mod_include.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

                else if (leave_name) {
                    val = p;
                    len = ep - p;
                }

                if (val && len) {
                    if (out) {
                        memcpy(out, val, (out+len <= eout) ? len : (eout-out));
                        out += len;
                    }
                    else {
                        current->len = len;
                        current->string = val;
                        outlen += len;
                    }
                }

                p = newp;
            }
        }

        if ((out && out >= eout) || (length && outlen >= length)) {
            break;
        }

        /* check the remainder */
        if (*p && (span = strcspn(p, "\\$")) > 0) {
            if (!out && current->len) {
                current->next = apr_palloc(ctx->dpool, sizeof(*current->next));
                current = current->next;
                current->next = NULL;
            }

            if (out) {
                memcpy(out, p, (out+span <= eout) ? span : (eout-out));
                out += span;
            }
            else {
                current->len = span;
                current->string = p;
                outlen += span;
            }

            p += span;
        }
    } while (p < in+inlen);

    /* assemble result */
    if (out) {
        if (out > eout) {
            *eout = '\0';
        }
        else {
            *out = '\0';
        }
    }
    else {
        const char *ep;

        if (length && outlen > length) {
            outlen = length - 1;
        }

        ret = out = apr_palloc(ctx->pool, outlen + 1);
        ep = ret + outlen;

        do {
            if (result->len) {
                memcpy(out, result->string, (out+result->len <= ep)
                                            ? result->len : (ep-out));
                out += result->len;
            }
            result = result->next;
        } while (result && out < ep);

        ret[outlen] = '\0';
    }

    return ret;
}


/*
 * +-------------------------------------------------------+
 * |                                                       |
 * |              Conditional Expression Parser
 * |                                                       |
 * +-------------------------------------------------------+
 */

static APR_INLINE int re_check(include_ctx_t *ctx, const char *string,
                               const char *rexp)
{
    ap_regex_t *compiled;
    backref_t *re = ctx->intern->re;
    int rc;

    compiled = ap_pregcomp(ctx->dpool, rexp, AP_REG_EXTENDED);
    if (!compiled) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, ctx->intern->r, "unable to "
                      "compile pattern \"%s\"", rexp);
        return -1;
    }

    if (!re) {
        re = ctx->intern->re = apr_palloc(ctx->pool, sizeof(*re));
    }

    re->source = apr_pstrdup(ctx->pool, string);
    re->rexp = apr_pstrdup(ctx->pool, rexp);
    re->nsub = compiled->re_nsub;
    rc = !ap_regexec(compiled, string, AP_MAX_REG_MATCH, re->match, 0);

    ap_pregfree(ctx->dpool, compiled);
    return rc;
}

static int get_ptoken(include_ctx_t *ctx, const char **parse, token_t *token, token_t *previous)
{
    const char *p;
    apr_size_t shift;
    int unmatched;

    token->value = NULL;

    if (!*parse) {
        return 0;
    }

    /* Skip leading white space */
    while (apr_isspace(**parse)) {
        ++*parse;
    }

    if (!**parse) {
        *parse = NULL;
        return 0;
    }

    TYPE_TOKEN(token, TOKEN_STRING); /* the default type */
    p = *parse;
    unmatched = 0;

    switch (*(*parse)++) {
    case '(':
        TYPE_TOKEN(token, TOKEN_LBRACE);
        return 0;
    case ')':
        TYPE_TOKEN(token, TOKEN_RBRACE);
        return 0;
    case '=':
        if (**parse == '=') ++*parse;
        TYPE_TOKEN(token, TOKEN_EQ);
        return 0;
    case '!':
        if (**parse == '=') {
            TYPE_TOKEN(token, TOKEN_NE);
            ++*parse;
            return 0;
        }
        TYPE_TOKEN(token, TOKEN_NOT);
        return 0;
    case '\'':
        unmatched = '\'';
        break;
    case '/':
        /* if last token was ACCESS, this token is STRING */
        if (previous != NULL && TOKEN_ACCESS == previous->type) {
            break;
        }
        TYPE_TOKEN(token, TOKEN_RE);
        unmatched = '/';
        break;
    case '|':
        if (**parse == '|') {
            TYPE_TOKEN(token, TOKEN_OR);
            ++*parse;
            return 0;
        }
        break;
    case '&':
        if (**parse == '&') {
            TYPE_TOKEN(token, TOKEN_AND);
            ++*parse;
            return 0;
        }
        break;
    case '>':
        if (**parse == '=') {
            TYPE_TOKEN(token, TOKEN_GE);
            ++*parse;
            return 0;
        }
        TYPE_TOKEN(token, TOKEN_GT);
        return 0;
    case '<':
        if (**parse == '=') {
            TYPE_TOKEN(token, TOKEN_LE);
            ++*parse;
            return 0;
        }
        TYPE_TOKEN(token, TOKEN_LT);
        return 0;
    case '-':
        if (**parse == 'A' && (ctx->intern->accessenable)) {
            TYPE_TOKEN(token, TOKEN_ACCESS);
            ++*parse;
            return 0;
        }
        break;
    }

