diff options
| author | Brian Sipos <brian.sipos@gmail.com> | 2022-10-16 17:30:19 -0400 |
|---|---|---|
| committer | AndersBroman <a.broman58@gmail.com> | 2022-10-19 15:27:42 +0000 |
| commit | 5bb756e203539c7fd3bb6c16dd845e42a347a982 (patch) | |
| tree | 87dca3b98b1766a7fae046bbffc3ec9343dd57fc /epan/tvbuff.c | |
| parent | d2e5bd80cbc5c29f6a33dc6678baeaa4fd358c64 (diff) | |
epan: centralize SDNV processing along other similar varint types
This avoids having general-purpose decoding happening in
non-DLL-exported functions defined in a dissector for #18478,
and removes unused functions and avoids duplicate decoding.
This also removes unnecessary early exit conditions for #18145.
Unit test cases for varint decoding are added to verify this.
Diffstat (limited to 'epan/tvbuff.c')
| -rw-r--r-- | epan/tvbuff.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/epan/tvbuff.c b/epan/tvbuff.c index 81502d2531..97e60b564d 100644 --- a/epan/tvbuff.c +++ b/epan/tvbuff.c @@ -4563,6 +4563,29 @@ tvb_get_varint(tvbuff_t *tvb, guint offset, guint maxlen, guint64 *value, const break; } + case ENC_VARINT_SDNV: + { + /* Decodes similar to protobuf but in MSByte order */ + guint i; + guint64 b; /* current byte */ + + for (i = 0; ((i < FT_VARINT_MAX_LEN) && (i < maxlen)); ++i) { + b = tvb_get_guint8(tvb, offset++); + if ((i == 9) && (*value >= 1ul<<(64-7))) { + // guaranteed overflow, not valid SDNV + return 0; + } + *value <<= 7; + *value |= (b & 0x7F); /* add lower 7 bits to val */ + + if (b < 0x80) { + /* end successfully because of last byte's msb(most significant bit) is zero */ + return i + 1; + } + } + break; + } + case ENC_VARINT_QUIC: { /* calculate variable length */ |