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view src/core/ngx_output_chain.c @ 8122:106328a70f4e

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Added warning about redefinition of listen socket protocol options. The "listen" directive in the http module can be used multiple times in different server blocks. Originally, it was supposed to be specified once with various socket options, and without any parameters in virtual server blocks. For example: server { listen 80 backlog=1024; server_name foo; ... } server { listen 80; server_name bar; ... } server { listen 80; server_name bazz; ... } The address part of the syntax ("address[:port]" / "port" / "unix:path") uniquely identifies the listening socket, and therefore is enough for name-based virtual servers (to let nginx know that the virtual server accepts requests on the listening socket in question). To ensure that listening options do not conflict between virtual servers, they were allowed only once. For example, the following configuration will be rejected ("duplicate listen options for 0.0.0.0:80 in ..."): server { listen 80 backlog=1024; server_name foo; ... } server { listen 80 backlog=512; server_name bar; ... } At some point it was, however, noticed, that it is sometimes convenient to repeat some options for clarity. In nginx 0.8.51 the "ssl" parameter was allowed to be specified multiple times, e.g.: server { listen 443 ssl backlog=1024; server_name foo; ... } server { listen 443 ssl; server_name bar; ... } server { listen 443 ssl; server_name bazz; ... } This approach makes configuration more readable, since SSL sockets are immediately visible in the configuration. If this is not needed, just the address can still be used. Later, additional protocol-specific options similar to "ssl" were introduced, notably "http2" and "proxy_protocol". With these options, one can write: server { listen 443 ssl backlog=1024; server_name foo; ... } server { listen 443 http2; server_name bar; ... } server { listen 443 proxy_protocol; server_name bazz; ... } The resulting socket will use ssl, http2, and proxy_protocol, but this is not really obvious from the configuration. To emphasize such misleading configurations are discouraged, nginx now warns as long as the "listen" directive is used with options different from the options previously used if this is potentially confusing. In particular, the following configurations are allowed: server { listen 8401 ssl backlog=1024; server_name foo; } server { listen 8401 ssl; server_name bar; } server { listen 8401 ssl; server_name bazz; } server { listen 8402 ssl http2 backlog=1024; server_name foo; } server { listen 8402 ssl; server_name bar; } server { listen 8402 ssl; server_name bazz; } server { listen 8403 ssl; server_name bar; } server { listen 8403 ssl; server_name bazz; } server { listen 8403 ssl http2; server_name foo; } server { listen 8404 ssl http2 backlog=1024; server_name foo; } server { listen 8404 http2; server_name bar; } server { listen 8404 http2; server_name bazz; } server { listen 8405 ssl http2 backlog=1024; server_name foo; } server { listen 8405 ssl http2; server_name bar; } server { listen 8405 ssl http2; server_name bazz; } server { listen 8406 ssl; server_name foo; } server { listen 8406; server_name bar; } server { listen 8406; server_name bazz; } And the following configurations will generate warnings: server { listen 8501 ssl http2 backlog=1024; server_name foo; } server { listen 8501 http2; server_name bar; } server { listen 8501 ssl; server_name bazz; } server { listen 8502 backlog=1024; server_name foo; } server { listen 8502 ssl; server_name bar; } server { listen 8503 ssl; server_name foo; } server { listen 8503 http2; server_name bar; } server { listen 8504 ssl; server_name foo; } server { listen 8504 http2; server_name bar; } server { listen 8504 proxy_protocol; server_name bazz; } server { listen 8505 ssl http2 proxy_protocol; server_name foo; } server { listen 8505 ssl http2; server_name bar; } server { listen 8505 ssl; server_name bazz; } server { listen 8506 ssl http2; server_name foo; } server { listen 8506 ssl; server_name bar; } server { listen 8506; server_name bazz; } server { listen 8507 ssl; server_name bar; } server { listen 8507; server_name bazz; } server { listen 8507 ssl http2; server_name foo; } server { listen 8508 ssl; server_name bar; } server { listen 8508; server_name bazz; } server { listen 8508 ssl backlog=1024; server_name foo; } server { listen 8509; server_name bazz; } server { listen 8509 ssl; server_name bar; } server { listen 8509 ssl backlog=1024; server_name foo; } The basic idea is that at most two sets of protocol options are allowed: the main one (with socket options, if any), and a shorter one, with options being a subset of the main options, repeated for clarity. As long as the shorter set of protocol options is used, all listen directives except the main one should use it.
author Maxim Dounin <mdounin@mdounin.ru>
date Sat, 28 Jan 2023 01:29:45 +0300
parents b002ad258f1d
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>


