From 87471918b20957694cb7a7503d2f868c8813c68b Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Mon, 27 Mar 2023 21:25:05 +0300 Subject: [PATCH] Gzip: compatibility with recent zlib-ng versions. It now uses custom alloc_aligned() wrapper for all allocations, therefore all allocations are larger than expected by (64 + sizeof(void*)). Further, they are seen as allocations of 1 element. Relevant calculations were adjusted to reflect this, and state allocation is now protected with a flag to avoid misinterpreting other allocations as the zlib deflate_state allocation. Further, it no longer forces window bits to 13 on compression level 1, so the comment was adjusted to reflect this. --- src/http/modules/ngx_http_gzip_filter_module.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/src/http/modules/ngx_http_gzip_filter_module.c b/src/http/modules/ngx_http_gzip_filter_module.c index b7758690f..ed0de609a 100644 --- a/src/http/modules/ngx_http_gzip_filter_module.c +++ b/src/http/modules/ngx_http_gzip_filter_module.c @@ -57,6 +57,7 @@ typedef struct { unsigned nomem:1; unsigned buffering:1; unsigned zlib_ng:1; + unsigned state_allocated:1; size_t zin; size_t zout; @@ -514,9 +515,10 @@ ngx_http_gzip_filter_memory(ngx_http_request_t *r, ngx_http_gzip_ctx_t *ctx) } else { /* * Another zlib variant, https://github.com/zlib-ng/zlib-ng. - * It forces window bits to 13 for fast compression level, - * uses 16-byte padding in one of window-sized buffers, and - * uses 128K hash. + * It used to force window bits to 13 for fast compression level, + * uses (64 + sizeof(void*)) additional space on all allocations + * for alignment, 16-byte padding in one of window-sized buffers, + * and 128K hash. */ if (conf->level == 1) { @@ -524,7 +526,8 @@ ngx_http_gzip_filter_memory(ngx_http_request_t *r, ngx_http_gzip_ctx_t *ctx) } ctx->allocated = 8192 + 16 + (1 << (wbits + 2)) - + 131072 + (1 << (memlevel + 8)); + + 131072 + (1 << (memlevel + 8)) + + 4 * (64 + sizeof(void*)); ctx->zlib_ng = 1; } } @@ -926,13 +929,16 @@ ngx_http_gzip_filter_alloc(void *opaque, u_int items, u_int size) alloc = items * size; - if (items == 1 && alloc % 512 != 0 && alloc < 8192) { - + if (items == 1 && alloc % 512 != 0 && alloc < 8192 + && !ctx->state_allocated) + { /* * The zlib deflate_state allocation, it takes about 6K, * we allocate 8K. Other allocations are divisible by 512. */ + ctx->state_allocated = 1; + alloc = 8192; }