    /* It's a string or regex token
     * Now search for the next token, which finishes this string
     */
    shift = 0;
    p = *parse = token->value = unmatched ? *parse : p;

    for (; **parse; p = ++*parse) {
        if (**parse == '\\') {
            if (!*(++*parse)) {
                p = *parse;
                break;
            }

            ++shift;
        }
        else {
            if (unmatched) {
                if (**parse == unmatched) {
                    unmatched = 0;
                    ++*parse;
                    break;
                }
            } else if (apr_isspace(**parse)) {
                break;
            }
            else {
                int found = 0;

                switch (**parse) {
                case '(':
                case ')':
                case '=':
                case '!':
                case '<':
                case '>':
                    ++found;
                    break;

                case '|':
                case '&':
                    if ((*parse)[1] == **parse) {
                        ++found;
                    }
                    break;
                }

                if (found) {
                    break;
                }
            }
        }
    }

    if (unmatched) {
        token->value = apr_pstrdup(ctx->dpool, "");
    }
    else {
        apr_size_t len = p - token->value - shift;
        char *c = apr_palloc(ctx->dpool, len + 1);

        p = token->value;
        token->value = c;

        while (shift--) {
            const char *e = ap_strchr_c(p, '\\');

            memcpy(c, p, e-p);
            c   += e-p;
            *c++ = *++e;
            len -= e-p;
            p    = e+1;
        }

        if (len) {
            memcpy(c, p, len);
        }
        c[len] = '\0';
    }

    return unmatched;
}

static int parse_expr(include_ctx_t *ctx, const char *expr, int *was_error)
{
    parse_node_t *new, *root = NULL, *current = NULL;
    request_rec *r = ctx->intern->r;
    request_rec *rr = NULL;
    const char *error = "Invalid expression \"%s\" in file %s";
    const char *parse = expr;
    int was_unmatched = 0;
    unsigned regex = 0;

    *was_error = 0;

    if (!parse) {
        return 0;
    }

    /* Create Parse Tree */
    while (1) {
        /* uncomment this to see how the tree a built:
         *
         * DEBUG_DUMP_TREE(ctx, root);
         */
        CREATE_NODE(ctx, new);

        was_unmatched = get_ptoken(ctx, &parse, &new->token,
                         (current != NULL ? &current->token : NULL));
        if (!parse) {
            break;
        }

        DEBUG_DUMP_UNMATCHED(ctx, was_unmatched);
        DEBUG_DUMP_TOKEN(ctx, &new->token);

        if (!current) {
            switch (new->token.type) {
            case TOKEN_STRING:
            case TOKEN_NOT:
            case TOKEN_ACCESS:
            case TOKEN_LBRACE:
                root = current = new;
                continue;

            default:
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, error, expr,
                              r->filename);
                *was_error = 1;
                return 0;
            }
        }

        switch (new->token.type) {
        case TOKEN_STRING:
            switch (current->token.type) {
            case TOKEN_STRING:
                current->token.value =
                    apr_pstrcat(ctx->dpool, current->token.value,
                                *current->token.value ? " " : "",
                                new->token.value, NULL);
                continue;

            case TOKEN_RE:
            case TOKEN_RBRACE:
            case TOKEN_GROUP:
                break;

            default:
                new->parent = current;
                current = current->right = new;
                continue;
            }
            break;

        case TOKEN_RE:
            switch (current->token.type) {
            case TOKEN_EQ:
            case TOKEN_NE:
                new->parent = current;
                current = current->right = new;
                ++regex;
                continue;

            default:
                break;
            }
            break;

        case TOKEN_AND:
        case TOKEN_OR:
            switch (current->token.type) {
            case TOKEN_STRING:
            case TOKEN_RE:
            case TOKEN_GROUP:
                current = current->parent;

                while (current) {
                    switch (current->token.type) {
                    case TOKEN_AND:
                    case TOKEN_OR:
                    case TOKEN_LBRACE:
                        break;

                    default:
                        current = current->parent;
                        continue;
                    }
                    break;
                }

                if (!current) {
                    new->left = root;
                    root->parent = new;
                    current = root = new;
                    continue;
                }

                new->left = current->right;
                new->left->parent = new;
                new->parent = current;
                current = current->right = new;
                continue;