#if 0
#define NGX_SENDFILE_LIMIT  4096
#endif

/*
 * When DIRECTIO is enabled FreeBSD, Solaris, and MacOSX read directly
 * to an application memory from a device if parameters are aligned
 * to device sector boundary (512 bytes).  They fallback to usual read
 * operation if the parameters are not aligned.
 * Linux allows DIRECTIO only if the parameters are aligned to a filesystem
 * sector boundary, otherwise it returns EINVAL.  The sector size is
 * usually 512 bytes, however, on XFS it may be 4096 bytes.
 */

#define NGX_NONE            1


static ngx_inline ngx_int_t
    ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf);
static ngx_int_t ngx_output_chain_add_copy(ngx_pool_t *pool,
    ngx_chain_t **chain, ngx_chain_t *in);
static ngx_int_t ngx_output_chain_align_file_buf(ngx_output_chain_ctx_t *ctx,
    off_t bsize);
static ngx_int_t ngx_output_chain_get_buf(ngx_output_chain_ctx_t *ctx,
    off_t bsize);
static ngx_int_t ngx_output_chain_copy_buf(ngx_output_chain_ctx_t *ctx);


ngx_int_t
ngx_output_chain(ngx_output_chain_ctx_t *ctx, ngx_chain_t *in)
{
    off_t         bsize;
    ngx_int_t     rc, last;
    ngx_chain_t  *cl, *out, **last_out;

    if (ctx->in == NULL && ctx->busy == NULL
#if (NGX_HAVE_FILE_AIO || NGX_THREADS)
        && !ctx->aio
#endif
       )
    {
        /*
         * the short path for the case when the ctx->in and ctx->busy chains
         * are empty, the incoming chain is empty too or has the single buf
         * that does not require the copy
         */

        if (in == NULL) {
            return ctx->output_filter(ctx->filter_ctx, in);
        }

        if (in->next == NULL
#if (NGX_SENDFILE_LIMIT)
            && !(in->buf->in_file && in->buf->file_last > NGX_SENDFILE_LIMIT)
#endif
            && ngx_output_chain_as_is(ctx, in->buf))
        {
            return ctx->output_filter(ctx->filter_ctx, in);
        }
    }

    /* add the incoming buf to the chain ctx->in */

    if (in) {
        if (ngx_output_chain_add_copy(ctx->pool, &ctx->in, in) == NGX_ERROR) {
            return NGX_ERROR;
        }
    }

    out = NULL;
    last_out = &out;
    last = NGX_NONE;

    for ( ;; ) {

#if (NGX_HAVE_FILE_AIO || NGX_THREADS)
        if (ctx->aio) {
            return NGX_AGAIN;
        }
#endif

        while (ctx->in) {

            /*
             * cycle while there are the ctx->in bufs
             * and there are the free output bufs to copy in
             */

            bsize = ngx_buf_size(ctx->in->buf);

            if (bsize == 0 && !ngx_buf_special(ctx->in->buf)) {

                ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                              "zero size buf in output "
                              "t:%d r:%d f:%d %p %p-%p %p %O-%O",
                              ctx->in->buf->temporary,
                              ctx->in->buf->recycled,
                              ctx->in->buf->in_file,
                              ctx->in->buf->start,
                              ctx->in->buf->pos,
                              ctx->in->buf->last,
                              ctx->in->buf->file,
                              ctx->in->buf->file_pos,
                              ctx->in->buf->file_last);

