ngx_http_ssi_filter_module.c

Nginx是一个高性能的HTTP和反向代理服务器

                value = ngx_palloc(r->pool, ctx->param->value.len + 1);
                if (value == NULL) {
                    return NGX_ERROR;
                }

                ngx_memcpy(value, ctx->param->value.data,
                           ctx->param->value.len);

                ctx->value_buf = ctx->param->value.data;
                ctx->param->value.data = value;

            } else {
                ctx->value_buf = NULL;
            }

            switch (ch) {
            case ' ':
            case CR:
            case LF:
            case '\t':
                state = ssi_preparam_state;
                break;

            case '-':
                state = ssi_comment_end0_state;
                break;

            default:
                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                              "unexpected \"%c\" symbol after \"%V\" value "
                              "of \"%V\" parameter in \"%V\" SSI command",
                              ch, &ctx->param->value, &ctx->param->key,
                              &ctx->command);
                state = ssi_error_state;
                break;
            }

            break;

        case ssi_comment_end0_state:
            switch (ch) {
            case '-':
                state = ssi_comment_end1_state;
                break;

            default:
                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                              "unexpected \"%c\" symbol in \"%V\" SSI command",
                              ch, &ctx->command);
                state = ssi_error_state;
                break;
            }

            break;

        case ssi_comment_end1_state:
            switch (ch) {
            case '>':
                ctx->state = ssi_start_state;
                ctx->pos = p + 1;
                ctx->looked = looked;
                ctx->copy_end = copy_end;

                if (ctx->copy_start == NULL && copy_end) {
                    ctx->copy_start = ctx->buf->pos;
                }

                return NGX_OK;

            default:
                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                              "unexpected \"%c\" symbol in \"%V\" SSI command",
                              ch, &ctx->command);
                state = ssi_error_state;
                break;
            }

            break;

        case ssi_error_state:
            switch (ch) {
            case '-':
                state = ssi_error_end0_state;
                break;

            default:
                break;
            }

            break;

        case ssi_error_end0_state:
            switch (ch) {
            case '-':
                state = ssi_error_end1_state;
                break;

            default:
                state = ssi_error_state;
                break;
            }

            break;

        case ssi_error_end1_state:
            switch (ch) {
            case '>':
                ctx->state = ssi_start_state;
                ctx->pos = p + 1;
                ctx->looked = looked;
                ctx->copy_end = copy_end;

                if (ctx->copy_start == NULL && copy_end) {
                    ctx->copy_start = ctx->buf->pos;
                }

                return NGX_HTTP_SSI_ERROR;

            default:
                state = ssi_error_state;
                break;
            }

            break;
        }
    }

    ctx->state = state;
    ctx->pos = p;
    ctx->looked = looked;

    ctx->copy_end = (state == ssi_start_state) ? p : copy_end;

    if (ctx->copy_start == NULL && ctx->copy_end) {
        ctx->copy_start = ctx->buf->pos;
    }

    return NGX_AGAIN;
}


static ngx_str_t *
ngx_http_ssi_get_variable(ngx_http_request_t *r, ngx_str_t *name,
    ngx_uint_t key)
{
    ngx_uint_t           i;
    ngx_list_part_t     *part;
    ngx_http_ssi_var_t  *var;
    ngx_http_ssi_ctx_t  *ctx;

    ctx = ngx_http_get_module_ctx(r->main, ngx_http_ssi_filter_module);

    if (ctx->variables == NULL) {
        return NULL;
    }

    part = &ctx->variables->part;
    var = part->elts;

    for (i = 0; /* void */ ; i++) {

        if (i >= part->nelts) {
            if (part->next == NULL) {
                break;
            }

            part = part->next;
            var = part->elts;
            i = 0;
        }

        if (name->len != var[i].name.len) {
            continue;
        }

        if (key != var[i].key) {
            continue;
        }

        if (ngx_strncmp(name->data, var[i].name.data, name->len) == 0) {
            return &var[i].value;
        }
    }

    return NULL;
}


static ngx_int_t
ngx_http_ssi_evaluate_string(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx,
    ngx_str_t *text, ngx_uint_t flags)
{
    u_char                      ch, *p, **value, *data, *part_data;
    size_t                     *size, len, prefix, part_len;
    ngx_str_t                   var, *val;
    ngx_int_t                   key;
    ngx_uint_t                  i, j, n, bracket, quoted;
    ngx_array_t                 lengths, values;
    ngx_http_variable_value_t  *vv;

    n = ngx_http_script_variables_count(text);

    if (n == 0) {

        data = text->data;
        p = data;

        if ((flags & NGX_HTTP_SSI_ADD_PREFIX) && text->data[0] != '/') {

            for (prefix = r->uri.len; prefix; prefix--) {
                if (r->uri.data[prefix - 1] == '/') {
                    break;
                }
            }

            if (prefix) {
                len = prefix + text->len;

                data = ngx_palloc(r->pool, len);
                if (data == NULL) {
                    return NGX_ERROR;
                }

                p = ngx_copy(data, r->uri.data, prefix);
            }
        }

        quoted = 0;

        for (i = 0 ; i < text->len; i++) {
            ch = text->data[i];

            if (!quoted) {

                if (ch == '\\') {
                    quoted = 1;
                    continue;
                }

