Download Play: Difference between revisions
| (8 intermediate revisions by the same user not shown) | |||
| Line 8: | Line 8: | ||
UDS [[NWMUDS:Bind|data_channel]] 0x1 is used for spectator data, while all non-spectator data uses data_channel 0x2. The spectator data is received by connecting to the network as a spectator then receiving data-frames, this is handled when scanning for DLP networks. | UDS [[NWMUDS:Bind|data_channel]] 0x1 is used for spectator data, while all non-spectator data uses data_channel 0x2. The spectator data is received by connecting to the network as a spectator then receiving data-frames, this is handled when scanning for DLP networks. | ||
The spectator data includes the 48x48 icon, this has the same format as [[SMDH]]. | |||
This is the data starting at offset 0x0 for UDS PullPacket/SendTo: | This is the data starting at offset 0x0 for UDS PullPacket/SendTo: | ||
| Line 30: | Line 32: | ||
| 0x6 | | 0x6 | ||
| 0x2 | | 0x2 | ||
| | | u16, unknown. For spectator data this is only used for the metadata frame. | ||
|- | |- | ||
| 0x8 | | 0x8 | ||
| Line 57: | Line 59: | ||
|} | |} | ||
Total_frames is at least 0x4 normally. When a sysupdate is included, total_frames is 0x4+<total frames required for the titlelist(normally 0x1)>. | Total_frames is at least 0x4 normally. When a sysupdate is included, total_frames is 0x4+<total frames required for the titlelist(normally 0x1)>. Total_frames should be <=0x20, but the code doesn't check for this specific value. | ||
Frames | ==== Checksum ==== | ||
The checksum seed is the 4-byte output from [[PS:EncryptDecryptAes|encrypting]] zeros with AES-CTR using [[PSPXI:EncryptDecryptAes|keytype5]]. The CTR is the output from this: "for(i=0; i<0x10; i++)ctr[i] = ctrseed[i] ^ host_macaddress[i % 6];" This ctrseed is a fixed 0x10-byte random-data block stored in DLP-sysmodule .rodata. | |||
This seed is initialized after connecting to/creating the DLP network. | |||
The checksum stored in the above data frame header is then calculated using this checksum seed. | |||
First, the calc_checksum is initialized to 0. Then calc_checksum is added with ''all'' words in the data frame loaded as big-endian, with the data-frame checksum cleared to zero here. If the frame_size isn't word-aligned, the remaining <4-bytes are loaded as big-endian for adding as well. | |||
Then this is run: | |||
//During init before the above adding, shift and count are initialized: | |||
//shift = (((u8*)&checksum_seed)[2] & 0xf) + 0x4; | |||
//count = (((u8*)&checksum_seed)[3] & 0x7) + 0x2; | |||
for(pos=0; pos<count; pos++)checksum = (checksum<<shift | checksum>>shift) ^ checksum_seed;//The u32 checksum_seed is byte-swapped on 3DS for this. | |||
Lastly the calculated checksum is written to output as big-endian(hence on 3DS it's byte-swapped before writing to output). | |||
==== Frames ==== | |||
{| class="wikitable" border="1" | {| class="wikitable" border="1" | ||
|- | |- | ||
| Line 68: | Line 86: | ||
| 0x0 | | 0x0 | ||
| 0x300 | | 0x300 | ||
| | | Metadata + start of the icon gfx, see below. | ||
|- | |- | ||
| 0x1-0x3 | | 0x1-0x3 | ||
| Line 81: | Line 99: | ||
The structure of each spectator frame relative to "frame-specific payload" is described below. | The structure of each spectator frame relative to "frame-specific payload" is described below. | ||
==== Metadata frame ==== | ===== Metadata frame ===== | ||
{| class="wikitable" border="1" | {| class="wikitable" border="1" | ||
|- | |- | ||
| Line 89: | Line 107: | ||
|- | |- | ||
| 0x0 | | 0x0 | ||
| | | 0x8 | ||
| | | u64 DLP-child titleID. Must be a CTR TID-high, with the TID-high set for DLP-child. The low 4-bits of the TID-low must be clear. | ||
|- | |- | ||
| 0x8 | | 0x8 | ||
| 0x2 | | 0x2 | ||
| u16, | | u16, probably the DLP-child title-version. | ||
|- | |- | ||
| 0xA | | 0xA | ||
| Line 110: | Line 124: | ||
| 0xC | | 0xC | ||
| 0x4 | | 0x4 | ||
| u32, | | u32, chunk_size. This is the chunk_size used for transferring the CIA. This is the exact size used for the FS .cia file-reads on the host, and the exact size used for [[Application_Manager_Services|AM]] CIA file-writes on the client(s). Normally this is 0x0003FFC0. This appears to be validated by the client at some point, using a large value for this triggers an "connection interrupted" error when trying to connect. | ||
|- | |- | ||
| 0x10 | | 0x10 | ||
| Line 181: | Line 195: | ||
|} | |} | ||
==== Icon gfx frame ==== | If the u16 at frameheader+0x6 is less than 0x101, the 8-bytes at outptr are cleared to all-zero, instead of copying the data from offset 0x2E8. | ||
===== Icon gfx frame ===== | |||
{| class="wikitable" border="1" | {| class="wikitable" border="1" | ||
|- | |- | ||
| Line 193: | Line 209: | ||
|} | |} | ||
==== Sysupdate titlelist frame ==== | ===== Sysupdate titlelist frame ===== | ||
{| class="wikitable" border="1" | {| class="wikitable" border="1" | ||
|- | |- | ||