                ngx_debug_point();

                ctx->in = ctx->in->next;

                continue;
            }

            if (bsize < 0) {

                ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                              "negative size buf in output "
                              "t:%d r:%d f:%d %p %p-%p %p %O-%O",
                              ctx->in->buf->temporary,
                              ctx->in->buf->recycled,
                              ctx->in->buf->in_file,
                              ctx->in->buf->start,
                              ctx->in->buf->pos,
                              ctx->in->buf->last,
                              ctx->in->buf->file,
                              ctx->in->buf->file_pos,
                              ctx->in->buf->file_last);

                ngx_debug_point();

                return NGX_ERROR;
            }

            if (ngx_output_chain_as_is(ctx, ctx->in->buf)) {

                /* move the chain link to the output chain */

                cl = ctx->in;
                ctx->in = cl->next;

                *last_out = cl;
                last_out = &cl->next;
                cl->next = NULL;

                continue;
            }

            if (ctx->buf == NULL) {

                rc = ngx_output_chain_align_file_buf(ctx, bsize);

                if (rc == NGX_ERROR) {
                    return NGX_ERROR;
                }

                if (rc != NGX_OK) {

                    if (ctx->free) {

                        /* get the free buf */

                        cl = ctx->free;
                        ctx->buf = cl->buf;
                        ctx->free = cl->next;

                        ngx_free_chain(ctx->pool, cl);

                    } else if (out || ctx->allocated == ctx->bufs.num) {

                        break;

                    } else if (ngx_output_chain_get_buf(ctx, bsize) != NGX_OK) {
                        return NGX_ERROR;
                    }
                }
            }

            rc = ngx_output_chain_copy_buf(ctx);

            if (rc == NGX_ERROR) {
                return rc;
            }

            if (rc == NGX_AGAIN) {
                if (out) {
                    break;
                }

                return rc;
            }

            /* delete the completed buf from the ctx->in chain */

            if (ngx_buf_size(ctx->in->buf) == 0) {
                ctx->in = ctx->in->next;
            }

            cl = ngx_alloc_chain_link(ctx->pool);
            if (cl == NULL) {
                return NGX_ERROR;
            }

            cl->buf = ctx->buf;
            cl->next = NULL;
            *last_out = cl;
            last_out = &cl->next;
            ctx->buf = NULL;
        }

        if (out == NULL && last != NGX_NONE) {

            if (ctx->in) {
                return NGX_AGAIN;
            }

            return last;
        }

        last = ctx->output_filter(ctx->filter_ctx, out);

        if (last == NGX_ERROR || last == NGX_DONE) {
            return last;
        }

        ngx_chain_update_chains(ctx->pool, &ctx->free, &ctx->busy, &out,
                                ctx->tag);
        last_out = &out;
    }
}


static ngx_inline ngx_int_t
ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf)
{
    ngx_uint_t  sendfile;

    if (ngx_buf_special(buf)) {
        return 1;
    }

#if (NGX_THREADS)
    if (buf->in_file) {
        buf->file->thread_handler = ctx->thread_handler;
        buf->file->thread_ctx = ctx->filter_ctx;
    }
#endif

    sendfile = ctx->sendfile;

#if (NGX_SENDFILE_LIMIT)

    if (buf->in_file && buf->file_pos >= NGX_SENDFILE_LIMIT) {
        sendfile = 0;
    }

#endif

#if !(NGX_HAVE_SENDFILE_NODISKIO)

    /*
     * With DIRECTIO, disable sendfile() unless sendfile(SF_NOCACHE)
     * is available.
     */

    if (buf->in_file && buf->file->directio) {
        sendfile = 0;
    }

#endif

    if (!sendfile) {

        if (!ngx_buf_in_memory(buf)) {
            return 0;
        }

        buf->in_file = 0;
    }

    if (ctx->need_in_memory && !ngx_buf_in_memory(buf)) {
        return 0;
    }

    if (ctx->need_in_temp && (buf->memory || buf->mmap)) {
        return 0;
    }

    return 1;
}


static ngx_int_t
ngx_output_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
    ngx_chain_t *in)
{
    ngx_chain_t  *cl, **ll;
#if (NGX_SENDFILE_LIMIT)
    ngx_buf_t    *b, *buf;
#endif

    ll = chain;

    for (cl = *chain; cl; cl = cl->next) {
        ll = &cl->next;
    }

    while (in) {

        cl = ngx_alloc_chain_link(pool);
        if (cl == NULL) {
            return NGX_ERROR;
        }

