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authorAndrew Clayton <a.clayton@nginx.com>2023-09-14 20:35:15 +0100
committerAndrew Clayton <a.clayton@nginx.com>2023-09-25 13:52:13 +0100
commit0f630c3f604e76de370529907b51ad29dfdc4ecb (patch)
treee7be62ea0201019fb4d69327032f52b5b54c8251 /src/nxt_random.c
parentd5efa5f11f38d4ca6c64374f848055611d4f315c (diff)
downloadunit-0f630c3f604e76de370529907b51ad29dfdc4ecb.tar.gz
unit-0f630c3f604e76de370529907b51ad29dfdc4ecb.tar.bz2
Wasm: Allow uploads larger than 4GiB.
Currently Wasm modules are limited to a 32bit address space (until at least the memory64 work is completed). All the counters etc in the request structure were u32's. Which matched with 32bit memory limitation. However there is really no need to not allow >4GiB uploads that can be saved off to disk or some such. To do this we just need to increase the ->content_len & ->total_content_sent members to u64's. However because we need the request structure to have the exact same layout on 32bit (for Wasm modules) as it does on 64bit we need to re-jig the order of some of these members and add a four-byte padding member. Thus the request structure now looks like on 64bit (as shown by pahole(1)) struct nxt_wasm_request_s { uint32_t method_off; /* 0 4 */ uint32_t method_len; /* 4 4 */ uint32_t version_off; /* 8 4 */ uint32_t version_len; /* 12 4 */ uint32_t path_off; /* 16 4 */ uint32_t path_len; /* 20 4 */ uint32_t query_off; /* 24 4 */ uint32_t query_len; /* 28 4 */ uint32_t remote_off; /* 32 4 */ uint32_t remote_len; /* 36 4 */ uint32_t local_addr_off; /* 40 4 */ uint32_t local_addr_len; /* 44 4 */ uint32_t local_port_off; /* 48 4 */ uint32_t local_port_len; /* 52 4 */ uint32_t server_name_off; /* 56 4 */ uint32_t server_name_len; /* 60 4 */ /* --- cacheline 1 boundary (64 bytes) --- */ uint64_t content_len; /* 64 8 */ uint64_t total_content_sent; /* 72 8 */ uint32_t content_sent; /* 80 4 */ uint32_t content_off; /* 84 4 */ uint32_t request_size; /* 88 4 */ uint32_t nfields; /* 92 4 */ uint32_t tls; /* 96 4 */ char __pad[4]; /* 100 4 */ nxt_wasm_http_field_t fields[]; /* 104 0 */ /* size: 104, cachelines: 2, members: 25 */ /* last cacheline: 40 bytes */ }; and the same structure (taken from unit-wasm) compiled as 32bit struct luw_req { u32 method_off; /* 0 4 */ u32 method_len; /* 4 4 */ u32 version_off; /* 8 4 */ u32 version_len; /* 12 4 */ u32 path_off; /* 16 4 */ u32 path_len; /* 20 4 */ u32 query_off; /* 24 4 */ u32 query_len; /* 28 4 */ u32 remote_off; /* 32 4 */ u32 remote_len; /* 36 4 */ u32 local_addr_off; /* 40 4 */ u32 local_addr_len; /* 44 4 */ u32 local_port_off; /* 48 4 */ u32 local_port_len; /* 52 4 */ u32 server_name_off; /* 56 4 */ u32 server_name_len; /* 60 4 */ /* --- cacheline 1 boundary (64 bytes) --- */ u64 content_len; /* 64 8 */ u64 total_content_sent; /* 72 8 */ u32 content_sent; /* 80 4 */ u32 content_off; /* 84 4 */ u32 request_size; /* 88 4 */ u32 nr_fields; /* 92 4 */ u32 tls; /* 96 4 */ char __pad[4]; /* 100 4 */ struct luw_hdr_field fields[]; /* 104 0 */ /* size: 104, cachelines: 2, members: 25 */ /* last cacheline: 40 bytes */ }; We can see the structures have the same layout, same size and no padding. We need the __pad member as otherwise I saw gcc and clang on Alpine Linux automatically add the 'packed' attribute to the structure which made the two structures not match. Link: <https://github.com/WebAssembly/memory64> Link: <https://github.com/nginx/unit-wasm> Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
Diffstat (limited to 'src/nxt_random.c')
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