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u3: distinguish bad backreferences, enforce 62-bit cursors in cue

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This commit is contained in:
Joe Bryan 2020-08-31 17:53:32 -07:00
parent fd5edcb6b6
commit b01d57eb30
1 changed files with 19 additions and 11 deletions
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30
pkg/urbit/noun/serial.c
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@ -923,14 +923,11 @@ _cs_cue_xeno_next(_cue_stack_t* tac_u,
c3_w bak_w;
if ( !ur_dict32_get(rot_u, dic_u, bak_d, &bak_w) ) {
// XX distinguish bad backref?
//
return ur_cue_gone;
}
else {
*out = u3k((u3_noun)bak_w);
return ur_cue_good;
return ur_cue_back;
}
*out = u3k((u3_noun)bak_w);
return ur_cue_good;
}
}
@ -980,8 +977,14 @@ u3s_cue_xeno_unsafe(ur_dict32_t* dic_u,
// init bitstream-reader
//
red_u.left = len_d;
red_u.bytes = byt_y;
if ( ur_cue_good != (res_e = ur_bsr_init(&red_u, len_d, byt_y)) ) {
return res_e;
}
// bit-cursor (and backreferences) must fit in 62-bit direct atoms
//
else if ( 0x7ffffffffffffffULL < len_d ) {
return ur_cue_meme;
}
// setup stack
//
@ -1213,8 +1216,13 @@ u3s_cue_bytes(c3_d len_d, const c3_y* byt_y)
// init bitstream-reader
//
red_u.left = len_d;
red_u.bytes = byt_y;
_cs_cue_need(ur_bsr_init(&red_u, len_d, byt_y));
// bit-cursor (and backreferences) must fit in 62-bit direct atoms
//
if ( 0x7ffffffffffffffULL < len_d ) {
return u3m_bail(c3__meme);
}
// advance into stream
//