#if (NGX_SENDFILE_LIMIT)

        buf = in->buf;

        if (buf->in_file
            && buf->file_pos < NGX_SENDFILE_LIMIT
            && buf->file_last > NGX_SENDFILE_LIMIT)
        {
            /* split a file buf on two bufs by the sendfile limit */

            b = ngx_calloc_buf(pool);
            if (b == NULL) {
                return NGX_ERROR;
            }

            ngx_memcpy(b, buf, sizeof(ngx_buf_t));

            if (ngx_buf_in_memory(buf)) {
                buf->pos += (ssize_t) (NGX_SENDFILE_LIMIT - buf->file_pos);
                b->last = buf->pos;
            }

            buf->file_pos = NGX_SENDFILE_LIMIT;
            b->file_last = NGX_SENDFILE_LIMIT;

            cl->buf = b;

        } else {
            cl->buf = buf;
            in = in->next;
        }

#else
        cl->buf = in->buf;
        in = in->next;

#endif

        cl->next = NULL;
        *ll = cl;
        ll = &cl->next;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_output_chain_align_file_buf(ngx_output_chain_ctx_t *ctx, off_t bsize)
{
    size_t      size;
    ngx_buf_t  *in;

    in = ctx->in->buf;

    if (in->file == NULL || !in->file->directio) {
        return NGX_DECLINED;
    }

    ctx->directio = 1;

    size = (size_t) (in->file_pos - (in->file_pos & ~(ctx->alignment - 1)));

    if (size == 0) {

        if (bsize >= (off_t) ctx->bufs.size) {
            return NGX_DECLINED;
        }

        size = (size_t) bsize;

    } else {
        size = (size_t) ctx->alignment - size;

        if ((off_t) size > bsize) {
            size = (size_t) bsize;
        }
    }

    ctx->buf = ngx_create_temp_buf(ctx->pool, size);
    if (ctx->buf == NULL) {
        return NGX_ERROR;
    }

    /*
     * we do not set ctx->buf->tag, because we do not want
     * to reuse the buf via ctx->free list
     */

#if (NGX_HAVE_ALIGNED_DIRECTIO)
    ctx->unaligned = 1;
#endif

    return NGX_OK;
}


static ngx_int_t
ngx_output_chain_get_buf(ngx_output_chain_ctx_t *ctx, off_t bsize)
{
    size_t       size;
    ngx_buf_t   *b, *in;
    ngx_uint_t   recycled;

    in = ctx->in->buf;
    size = ctx->bufs.size;
    recycled = 1;

    if (in->last_in_chain) {

        if (bsize < (off_t) size) {

            /*
             * allocate a small temp buf for a small last buf
             * or its small last part
             */

            size = (size_t) bsize;
            recycled = 0;

        } else if (!ctx->directio
                   && ctx->bufs.num == 1
                   && (bsize < (off_t) (size + size / 4)))
        {
            /*
             * allocate a temp buf that equals to a last buf,
             * if there is no directio, the last buf size is lesser
             * than 1.25 of bufs.size and the temp buf is single
             */

            size = (size_t) bsize;
            recycled = 0;
        }
    }

    b = ngx_calloc_buf(ctx->pool);
    if (b == NULL) {
        return NGX_ERROR;
    }

    if (ctx->directio) {

        /*
         * allocate block aligned to a disk sector size to enable
         * userland buffer direct usage conjunctly with directio
         */

        b->start = ngx_pmemalign(ctx->pool, size, (size_t) ctx->alignment);
        if (b->start == NULL) {
            return NGX_ERROR;
        }

