mod_include.c

apache简化版

                            "to tag exec in file %s",
                            tag, r->filename);
                ap_rputs(error, r);
            }
            /* just in case some stooge changed directories */
#ifndef WIN32
            ap_chdir_file(r->filename);
#endif
        }
        else if (!strcmp(tag, "cgi")) {
            parse_string(r, tag_val, parsed_string, sizeof(parsed_string), 0);
            if (include_cgi(parsed_string, r) == -1) {
                ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                            "invalid CGI ref \"%s\" in %s", tag_val, file);
                ap_rputs(error, r);
            }
            /* grumble groan */
#ifndef WIN32
            ap_chdir_file(r->filename);
#endif
        }
        else if (!strcmp(tag, "done")) {
            return 0;
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                        "unknown parameter \"%s\" to tag exec in %s",
                        tag, file);
            ap_rputs(error, r);
        }
    }

}

static int handle_echo(FILE *in, request_rec *r, const char *error)
{
    char tag[MAX_STRING_LEN];
    char *tag_val;

    while (1) {
        if (!(tag_val = get_tag(r->pool, in, tag, sizeof(tag), 1))) {
            return 1;
        }
        if (!strcmp(tag, "var")) {
            const char *val = ap_table_get(r->subprocess_env, tag_val);

            if (val) {
                ap_rputs(val, r);
            }
            else {
                ap_rputs("(none)", r);
            }
        }
        else if (!strcmp(tag, "done")) {
            return 0;
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                        "unknown parameter \"%s\" to tag echo in %s",
                        tag, r->filename);
            ap_rputs(error, r);
        }
    }
}

#ifdef USE_PERL_SSI
static int handle_perl(FILE *in, request_rec *r, const char *error)
{
    char tag[MAX_STRING_LEN];
    char parsed_string[MAX_STRING_LEN];
    char *tag_val;
    SV *sub = Nullsv;
    AV *av = newAV();

    if (!(ap_allow_options(r) & OPT_INCLUDES)) {
        ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                    "httpd: #perl SSI disallowed by IncludesNoExec in %s",
                    r->filename);
        return DECLINED;
    }
    while (1) {
        if (!(tag_val = get_tag(r->pool, in, tag, sizeof(tag), 1))) {
            break;
        }
        if (strnEQ(tag, "sub", 3)) {
            sub = newSVpv(tag_val, 0);
        }
        else if (strnEQ(tag, "arg", 3)) {
            parse_string(r, tag_val, parsed_string, sizeof(parsed_string), 0);
            av_push(av, newSVpv(parsed_string, 0));
        }
        else if (strnEQ(tag, "done", 4)) {
            break;
        }
    }
    perl_stdout2client(r);
    perl_setup_env(r);
    perl_call_handler(sub, r, av);
    return OK;
}
#endif

/* error and tf must point to a string with room for at 
 * least MAX_STRING_LEN characters 
 */
static int handle_config(FILE *in, request_rec *r, char *error, char *tf,
                         int *sizefmt)
{
    char tag[MAX_STRING_LEN];
    char *tag_val;
    char parsed_string[MAX_STRING_LEN];
    table *env = r->subprocess_env;

    while (1) {
        if (!(tag_val = get_tag(r->pool, in, tag, sizeof(tag), 0))) {
            return 1;
        }
        if (!strcmp(tag, "errmsg")) {
            parse_string(r, tag_val, error, MAX_STRING_LEN, 0);
        }
        else if (!strcmp(tag, "timefmt")) {
            time_t date = r->request_time;