            } else {
                quoted = 0;

                if (ch != '\\' && ch != '\'' && ch != '"' && ch != '$') {
                    *p++ = '\\';
                }
            }

            *p++ = ch;
        }

        text->len = p - data;
        text->data = data;

        return NGX_OK;
    }

    if (ngx_array_init(&lengths, r->pool, 8, sizeof(size_t *)) != NGX_OK) {
        return NGX_ERROR;
    }

    if (ngx_array_init(&values, r->pool, 8, sizeof(u_char *)) != NGX_OK) {
        return NGX_ERROR;
    }

    len = 0;
    i = 0;

    while (i < text->len) {

        if (text->data[i] == '$') {

            var.len = 0;

            if (++i == text->len) {
                goto invalid_variable;
            }

            if (text->data[i] == '{') {
                bracket = 1;

                if (++i == text->len) {
                    goto invalid_variable;
                }

                var.data = &text->data[i];

            } else {
                bracket = 0;
                var.data = &text->data[i];
            }

            for ( /* void */ ; i < text->len; i++, var.len++) {
                ch = text->data[i];

                if (ch == '}' && bracket) {
                    i++;
                    bracket = 0;
                    break;
                }

                if ((ch >= 'A' && ch <= 'Z')
                    || (ch >= 'a' && ch <= 'z')
                    || (ch >= '0' && ch <= '9')
                    || ch == '_')
                {
                    continue;
                }

                break;
            }

            if (bracket) {
                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                              "the closing bracket in \"%V\" "
                              "variable is missing", &var);
                return NGX_HTTP_SSI_ERROR;
            }

            if (var.len == 0) {
                goto invalid_variable;
            }

            key = 0;

            for (j = 0; j < var.len; j++) {
                var.data[j] = ngx_tolower(var.data[j]);
                key = ngx_hash(key, var.data[j]);
            }

            val = ngx_http_ssi_get_variable(r, &var, key);

            if (val == NULL) {
                vv = ngx_http_get_variable(r, &var, key,
                                           flags & NGX_HTTP_SSI_EXPR_TEST);
                if (vv == NULL) {
                    return NGX_ERROR;
                }

                if (vv->not_found) {
                    continue;
                }

                part_data = vv->data;
                part_len = vv->len;

            } else {
                part_data = val->data;
                part_len = val->len;
            }

        } else {
            part_data = &text->data[i];
            quoted = 0;

            for (p = part_data; i < text->len; i++) {
                ch = text->data[i];

                if (!quoted) {

                    if (ch == '\\') {
                        quoted = 1;
                        continue;
                    }

                    if (ch == '$') {
                        break;
                    }

                } else {
                    quoted = 0;

                    if (ch != '\\' && ch != '\'' && ch != '"' && ch != '$') {
                        *p++ = '\\';
                    }
                }

                *p++ = ch;
            }

            part_len = p - part_data;
        }

        len += part_len;

        size = ngx_array_push(&lengths);
        if (size == NULL) {
            return NGX_ERROR;
        }

        *size = part_len;

        value = ngx_array_push(&values);
        if (value == NULL) {
            return NGX_ERROR;
        }

        *value = part_data;
    }

    prefix = 0;

    size = lengths.elts;
    value = values.elts;

    if (flags & NGX_HTTP_SSI_ADD_PREFIX) {
        for (i = 0; i < values.nelts; i++) {
            if (size[i] != 0) {
                if (*value[i] != '/') {
                    for (prefix = r->uri.len; prefix; prefix--) {
                        if (r->uri.data[prefix - 1] == '/') {
                            len += prefix;
                            break;
                        }
                    }
                }

                break;
            }
        }
    }

    p = ngx_palloc(r->pool, len + ((flags & NGX_HTTP_SSI_ADD_ZERO) ? 1 : 0));
    if (p == NULL) {
        return NGX_ERROR;
    }

    text->len = len;
    text->data = p;

    p = ngx_copy(p, r->uri.data, prefix);

    for (i = 0; i < values.nelts; i++) {
        p = ngx_copy(p, value[i], size[i]);
    }

    return NGX_OK;

invalid_variable:

    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                  "invalid variable name in \"%V\"", text);

    return NGX_HTTP_SSI_ERROR;
}


static ngx_int_t
ngx_http_ssi_include(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx,
    ngx_str_t **params)
{
    u_char                      *dst, *src;
    size_t                       len;
    ngx_int_t                    rc, key;
    ngx_str_t                   *uri, *file, *wait, *set, *stub, args;
    ngx_buf_t                   *b;
    ngx_uint_t                   flags, i;
    ngx_chain_t                 *cl, *tl, **ll, *out;
    ngx_http_request_t          *sr;
    ngx_http_ssi_var_t          *var;
    ngx_http_ssi_ctx_t          *mctx;
    ngx_http_ssi_block_t        *bl;
    ngx_http_post_subrequest_t  *psr;

    uri = params[NGX_HTTP_SSI_INCLUDE_VIRTUAL];
    file = params[NGX_HTTP_SSI_INCLUDE_FILE];
    wait = params[NGX_HTTP_SSI_INCLUDE_WAIT];
    set = params[NGX_HTTP_SSI_INCLUDE_SET];
    stub = params[NGX_HTTP_SSI_INCLUDE_STUB];

    if (uri && file) {