m->end--; *m->end = 0; m->size = m->end - m->start; if(m->size >= Maxmsg) return -1; m->bend = m->rbend = m->end; if(m->digest == 0) digestmessage(mb, m); return 0; } static char* inbread(Inbuf *b) { if(b->shift) return b->shift; return b->shift = Brdline(b->in, '\n'); } void inbconsume(Inbuf *b) { b->shift = 0; } /* * bug: very long line with From at the buffer break. */ static int readmessage(Mailbox *mb, Message *m, Inbuf *b) { char *s, *n; long l, state; werrstr(""); state = 0; for(;;){ s = inbread(b); if(s == 0) break; n = s + (l = Blinelen(b->in)) - 1; if(l >= 28 + 7 && n[0] == '\n') if(strncmp(s, "From ", 5) == 0) if(!chkunix(s + 5, l - 5)) if(++state == 2) break; if(state == 0) return -1; addtomessage(m, s, l); inbconsume(b); } return okmsg(mb, m, b); } /* throw out deleted messages. return number of freshly deleted messages */ int purgedeleted(Mailbox *mb) { Message *m, *next; int newdels; /* forget about what's no longer in the mailbox */ newdels = 0; for(m = mb->root->part; m != nil; m = next){ next = m->next; if(m->deleted && m->refs == 0){ if(m->inmbox) newdels++; delmessage(mb, m); } } return newdels; } static void mergemsg(Message *m, Message *x) { assert(m->start == 0); m->mallocd = 1; m->inmbox = 1; m->lim = x->lim; m->start = x->start; m->end = x->end; m->bend = x->bend; m->rbend = x->rbend; x->lim = 0; x->start = 0; x->end = 0; x->bend = 0; x->rbend = 0; } /* * read in the mailbox and parse into messages. */ static char* readmbox(Mailbox *mb, int doplumb, int *new, Mlock *lk) { char *p, *x, buf[Pathlen]; int nnew; Biobuf *in; Dir *d; Inbuf b; Message *m, **l; static char err[ERRMAX]; l = &mb->root->part; /* * open the mailbox. If it doesn't exist, try the temporary one. */ retry: in = Bopen(mb->path, OREAD); if(in == nil){ errstr(err, sizeof(err)); if(strstr(err, "exist") != 0){ snprint(buf, sizeof buf, "%s.tmp", mb->path); if(sysrename(buf, mb->path) == 0) goto retry; } return err; } /* * a new qid.path means reread the mailbox, while * a new qid.vers means read any new messages */ d = dirfstat(Bfildes(in)); if(d == nil){ Bterm(in); errstr(err, sizeof err); return err; } if(mb->d != nil){ if(d->qid.path == mb->d->qid.path && d->qid.vers == mb->d->qid.vers){ *new = 0; Bterm(in); free(d); return nil; } if(d->qid.path == mb->d->qid.path){ while(*l != nil) l = &(*l)->next; Bseek(in, mb->d->length, 0); } free(mb->d); } mb->d = d; memset(&b, 0, sizeof b); b.in = in; b.shift = 0; /* read new messages */ logmsg(nil, "reading %s", mb->path); nnew = 0; for(;;){ if(lk != nil) syslockrefresh(lk); m = newmessage(mb->root); m->mallocd = 1; m->inmbox = 1; if(readmessage(mb, m, &b) < 0){ unnewmessage(mb, mb->root, m); break; } /* merge mailbox versions */ while(*l != nil){ if(memcmp((*l)->digest, m->digest, SHA1dlen) == 0){ if((*l)->start == nil){ logmsg(*l, "read indexed"); mergemsg(*l, m); unnewmessage(mb, mb->root, m); m = *l; }else{ logmsg(*l, "duplicate"); m->inmbox = 1; /* remove it */ unnewmessage(mb, mb->root, m); m = nil; l = &(*l)->next; } break; } else { /* old mail no longer in box, mark deleted */ logmsg(*l, "disappeared"); if(doplumb) mailplumb(mb, *l, 1); (*l)->inmbox = 0; (*l)->deleted = Disappear; l = &(*l)->next; } } if(m == nil) continue; m->header = m->end; if(x = strchr(m->start, '\n')) m->header = x + 1; if(p = parseunix(m)) sysfatal("%s:%lld naked From in body? [%s]", mb->path, seek(Bfildes(in), 0, 1), p); m->mheader = m->mhend = m->header; parse(mb, m, 0, 0); if(m != *l && m->deleted != Dup){ logmsg(m, "new"); newcachehash(mb, m, doplumb); putcache(mb, m); nnew++; } /* chain in */ *l = m; l = &m->next; } logmsg(nil, "mbox read"); /* whatever is left has been removed from the mbox, mark deleted */ while(*l != nil){ if(doplumb) mailplumb(mb, *l, 1); (*l)->inmbox = 0; (*l)->deleted = Deleted; l = &(*l)->next; } Bterm(in); *new = nnew; return nil; } static void writembox(Mailbox *mb, Mlock *lk) { char buf[Pathlen]; int mode, errs; Biobuf *b; Dir *d; Message *m; snprint(buf, sizeof buf, "%s.tmp", mb->path); /* * preserve old files permissions, if possible */ mode = Mboxmode; if(d = dirstat(mb->path)){ mode = d->mode & 0777; free(d); } remove(buf); b = sysopen(buf, "alc", mode); if(b == 0){ eprint("plan9: can't write temporary mailbox %s: %r\n", buf); return; } logmsg(nil, "writing new mbox"); errs = 0; for(m = mb->root->part; m != nil; m = m->next){ if(lk != nil) syslockrefresh(lk); if(m->deleted) continue; logmsg(m, "writing"); if(Bwrite(b, m->start, m->end - m->start) < 0) errs = 1; if(Bwrite(b, "\n", 1) < 0) errs = 1; } logmsg(nil, "wrote new mbox"); if(sysclose(b) < 0) errs = 1; if(errs){ eprint("plan9: error writing temporary mail file\n"); return; } remove(mb->path); if(sysrename(buf, mb->path) < 0) eprint("plan9: can't rename %s to %s: %r\n", buf, mb->path); if(mb->d != nil) free(mb->d); mb->d = dirstat(mb->path); } char* plan9syncmbox(Mailbox *mb, int doplumb, int *new) { char *rv; Mlock *lk; lk = nil; if(mb->dolock){ lk = syslock(mb->path); if(lk == nil) return "can't lock mailbox"; } rv = readmbox(mb, doplumb, new, lk); /* interpolate */ if(purgedeleted(mb) > 0) writembox(mb, lk); if(lk != nil) sysunlock(lk); return rv; } void plan9decache(Mailbox*, Message *m) { m->lim = 0; } /* * look to see if we can open this mail box */ char* plan9mbox(Mailbox *mb, char *path) { char buf[Pathlen]; static char err[Pathlen]; if(access(path, AEXIST) < 0){ errstr(err, sizeof err); snprint(buf, sizeof buf, "%s.tmp", path); if(access(buf, AEXIST) < 0) return err; } mb->sync = plan9syncmbox; mb->remove = localremove; mb->rename = localrename; mb->decache = plan9decache; return nil; }