Mercurial > hg > nginx-quic
view src/core/ngx_shmtx.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 | 0daede16d68b |
children | 3f6040cd731e 4919fb357a5d |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_HAVE_ATOMIC_OPS) ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name) { mtx->lock = addr; if (mtx->spin == (ngx_uint_t) -1) { return NGX_OK; } mtx->spin = 2048; #if (NGX_HAVE_POSIX_SEM) if (sem_init(&mtx->sem, 1, 0) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, "sem_init() failed"); } else { mtx->semaphore = 1; } #endif return NGX_OK; } void ngx_shmtx_destory(ngx_shmtx_t *mtx) { #if (NGX_HAVE_POSIX_SEM) if (mtx->semaphore) { if (sem_destroy(&mtx->sem) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, "sem_destroy() failed"); } } #endif } ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx) { ngx_atomic_uint_t val; val = *mtx->lock; return ((val & 0x80000000) == 0 && ngx_atomic_cmp_set(mtx->lock, val, val | 0x80000000)); } void ngx_shmtx_lock(ngx_shmtx_t *mtx) { ngx_uint_t i, n; ngx_atomic_uint_t val; ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx lock"); for ( ;; ) { val = *mtx->lock; if ((val & 0x80000000) == 0 && ngx_atomic_cmp_set(mtx->lock, val, val | 0x80000000)) { return; } if (ngx_ncpu > 1) { for (n = 1; n < mtx->spin; n <<= 1) { for (i = 0; i < n; i++) { ngx_cpu_pause(); } val = *mtx->lock; if ((val & 0x80000000) == 0 && ngx_atomic_cmp_set(mtx->lock, val, val | 0x80000000)) { return; } } } #if (NGX_HAVE_POSIX_SEM) if (mtx->semaphore) { val = *mtx->lock; if ((val & 0x80000000) && ngx_atomic_cmp_set(mtx->lock, val, val + 1)) { ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx wait %XA", val); while (sem_wait(&mtx->sem) == -1) { ngx_err_t err; err = ngx_errno; if (err != NGX_EINTR) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, err, "sem_wait() failed while waiting on shmtx"); break; } } ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx awoke"); } continue; } #endif ngx_sched_yield(); } } void ngx_shmtx_unlock(ngx_shmtx_t *mtx) { ngx_atomic_uint_t val, old, wait; if (mtx->spin != (ngx_uint_t) -1) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx unlock"); } for ( ;; ) { old = *mtx->lock; wait = old & 0x7fffffff; val = wait ? wait - 1 : 0; if (ngx_atomic_cmp_set(mtx->lock, old, val)) { break; } } #if (NGX_HAVE_POSIX_SEM) if (wait == 0 || !mtx->semaphore) { return; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx wake %XA", old); if (sem_post(&mtx->sem) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, "sem_post() failed while wake shmtx"); } #endif } #else ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name) { if (mtx->name) { if (ngx_strcmp(name, mtx->name) == 0) { mtx->name = name; return NGX_OK; } ngx_shmtx_destory(mtx); } mtx->fd = ngx_open_file(name, NGX_FILE_RDWR, NGX_FILE_CREATE_OR_OPEN, NGX_FILE_DEFAULT_ACCESS); if (mtx->fd == NGX_INVALID_FILE) { ngx_log_error(NGX_LOG_EMERG, ngx_cycle->log, ngx_errno, ngx_open_file_n " \"%s\" failed", name); return NGX_ERROR; } if (ngx_delete_file(name) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, ngx_delete_file_n " \"%s\" failed", name); } mtx->name = name; return NGX_OK; } void ngx_shmtx_destory(ngx_shmtx_t *mtx) { if (ngx_close_file(mtx->fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, ngx_close_file_n " \"%s\" failed", mtx->name); } } ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx) { ngx_err_t err; err = ngx_trylock_fd(mtx->fd); if (err == 0) { return 1; } if (err == NGX_EAGAIN) { return 0; } #if __osf__ /* Tru64 UNIX */ if (err == NGX_EACCESS) { return 0; } #endif ngx_log_abort(err, ngx_trylock_fd_n " %s failed", mtx->name); return 0; } void ngx_shmtx_lock(ngx_shmtx_t *mtx) { ngx_err_t err; err = ngx_lock_fd(mtx->fd); if (err == 0) { return; } ngx_log_abort(err, ngx_lock_fd_n " %s failed", mtx->name); } void ngx_shmtx_unlock(ngx_shmtx_t *mtx) { ngx_err_t err; err = ngx_unlock_fd(mtx->fd); if (err == 0) { return; } ngx_log_abort(err, ngx_unlock_fd_n " %s failed", mtx->name); } #endif