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Diffstat (limited to 'modules/metadata/mod_version.c')
| -rw-r--r-- | modules/metadata/mod_version.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/modules/metadata/mod_version.c b/modules/metadata/mod_version.c new file mode 100644 index 0000000..688cd8d --- /dev/null +++ b/modules/metadata/mod_version.c @@ -0,0 +1,313 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* + * mod_version.c + * Allow conditional configuration depending on the httpd version + * + * André Malo (nd/perlig.de), January 2004 + * + * Some stuff coded here is heavily based on the core <IfModule> + * containers. + * + * The module makes the following confgurations possible: + * + * <IfVersion op major.minor.patch> + * # conditional config here ... + *</IfVersion> + * + * where "op" is one of: + * = / == equal + * > greater than + * >= greater or equal + * < less than + * <= less or equal + * + * If minor version and patch level are omitted they are assumed to be 0. + * + * Alternatively you can match the whole version (including some vendor-added + * string of the CORE version, see ap_release.h) against a regular expression: + * + * <IfVersion op regex> + * # conditional config here ... + *</IfVersion> + * + * where "op" is one of: + * = / == match; regex must be surrounded by slashes + * ~ match; regex MAY NOT be surrounded by slashes + * + * Note that all operators may be preceded by an exclamation mark + * (without spaces) in order to reverse their meaning. + * + */ + +#include "apr.h" +#include "apr_strings.h" +#include "apr_lib.h" + +#include "httpd.h" +#include "http_config.h" +#include "http_log.h" + + +/* module structure */ +module AP_MODULE_DECLARE_DATA version_module; + +/* queried httpd version */ +static ap_version_t httpd_version; + + +/* + * compare the supplied version with the core one + */ +static int compare_version(char *version_string, const char **error) +{ + char *p = version_string, *ep; + int version[3] = {0, 0, 0}; + int c = 0; + + *error = "Version appears to be invalid. It must have the format " + "major[.minor[.patch]] where major, minor and patch are " + "numbers."; + + if (!apr_isdigit(*p)) { + return 0; + } + + /* parse supplied version */ + ep = version_string + strlen(version_string); + while (p <= ep && c < 3) { + if (*p == '.') { + *p = '\0'; + } + + if (!*p) { + version[c++] = atoi(version_string); + version_string = ++p; + continue; + } + + if (!apr_isdigit(*p)) { + break; + } + + ++p; + } + + if (p < ep) { /* syntax error */ + return 0; + } + + *error = NULL; + + if (httpd_version.major > version[0]) { + return 1; + } + else if (httpd_version.major < version[0]) { + return -1; + } + else if (httpd_version.minor > version[1]) { + return 1; + } + else if (httpd_version.minor < version[1]) { + return -1; + } + else if (httpd_version.patch > version[2]) { + return 1; + } + else if (httpd_version.patch < version[2]) { + return -1; + } + + /* seems to be the same */ + return 0; +} + +/* + * match version against a regular expression + */ +static int match_version(apr_pool_t *pool, char *version_string, + const char **error) +{ + ap_regex_t *compiled; + const char *to_match; + int rc; + + compiled = ap_pregcomp(pool, version_string, AP_REG_EXTENDED); + if (!compiled) { + *error = "Unable to compile regular expression"; + return 0; + } + + *error = NULL; + + to_match = apr_psprintf(pool, "%d.%d.%d%s", + httpd_version.major, + httpd_version.minor, + httpd_version.patch, + httpd_version.add_string); + + rc = !ap_regexec(compiled, to_match, 0, NULL, 0); + + ap_pregfree(pool, compiled); + return rc; +} + +/* + * Implements the <IfVersion> container + */ +static const char *start_ifversion(cmd_parms *cmd, void *mconfig, + const char *arg1, const char *arg2, + const char *arg3) +{ + const char *endp; + int reverse = 0, done = 0, match = 0, compare; + const char *p, *error; + char c; + + /* supplying one argument is possible, we assume an equality check then */ + if (!arg2) { + arg2 = arg1; + arg1 = "="; + } + + /* surrounding quotes without operator */ + if (!arg3 && *arg2 == '>' && !arg2[1]) { + arg3 = ">"; + arg2 = arg1; + arg1 = "="; + } + + /* the third argument makes version surrounding quotes plus operator + * possible. + */ + endp = arg2 + strlen(arg2); + if ( endp == arg2 + || (!(arg3 && *arg3 == '>' && !arg3[1]) && *--endp != '>')) { + return apr_pstrcat(cmd->pool, cmd->cmd->name, + "> directive missing closing '>'", NULL); + } + + p = arg1; + if (*p == '!') { + reverse = 1; + if (p[1]) { + ++p; + } + } + + c = *p++; + if (!*p || (*p == '=' && !p[1] && c != '~')) { + if (!httpd_version.major) { + ap_get_server_revision(&httpd_version); + } + + done = 1; + switch (c) { + case '=': + /* normal comparison */ + if (*arg2 != '/') { + compare = compare_version(apr_pstrmemdup(cmd->temp_pool, arg2, + endp-arg2), + &error); + if (error) { + return error; + } + + match = !compare; + break; + } + + /* regexp otherwise */ + if (endp == ++arg2 || *--endp != '/') { + return "Missing delimiting / of regular expression."; + } + + case '~': + /* regular expression */ + match = match_version(cmd->temp_pool, + apr_pstrmemdup(cmd->temp_pool, arg2, + endp-arg2), + &error); + if (error) { + return error; + } + break; + + case '<': + compare = compare_version(apr_pstrmemdup(cmd->temp_pool, arg2, + endp-arg2), + &error); + if (error) { + return error; + } + + match = ((-1 == compare) || (*p && !compare)); + break; + + case '>': + compare = compare_version(apr_pstrmemdup(cmd->temp_pool, arg2, + endp-arg2), + &error); + if (error) { + return error; + } + + match = ((1 == compare) || (*p && !compare)); + break; + + default: + done = 0; + break; + } + } + + if (!done) { + return apr_pstrcat(cmd->pool, "unrecognized operator '", arg1, "'", + NULL); + } + + if ((!reverse && match) || (reverse && !match)) { + ap_directive_t *parent = NULL; + ap_directive_t *current = NULL; + const char *retval; + + retval = ap_build_cont_config(cmd->pool, cmd->temp_pool, cmd, + ¤t, &parent, "<IfVersion"); + *(ap_directive_t **)mconfig = current; + return retval; + } + + *(ap_directive_t **)mconfig = NULL; + return ap_soak_end_container(cmd, "<IfVersion"); +} + +static const command_rec version_cmds[] = { + AP_INIT_TAKE123("<IfVersion", start_ifversion, NULL, EXEC_ON_READ | OR_ALL, + "a comparison operator, a version (and a delimiter)"), + { NULL } +}; + +AP_DECLARE_MODULE(version) = +{ + STANDARD20_MODULE_STUFF, + NULL, /* dir config creater */ + NULL, /* dir merger --- default is to override */ + NULL, /* server config */ + NULL, /* merge server configs */ + version_cmds, /* command apr_table_t */ + NULL, /* register hooks */ +}; |