    } else {
        b->start = ngx_palloc(ctx->pool, size);
        if (b->start == NULL) {
            return NGX_ERROR;
        }
    }

    b->pos = b->start;
    b->last = b->start;
    b->end = b->last + size;
    b->temporary = 1;
    b->tag = ctx->tag;
    b->recycled = recycled;

    ctx->buf = b;
    ctx->allocated++;

    return NGX_OK;
}


static ngx_int_t
ngx_output_chain_copy_buf(ngx_output_chain_ctx_t *ctx)
{
    off_t        size;
    ssize_t      n;
    ngx_buf_t   *src, *dst;
    ngx_uint_t   sendfile;

    src = ctx->in->buf;
    dst = ctx->buf;

    size = ngx_buf_size(src);
    size = ngx_min(size, dst->end - dst->pos);

    sendfile = ctx->sendfile && !ctx->directio;

#if (NGX_SENDFILE_LIMIT)

    if (src->in_file && src->file_pos >= NGX_SENDFILE_LIMIT) {
        sendfile = 0;
    }

#endif

    if (ngx_buf_in_memory(src)) {
        ngx_memcpy(dst->pos, src->pos, (size_t) size);
        src->pos += (size_t) size;
        dst->last += (size_t) size;

        if (src->in_file) {

            if (sendfile) {
                dst->in_file = 1;
                dst->file = src->file;
                dst->file_pos = src->file_pos;
                dst->file_last = src->file_pos + size;

            } else {
                dst->in_file = 0;
            }

            src->file_pos += size;

        } else {
            dst->in_file = 0;
        }

        if (src->pos == src->last) {
            dst->flush = src->flush;
            dst->last_buf = src->last_buf;
            dst->last_in_chain = src->last_in_chain;
        }

    } else {

#if (NGX_HAVE_ALIGNED_DIRECTIO)

        if (ctx->unaligned) {
            if (ngx_directio_off(src->file->fd) == NGX_FILE_ERROR) {
                ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, ngx_errno,
                              ngx_directio_off_n " \"%s\" failed",
                              src->file->name.data);
            }
        }

#endif

#if (NGX_HAVE_FILE_AIO)
        if (ctx->aio_handler) {
            n = ngx_file_aio_read(src->file, dst->pos, (size_t) size,
                                  src->file_pos, ctx->pool);
            if (n == NGX_AGAIN) {
                ctx->aio_handler(ctx, src->file);
                return NGX_AGAIN;
            }

        } else
#endif
#if (NGX_THREADS)
        if (ctx->thread_handler) {
            src->file->thread_task = ctx->thread_task;
            src->file->thread_handler = ctx->thread_handler;
            src->file->thread_ctx = ctx->filter_ctx;

            n = ngx_thread_read(src->file, dst->pos, (size_t) size,
                                src->file_pos, ctx->pool);
            if (n == NGX_AGAIN) {
                ctx->thread_task = src->file->thread_task;
                return NGX_AGAIN;
            }

        } else
#endif
        {
            n = ngx_read_file(src->file, dst->pos, (size_t) size,
                              src->file_pos);
        }

#if (NGX_HAVE_ALIGNED_DIRECTIO)

        if (ctx->unaligned) {
            ngx_err_t  err;

            err = ngx_errno;

            if (ngx_directio_on(src->file->fd) == NGX_FILE_ERROR) {
                ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, ngx_errno,
                              ngx_directio_on_n " \"%s\" failed",
                              src->file->name.data);
            }

            ngx_set_errno(err);

            ctx->unaligned = 0;
        }

#endif

        if (n == NGX_ERROR) {
            return (ngx_int_t) n;
        }

        if (n != size) {
            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                          ngx_read_file_n " read only %z of %O from \"%s\"",
                          n, size, src->file->name.data);
            return NGX_ERROR;
        }

        dst->last += n;

        if (sendfile) {
            dst->in_file = 1;
            dst->file = src->file;
            dst->file_pos = src->file_pos;
            dst->file_last = src->file_pos + n;

