diff options
Diffstat (limited to 'emu/port/devcap.c')
| -rw-r--r-- | emu/port/devcap.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/emu/port/devcap.c b/emu/port/devcap.c new file mode 100644 index 00000000..00d1c2be --- /dev/null +++ b/emu/port/devcap.c @@ -0,0 +1,243 @@ +#include "dat.h" +#include "fns.h" +#include "error.h" +#include "mp.h" +#include "libsec.h" + +/* + * Copyright © 2003 Vita Nuova Holdings Limited. All rights reserved. + */ + +enum { + Captimeout = 15, /* seconds until expiry */ + Capidletime = 60 /* idle seconds before capwatch exits */ +}; + +typedef struct Caps Caps; +struct Caps +{ + uchar hash[SHA1dlen]; + ulong time; + Caps* next; +}; + +struct { + QLock l; + Caps* caps; + int kpstarted; +} allcaps; + +enum { + Qdir, + Qhash, + Quse +}; + +static Dirtab capdir[] = +{ + ".", {Qdir, 0, QTDIR}, 0, DMDIR|0555, + "capuse", {Quse, 0}, 0, 0222, + "caphash", {Qhash, 0}, 0, 0200, +}; + +static int ncapdir = nelem(capdir); + +static void +capwatch(void *a) +{ + Caps *c, **l; + int idletime; + + USED(a); + idletime = 0; + for(;;){ + osmillisleep(30*1000); + qlock(&allcaps.l); + for(l = &allcaps.caps; (c = *l) != nil;) + if(++c->time > Captimeout){ + *l = c->next; + free(c); + }else + l = &c->next; + if(allcaps.caps == nil){ + if(++idletime > Capidletime){ + allcaps.kpstarted = 0; + qunlock(&allcaps.l); + pexit("", 0); + } + }else + idletime = 0; + qunlock(&allcaps.l); + } +} + +static Chan * +capattach(char *spec) +{ + return devattach(0x00A4, spec); /* L'¤' */ +} + +static Walkqid* +capwalk(Chan *c, Chan *nc, char **name, int nname) +{ + return devwalk(c, nc, name, nname, capdir, nelem(capdir), devgen); +} + +static int +capstat(Chan *c, uchar *db, int n) +{ + return devstat(c, db, n, capdir, nelem(capdir), devgen); +} + +static Chan* +capopen(Chan *c, int omode) +{ + if(c->qid.type & QTDIR) { + if(omode != OREAD) + error(Eisdir); + c->mode = omode; + c->flag |= COPEN; + c->offset = 0; + return c; + } + + if(c->qid.path == Qhash && !iseve()) + error(Eperm); + + c->mode = openmode(omode); + c->flag |= COPEN; + c->offset = 0; + return c; +} + +static void +capclose(Chan *c) +{ + USED(c); +} + +static long +capread(Chan *c, void *va, long n, vlong vl) +{ + USED(vl); + switch((ulong)c->qid.path){ + case Qdir: + return devdirread(c, va, n, capdir, ncapdir, devgen); + + default: + error(Eperm); + break; + } + return n; +} + +static int +capwritehash(uchar *a, int l) +{ + Caps *c; + + if(l != SHA1dlen) + return -1; + c = malloc(sizeof(*c)); + if(c == nil) + return -1; + memmove(c->hash, a, l); + c->time = 0; + qlock(&allcaps.l); + c->next = allcaps.caps; + allcaps.caps = c; + if(!allcaps.kpstarted){ + allcaps.kpstarted = 1; + kproc("capwatch", capwatch, 0, 0); + } + qunlock(&allcaps.l); + return 0; +} + +static int +capwriteuse(uchar *a, int len) +{ + int n; + uchar digest[SHA1dlen]; + char buf[128], *p, *users[3]; + Caps *c, **l; + + if(len >= sizeof(buf)-1) + return -1; + memmove(buf, a, len); + buf[len] = 0; + p = strrchr(buf, '@'); + if(p == nil) + return -1; + *p++ = 0; + len = strlen(p); + n = strlen(buf); + if(len == 0 || n == 0) + return -1; + hmac_sha1((uchar*)buf, n, (uchar*)p, len, digest, nil); + n = getfields(buf, users, nelem(users), 0, "@"); + if(n == 1) + users[1] = users[0]; + else if(n != 2) + return -1; + if(*users[0] == 0 || *users[1] == 0) + return -1; + qlock(&allcaps.l); + for(l = &allcaps.caps; (c = *l) != nil; l = &c->next) + if(memcmp(c->hash, digest, sizeof(c->hash)) == 0){ + *l = c->next; + qunlock(&allcaps.l); + free(c); + if(n == 2 && strcmp(up->env->user, users[0]) != 0) + return -1; + setid(users[1], 0); /* could use users[2] to mean `host OS user' */ + return 0; + } + qunlock(&allcaps.l); + return -1; +} + +static long +capwrite(Chan* c, void* buf, long n, vlong offset) +{ + USED(offset); + switch((ulong)c->qid.path){ + case Qhash: + if(capwritehash(buf, n) < 0) + error(Ebadarg); + return n; + case Quse: + if(capwriteuse(buf, n) < 0) + error("invalid capability"); + return n; + } + error(Ebadarg); + return 0; +} + +static void +capremove(Chan *c) +{ + if(c->qid.path != Qhash || !iseve()) + error(Eperm); + ncapdir = nelem(capdir)-1; +} + +Dev capdevtab = { + 0x00A4, /* L'¤' */ + "cap", + + devinit, + capattach, + capwalk, + capstat, + capopen, + devcreate, + capclose, + capread, + devbread, + capwrite, + devbwrite, + capremove, + devwstat +}; |