            parse_string(r, tag_val, tf, MAX_STRING_LEN, 0);
            ap_table_setn(env, "DATE_LOCAL", ap_ht_time(r->pool, date, tf, 0));
            ap_table_setn(env, "DATE_GMT", ap_ht_time(r->pool, date, tf, 1));
            ap_table_setn(env, "LAST_MODIFIED",
                      ap_ht_time(r->pool, r->finfo.st_mtime, tf, 0));
        }
        else if (!strcmp(tag, "sizefmt")) {
            parse_string(r, tag_val, parsed_string, sizeof(parsed_string), 0);
            decodehtml(parsed_string);
            if (!strcmp(parsed_string, "bytes")) {
                *sizefmt = SIZEFMT_BYTES;
            }
            else if (!strcmp(parsed_string, "abbrev")) {
                *sizefmt = SIZEFMT_KMG;
            }
        }
        else if (!strcmp(tag, "done")) {
            return 0;
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                        "unknown parameter \"%s\" to tag config in %s",
                        tag, r->filename);
            ap_rputs(error, r);
        }
    }
}


static int find_file(request_rec *r, const char *directive, const char *tag,
                     char *tag_val, struct stat *finfo, const char *error)
{
    char *to_send;
    request_rec *rr;
    int ret=0;

    if (!strcmp(tag, "file")) {
        ap_getparents(tag_val);    /* get rid of any nasties */
        
        rr = ap_sub_req_lookup_file(tag_val, r);

        if (rr->status == HTTP_OK && rr->finfo.st_mode != 0) {
            to_send = rr->filename;
            if ((ret = stat(to_send, finfo)) == -1) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                            "unable to get information about \"%s\" "
                            "in parsed file %s",
                            to_send, r->filename);
                ap_rputs(error, r);
            }
        }
        else {
            ret = -1;
            ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                        "unable to lookup information about \"%s\" "
                        "in parsed file %s",
                        tag_val, r->filename);
            ap_rputs(error, r);
        }
        
        ap_destroy_sub_req(rr);
        
        return ret;
    }
    else if (!strcmp(tag, "virtual")) {
        rr = ap_sub_req_lookup_uri(tag_val, r);

        if (rr->status == HTTP_OK && rr->finfo.st_mode != 0) {
            memcpy((char *) finfo, (const char *) &rr->finfo,
                   sizeof(struct stat));
            ap_destroy_sub_req(rr);
            return 0;
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                        "unable to get information about \"%s\" "
                        "in parsed file %s",
                        tag_val, r->filename);
            ap_rputs(error, r);
            ap_destroy_sub_req(rr);
            return -1;
        }
    }
    else {
        ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                    "unknown parameter \"%s\" to tag %s in %s",
                    tag, directive, r->filename);
        ap_rputs(error, r);
        return -1;
    }
}


static int handle_fsize(FILE *in, request_rec *r, const char *error, int sizefmt)
{
    char tag[MAX_STRING_LEN];
    char *tag_val;
    struct stat finfo;
    char parsed_string[MAX_STRING_LEN];

    while (1) {
        if (!(tag_val = get_tag(r->pool, in, tag, sizeof(tag), 1))) {
            return 1;
        }
        else if (!strcmp(tag, "done")) {
            return 0;
        }
        else {
            parse_string(r, tag_val, parsed_string, sizeof(parsed_string), 0);
            if (!find_file(r, "fsize", tag, parsed_string, &finfo, error)) {
                if (sizefmt == SIZEFMT_KMG) {
                    ap_send_size(finfo.st_size, r);
                }
                else {
                    int l, x;
#if defined(BSD) && BSD > 199305
                    /* ap_snprintf can't handle %qd */
                    sprintf(tag, "%qd", finfo.st_size);
#else
                    ap_snprintf(tag, sizeof(tag), "%ld", finfo.st_size);
#endif
                    l = strlen(tag);    /* grrr */
                    for (x = 0; x < l; x++) {
                        if (x && (!((l - x) % 3))) {
                            ap_rputc(',', r);
                        }
                        ap_rputc(tag[x], r);
                    }
                }
            }
        }
    }
}

static int handle_flastmod(FILE *in, request_rec *r, const char *error, const char *tf)
{
    char tag[MAX_STRING_LEN];
    char *tag_val;
    struct stat finfo;
    char parsed_string[MAX_STRING_LEN];

