Mercurial > hg > nginx-quic
view src/core/ngx_slab.c @ 4162:fb1375e8b68c stable-1.0
Merging r4036, r4055, r4056, r4057, r4058, r4059, r4060, r4061, r4062, r4063,
r4064:
Ranges related fixes:
The "max_ranges" directive.
"max_ranges 0" disables ranges support at all,
"max_ranges 1" allows the single range, etc.
By default number of ranges is unlimited, to be precise, 2^31-1.
If client requests more ranges than "max_ranges" permits,
nginx disables ranges and returns just the source response.
If total size of all ranges is greater than source response size,
then nginx disables ranges and returns just the source response.
This fix should not affect well-behaving applications but will defeat
DoS attempts exploiting malicious byte ranges.
Now unsatisfiable ranges are processed according to RFC 2616.
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Fri, 30 Sep 2011 14:06:08 +0000 |
parents | 6b87e875e87a |
children | 1b779cb69dc8 4919fb357a5d |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #define NGX_SLAB_PAGE_MASK 3 #define NGX_SLAB_PAGE 0 #define NGX_SLAB_BIG 1 #define NGX_SLAB_EXACT 2 #define NGX_SLAB_SMALL 3 #if (NGX_PTR_SIZE == 4) #define NGX_SLAB_PAGE_FREE 0 #define NGX_SLAB_PAGE_BUSY 0xffffffff #define NGX_SLAB_PAGE_START 0x80000000 #define NGX_SLAB_SHIFT_MASK 0x0000000f #define NGX_SLAB_MAP_MASK 0xffff0000 #define NGX_SLAB_MAP_SHIFT 16 #define NGX_SLAB_BUSY 0xffffffff #else /* (NGX_PTR_SIZE == 8) */ #define NGX_SLAB_PAGE_FREE 0 #define NGX_SLAB_PAGE_BUSY 0xffffffffffffffff #define NGX_SLAB_PAGE_START 0x8000000000000000 #define NGX_SLAB_SHIFT_MASK 0x000000000000000f #define NGX_SLAB_MAP_MASK 0xffffffff00000000 #define NGX_SLAB_MAP_SHIFT 32 #define NGX_SLAB_BUSY 0xffffffffffffffff #endif #if (NGX_DEBUG_MALLOC) #define ngx_slab_junk(p, size) ngx_memset(p, 0xD0, size) #else #if (NGX_FREEBSD) #define ngx_slab_junk(p, size) \ if (ngx_freebsd_debug_malloc) ngx_memset(p, 0xD0, size) #else #define ngx_slab_junk(p, size) #endif #endif static ngx_slab_page_t *ngx_slab_alloc_pages(ngx_slab_pool_t *pool, ngx_uint_t pages); static void ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page, ngx_uint_t pages); static void ngx_slab_error(ngx_slab_pool_t *pool, ngx_uint_t level, char *text); static ngx_uint_t ngx_slab_max_size; static ngx_uint_t ngx_slab_exact_size; static ngx_uint_t ngx_slab_exact_shift; void ngx_slab_init(ngx_slab_pool_t *pool) { u_char *p; size_t size; ngx_int_t m; ngx_uint_t i, n, pages; ngx_slab_page_t *slots; /* STUB */ if (ngx_slab_max_size == 0) { ngx_slab_max_size = ngx_pagesize / 2; ngx_slab_exact_size = ngx_pagesize / (8 * sizeof(uintptr_t)); for (n = ngx_slab_exact_size; n >>= 1; ngx_slab_exact_shift++) { /* void */ } } /**/ pool->min_size = 1 << pool->min_shift; p = (u_char *) pool + sizeof(ngx_slab_pool_t); size = pool->end - p; ngx_slab_junk(p, size); slots = (ngx_slab_page_t *) p; n = ngx_pagesize_shift - pool->min_shift; for (i = 0; i < n; i++) { slots[i].slab = 0; slots[i].next = &slots[i]; slots[i].prev = 0; } p += n * sizeof(ngx_slab_page_t); pages = (ngx_uint_t) (size / (ngx_pagesize + sizeof(ngx_slab_page_t))); ngx_memzero(p, pages * sizeof(ngx_slab_page_t)); pool->pages = (ngx_slab_page_t *) p; pool->free.prev = 0; pool->free.next = (ngx_slab_page_t *) p; pool->pages->slab = pages; pool->pages->next = &pool->free; pool->pages->prev = (uintptr_t) &pool->free; pool->start = (u_char *) ngx_align_ptr((uintptr_t) p + pages * sizeof(ngx_slab_page_t), ngx_pagesize); m = pages - (pool->end - pool->start) / ngx_pagesize; if (m > 0) { pages -= m; pool->pages->slab = pages; } pool->log_ctx = &pool->zero; pool->zero = '\0'; } void * ngx_slab_alloc(ngx_slab_pool_t *pool, size_t size) { void *p; ngx_shmtx_lock(&pool->mutex); p = ngx_slab_alloc_locked(pool, size); ngx_shmtx_unlock(&pool->mutex); return p; } void * ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size) { size_t s; uintptr_t p, n, m, mask, *bitmap; ngx_uint_t i, slot, shift, map; ngx_slab_page_t *page, *prev, *slots; if (size >= ngx_slab_max_size) { ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab alloc: %uz", size); page = ngx_slab_alloc_pages(pool, (size + ngx_pagesize - 1) >> ngx_pagesize_shift); if (page) { p = (page - pool->pages) << ngx_pagesize_shift; p += (uintptr_t) pool->start; } else { p = 0; } goto done; } if (size > pool->min_size) { shift = 1; for (s = size - 1; s >>= 1; shift++) { /* void */ } slot = shift - pool->min_shift; } else { size = pool->min_size; shift = pool->min_shift; slot = 0; } ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab alloc: %uz slot: %ui", size, slot); slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); page = slots[slot].next; if (page->next != page) { if (shift < ngx_slab_exact_shift) { do { p = (page - pool->pages) << ngx_pagesize_shift; bitmap = (uintptr_t *) (pool->start + p); map = (1 << (ngx_pagesize_shift - shift)) / (sizeof(uintptr_t) * 8); for (n = 0; n < map; n++) { if (bitmap[n] != NGX_SLAB_BUSY) { for (m = 1, i = 0; m; m <<= 1, i++) { if ((bitmap[n] & m)) { continue; } bitmap[n] |= m; i = ((n * sizeof(uintptr_t) * 8) << shift) + (i << shift); if (bitmap[n] == NGX_SLAB_BUSY) { for (n = n + 1; n < map; n++) { if (bitmap[n] != NGX_SLAB_BUSY) { p = (uintptr_t) bitmap + i; goto done; } } prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; page->next = NULL; page->prev = NGX_SLAB_SMALL; } p = (uintptr_t) bitmap + i; goto done; } } } page = page->next; } while (page); } else if (shift == ngx_slab_exact_shift) { do { if (page->slab != NGX_SLAB_BUSY) { for (m = 1, i = 0; m; m <<= 1, i++) { if ((page->slab & m)) { continue; } page->slab |= m; if (page->slab == NGX_SLAB_BUSY) { prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; page->next = NULL; page->prev = NGX_SLAB_EXACT; } p = (page - pool->pages) << ngx_pagesize_shift; p += i << shift; p += (uintptr_t) pool->start; goto done; } } page = page->next; } while (page); } else { /* shift > ngx_slab_exact_shift */ n = ngx_pagesize_shift - (page->slab & NGX_SLAB_SHIFT_MASK); n = 1 << n; n = ((uintptr_t) 1 << n) - 1; mask = n << NGX_SLAB_MAP_SHIFT; do { if ((page->slab & NGX_SLAB_MAP_MASK) != mask) { for (m = (uintptr_t) 1 << NGX_SLAB_MAP_SHIFT, i = 0; m & mask; m <<= 1, i++) { if ((page->slab & m)) { continue; } page->slab |= m; if ((page->slab & NGX_SLAB_MAP_MASK) == mask) { prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; page->next = NULL; page->prev = NGX_SLAB_BIG; } p = (page - pool->pages) << ngx_pagesize_shift; p += i << shift; p += (uintptr_t) pool->start; goto done; } } page = page->next; } while (page); } } page = ngx_slab_alloc_pages(pool, 1); if (page) { if (shift < ngx_slab_exact_shift) { p = (page - pool->pages) << ngx_pagesize_shift; bitmap = (uintptr_t *) (pool->start + p); s = 1 << shift; n = (1 << (ngx_pagesize_shift - shift)) / 8 / s; if (n == 0) { n = 1; } bitmap[0] = (2 << n) - 1; map = (1 << (ngx_pagesize_shift - shift)) / (sizeof(uintptr_t) * 8); for (i = 1; i < map; i++) { bitmap[i] = 0; } page->slab = shift; page->next = &slots[slot]; page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_SMALL; slots[slot].next = page; p = ((page - pool->pages) << ngx_pagesize_shift) + s * n; p += (uintptr_t) pool->start; goto done; } else if (shift == ngx_slab_exact_shift) { page->slab = 1; page->next = &slots[slot]; page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_EXACT; slots[slot].next = page; p = (page - pool->pages) << ngx_pagesize_shift; p += (uintptr_t) pool->start; goto done; } else { /* shift > ngx_slab_exact_shift */ page->slab = ((uintptr_t) 1 << NGX_SLAB_MAP_SHIFT) | shift; page->next = &slots[slot]; page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_BIG; slots[slot].next = page; p = (page - pool->pages) << ngx_pagesize_shift; p += (uintptr_t) pool->start; goto done; } } p = 0; done: ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab alloc: %p", p); return (void *) p; } void ngx_slab_free(ngx_slab_pool_t *pool, void *p) { ngx_shmtx_lock(&pool->mutex); ngx_slab_free_locked(pool, p); ngx_shmtx_unlock(&pool->mutex); } void ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p) { size_t size; uintptr_t slab, m, *bitmap; ngx_uint_t n, type, slot, shift, map; ngx_slab_page_t *slots, *page; ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab free: %p", p); if ((u_char *) p < pool->start || (u_char *) p > pool->end) { ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_free(): outside of pool"); goto fail; } n = ((u_char *) p - pool->start) >> ngx_pagesize_shift; page = &pool->pages[n]; slab = page->slab; type = page->prev & NGX_SLAB_PAGE_MASK; switch (type) { case NGX_SLAB_SMALL: shift = slab & NGX_SLAB_SHIFT_MASK; size = 1 << shift; if ((uintptr_t) p & (size - 1)) { goto wrong_chunk; } n = ((uintptr_t) p & (ngx_pagesize - 1)) >> shift; m = (uintptr_t) 1 << (n & (sizeof(uintptr_t) * 8 - 1)); n /= (sizeof(uintptr_t) * 8); bitmap = (uintptr_t *) ((uintptr_t) p & ~(ngx_pagesize - 1)); if (bitmap[n] & m) { if (page->next == NULL) { slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); slot = shift - pool->min_shift; page->next = slots[slot].next; slots[slot].next = page; page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_SMALL; page->next->prev = (uintptr_t) page | NGX_SLAB_SMALL; } bitmap[n] &= ~m; n = (1 << (ngx_pagesize_shift - shift)) / 8 / (1 << shift); if (n == 0) { n = 1; } if (bitmap[0] & ~(((uintptr_t) 1 << n) - 1)) { goto done; } map = (1 << (ngx_pagesize_shift - shift)) / (sizeof(uintptr_t) * 8); for (n = 1; n < map; n++) { if (bitmap[n]) { goto done; } } ngx_slab_free_pages(pool, page, 1); goto done; } goto chunk_already_free; case NGX_SLAB_EXACT: m = (uintptr_t) 1 << (((uintptr_t) p & (ngx_pagesize - 1)) >> ngx_slab_exact_shift); size = ngx_slab_exact_size; if ((uintptr_t) p & (size - 1)) { goto wrong_chunk; } if (slab & m) { if (slab == NGX_SLAB_BUSY) { slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); slot = ngx_slab_exact_shift - pool->min_shift; page->next = slots[slot].next; slots[slot].next = page; page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_EXACT; page->next->prev = (uintptr_t) page | NGX_SLAB_EXACT; } page->slab &= ~m; if (page->slab) { goto done; } ngx_slab_free_pages(pool, page, 1); goto done; } goto chunk_already_free; case NGX_SLAB_BIG: shift = slab & NGX_SLAB_SHIFT_MASK; size = 1 << shift; if ((uintptr_t) p & (size - 1)) { goto wrong_chunk; } m = (uintptr_t) 1 << ((((uintptr_t) p & (ngx_pagesize - 1)) >> shift) + NGX_SLAB_MAP_SHIFT); if (slab & m) { if (page->next == NULL) { slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); slot = shift - pool->min_shift; page->next = slots[slot].next; slots[slot].next = page; page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_BIG; page->next->prev = (uintptr_t) page | NGX_SLAB_BIG; } page->slab &= ~m; if (page->slab & NGX_SLAB_MAP_MASK) { goto done; } ngx_slab_free_pages(pool, page, 1); goto done; } goto chunk_already_free; case NGX_SLAB_PAGE: if ((uintptr_t) p & (ngx_pagesize - 1)) { goto wrong_chunk; } if (slab == NGX_SLAB_PAGE_FREE) { ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_free(): page is already free"); goto fail; } if (slab == NGX_SLAB_PAGE_BUSY) { ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_free(): pointer to wrong page"); goto fail; } n = ((u_char *) p - pool->start) >> ngx_pagesize_shift; size = slab & ~NGX_SLAB_PAGE_START; ngx_slab_free_pages(pool, &pool->pages[n], size); ngx_slab_junk(p, size << ngx_pagesize_shift); return; } /* not reached */ return; done: ngx_slab_junk(p, size); return; wrong_chunk: ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_free(): pointer to wrong chunk"); goto fail; chunk_already_free: ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_free(): chunk is already free"); fail: return; } static ngx_slab_page_t * ngx_slab_alloc_pages(ngx_slab_pool_t *pool, ngx_uint_t pages) { ngx_slab_page_t *page, *p; for (page = pool->free.next; page != &pool->free; page = page->next) { if (page->slab >= pages) { if (page->slab > pages) { page[pages].slab = page->slab - pages; page[pages].next = page->next; page[pages].prev = page->prev; p = (ngx_slab_page_t *) page->prev; p->next = &page[pages]; page->next->prev = (uintptr_t) &page[pages]; } else { p = (ngx_slab_page_t *) page->prev; p->next = page->next; page->next->prev = page->prev; } page->slab = pages | NGX_SLAB_PAGE_START; page->next = NULL; page->prev = NGX_SLAB_PAGE; if (--pages == 0) { return page; } for (p = page + 1; pages; pages--) { p->slab = NGX_SLAB_PAGE_BUSY; p->next = NULL; p->prev = NGX_SLAB_PAGE; p++; } return page; } } ngx_slab_error(pool, NGX_LOG_CRIT, "ngx_slab_alloc() failed: no memory"); return NULL; } static void ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page, ngx_uint_t pages) { ngx_slab_page_t *prev; page->slab = pages--; if (pages) { ngx_memzero(&page[1], pages * sizeof(ngx_slab_page_t)); } if (page->next) { prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; } page->prev = (uintptr_t) &pool->free; page->next = pool->free.next; page->next->prev = (uintptr_t) page; pool->free.next = page; } static void ngx_slab_error(ngx_slab_pool_t *pool, ngx_uint_t level, char *text) { ngx_log_error(level, ngx_cycle->log, 0, "%s%s", text, pool->log_ctx); }