        } else {
            dst->in_file = 0;
        }

        src->file_pos += n;

        if (src->file_pos == src->file_last) {
            dst->flush = src->flush;
            dst->last_buf = src->last_buf;
            dst->last_in_chain = src->last_in_chain;
        }
    }

    return NGX_OK;
}


ngx_int_t
ngx_chain_writer(void *data, ngx_chain_t *in)
{
    ngx_chain_writer_ctx_t *ctx = data;

    off_t              size;
    ngx_chain_t       *cl, *ln, *chain;
    ngx_connection_t  *c;

    c = ctx->connection;

    for (size = 0; in; in = in->next) {

        if (ngx_buf_size(in->buf) == 0 && !ngx_buf_special(in->buf)) {

            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                          "zero size buf in chain writer "
                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
                          in->buf->temporary,
                          in->buf->recycled,
                          in->buf->in_file,
                          in->buf->start,
                          in->buf->pos,
                          in->buf->last,
                          in->buf->file,
                          in->buf->file_pos,
                          in->buf->file_last);

            ngx_debug_point();

            continue;
        }

        if (ngx_buf_size(in->buf) < 0) {

            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                          "negative size buf in chain writer "
                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
                          in->buf->temporary,
                          in->buf->recycled,
                          in->buf->in_file,
                          in->buf->start,
                          in->buf->pos,
                          in->buf->last,
                          in->buf->file,
                          in->buf->file_pos,
                          in->buf->file_last);

            ngx_debug_point();

            return NGX_ERROR;
        }

        size += ngx_buf_size(in->buf);

        ngx_log_debug2(NGX_LOG_DEBUG_CORE, c->log, 0,
                       "chain writer buf fl:%d s:%uO",
                       in->buf->flush, ngx_buf_size(in->buf));

        cl = ngx_alloc_chain_link(ctx->pool);
        if (cl == NULL) {
            return NGX_ERROR;
        }

        cl->buf = in->buf;
        cl->next = NULL;
        *ctx->last = cl;
        ctx->last = &cl->next;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                   "chain writer in: %p", ctx->out);

    for (cl = ctx->out; cl; cl = cl->next) {

        if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {

            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                          "zero size buf in chain writer "
                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
                          cl->buf->temporary,
                          cl->buf->recycled,
                          cl->buf->in_file,
                          cl->buf->start,
                          cl->buf->pos,
                          cl->buf->last,
                          cl->buf->file,
                          cl->buf->file_pos,
                          cl->buf->file_last);

            ngx_debug_point();

            continue;
        }

        if (ngx_buf_size(cl->buf) < 0) {

            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
                          "negative size buf in chain writer "
                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
                          cl->buf->temporary,
                          cl->buf->recycled,
                          cl->buf->in_file,
                          cl->buf->start,
                          cl->buf->pos,
                          cl->buf->last,
                          cl->buf->file,
                          cl->buf->file_pos,
                          cl->buf->file_last);

            ngx_debug_point();

            return NGX_ERROR;
        }

        size += ngx_buf_size(cl->buf);
    }

    if (size == 0 && !c->buffered) {
        return NGX_OK;
    }

    chain = c->send_chain(c, ctx->out, ctx->limit);

    ngx_log_debug1(NGX_LOG_DEBUG_CORE, c->log, 0,
                   "chain writer out: %p", chain);

    if (chain == NGX_CHAIN_ERROR) {
        return NGX_ERROR;
    }

    if (chain && c->write->ready) {
        ngx_post_event(c->write, &ngx_posted_next_events);
    }

    for (cl = ctx->out; cl && cl != chain; /* void */) {
        ln = cl;
        cl = cl->next;
        ngx_free_chain(ctx->pool, ln);
    }

    ctx->out = chain;

    if (ctx->out == NULL) {
        ctx->last = &ctx->out;

        if (!c->buffered) {
            return NGX_OK;
        }
    }

    return NGX_AGAIN;
}