    while (1) {
        if (!(tag_val = get_tag(r->pool, in, tag, sizeof(tag), 1))) {
            return 1;
        }
        else if (!strcmp(tag, "done")) {
            return 0;
        }
        else {
            parse_string(r, tag_val, parsed_string, sizeof(parsed_string), 0);
            if (!find_file(r, "flastmod", tag, parsed_string, &finfo, error)) {
                ap_rputs(ap_ht_time(r->pool, finfo.st_mtime, tf, 0), r);
            }
        }
    }
}

static int re_check(request_rec *r, char *string, char *rexp)
{
    regex_t *compiled;
    int regex_error;

    compiled = ap_pregcomp(r->pool, rexp, REG_EXTENDED | REG_NOSUB);
    if (compiled == NULL) {
        ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                    "unable to compile pattern \"%s\"", rexp);
        return -1;
    }
    regex_error = regexec(compiled, string, 0, (regmatch_t *) NULL, 0);
    ap_pregfree(r->pool, compiled);
    return (!regex_error);
}

enum token_type {
    token_string,
    token_and, token_or, token_not, token_eq, token_ne,
    token_rbrace, token_lbrace, token_group,
    token_ge, token_le, token_gt, token_lt
};
struct token {
    enum token_type type;
    char value[MAX_STRING_LEN];
};

/* there is an implicit assumption here that string is at most MAX_STRING_LEN-1
 * characters long...
 */
static const char *get_ptoken(request_rec *r, const char *string, struct token *token)
{
    char ch;
    int next = 0;
    int qs = 0;

    /* Skip leading white space */
    if (string == (char *) NULL) {
        return (char *) NULL;
    }
    while ((ch = *string++)) {
        if (!ap_isspace(ch)) {
            break;
        }
    }
    if (ch == '\0') {
        return (char *) NULL;
    }

    token->type = token_string; /* the default type */
    switch (ch) {
    case '(':
        token->type = token_lbrace;
        return (string);
    case ')':
        token->type = token_rbrace;
        return (string);
    case '=':
        token->type = token_eq;
        return (string);
    case '!':
        if (*string == '=') {
            token->type = token_ne;
            return (string + 1);
        }
        else {
            token->type = token_not;
            return (string);
        }
    case '\'':
        token->type = token_string;
        qs = 1;
        break;
    case '|':
        if (*string == '|') {
            token->type = token_or;
            return (string + 1);
        }
        break;
    case '&':
        if (*string == '&') {
            token->type = token_and;
            return (string + 1);
        }
        break;
    case '>':
        if (*string == '=') {
            token->type = token_ge;
            return (string + 1);
        }
        else {
            token->type = token_gt;
            return (string);
        }
    case '<':
        if (*string == '=') {
            token->type = token_le;
            return (string + 1);
        }
        else {
            token->type = token_lt;
            return (string);
        }
    default:
        token->type = token_string;
        break;
    }
    /* We should only be here if we are in a string */
    if (!qs) {
        token->value[next++] = ch;
    }

    /* 
     * Yes I know that goto's are BAD.  But, c doesn't allow me to
     * exit a loop from a switch statement.  Yes, I could use a flag,
     * but that is (IMHO) even less readable/maintainable than the goto.
     */
    /* 
     * I used the ++string throughout this section so that string
     * ends up pointing to the next token and I can just return it
     */
    for (ch = *string; ch != '\0'; ch = *++string) {
        if (ch == '\\') {
            if ((ch = *++string) == '\0') {
                goto TOKEN_DONE;
            }
            token->value[next++] = ch;
            continue;
        }
        if (!qs) {
            if (ap_isspace(ch)) {
                goto TOKEN_DONE;
            }
            switch (ch) {
            case '(':
                goto TOKEN_DONE;
            case ')':
                goto TOKEN_DONE;
            case '=':
                goto TOKEN_DONE;
            case '!':
                goto TOKEN_DONE;
            case '|':
                if (*(string + 1) == '|') {
                    goto TOKEN_DONE;
                }