static cond_result_t config_check_cond_nocache(server *srv, connection *con, data_config *dc) {
buffer *l;
server_socket *srv_sock = con->srv_socket;
/* check parent first */
if (dc->parent && dc->parent->context_ndx) {
/**
* a nested conditional
*
* if the parent is not decided yet or false, we can't be true either
*/
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "sb", "go parent", dc->parent->key);
}
switch (config_check_cond_cached(srv, con, dc->parent)) {
case COND_RESULT_FALSE:
return COND_RESULT_FALSE;
case COND_RESULT_UNSET:
return COND_RESULT_UNSET;
default:
break;
}
}
if (dc->prev) {
/**
* a else branch
*
* we can only be executed, if all of our previous brothers
* are false
*/
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "sb", "go prev", dc->prev->key);
}
/* make sure prev is checked first */
config_check_cond_cached(srv, con, dc->prev);
/* one of prev set me to FALSE */
switch (con->cond_cache[dc->context_ndx].result) {
case COND_RESULT_FALSE:
return con->cond_cache[dc->context_ndx].result;
default:
break;
}
}
if (!con->conditional_is_valid[dc->comp]) {
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "dss",
dc->comp,
dc->key->ptr,
con->conditional_is_valid[dc->comp] ? "yeah" : "nej");
}
return COND_RESULT_UNSET;
}
/* pass the rules */
switch (dc->comp) {
case COMP_HTTP_HOST: {
char *ck_colon = NULL, *val_colon = NULL;
if (!buffer_string_is_empty(con->uri.authority)) {
/*
* append server-port to the HTTP_POST if necessary
*/
l = con->uri.authority;
switch(dc->cond) {
case CONFIG_COND_NE:
case CONFIG_COND_EQ:
ck_colon = strchr(dc->string->ptr, ':');
val_colon = strchr(l->ptr, ':');
if (NULL != ck_colon && NULL == val_colon) {
/* condition "host:port" but client send "host" */
buffer_copy_buffer(srv->cond_check_buf, l);
buffer_append_string_len(srv->cond_check_buf, CONST_STR_LEN(":"));
buffer_append_int(srv->cond_check_buf, sock_addr_get_port(&(srv_sock->addr)));
l = srv->cond_check_buf;
} else if (NULL != val_colon && NULL == ck_colon) {
/* condition "host" but client send "host:port" */
buffer_copy_string_len(srv->cond_check_buf, l->ptr, val_colon - l->ptr);
l = srv->cond_check_buf;
}
break;
default:
break;
}
#if defined USE_OPENSSL && ! defined OPENSSL_NO_TLSEXT
} else if (!buffer_string_is_empty(con->tlsext_server_name)) {
l = con->tlsext_server_name;
#endif
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_REMOTE_IP: {
char *nm_slash;
/* handle remoteip limitations
*
* "10.0.0.1" is provided for all comparisions
*
* only for == and != we support
*
* "10.0.0.1/24"
*/
if ((dc->cond == CONFIG_COND_EQ ||
dc->cond == CONFIG_COND_NE) &&
(con->dst_addr.plain.sa_family == AF_INET) &&
(NULL != (nm_slash = strchr(dc->string->ptr, '/')))) {
int nm_bits;
long nm;
char *err;
struct in_addr val_inp;
if (*(nm_slash+1) == '\0') {
log_error_write(srv, __FILE__, __LINE__, "sb", "ERROR: no number after / ", dc->string);
return COND_RESULT_FALSE;
}
nm_bits = strtol(nm_slash + 1, &err, 10);
if (*err) {
log_error_write(srv, __FILE__, __LINE__, "sbs", "ERROR: non-digit found in netmask:", dc->string, err);
return COND_RESULT_FALSE;
}
if (nm_bits > 32 || nm_bits < 0) {
log_error_write(srv, __FILE__, __LINE__, "sbs", "ERROR: invalid netmask:", dc->string, err);
return COND_RESULT_FALSE;
}
/* take IP convert to the native */
buffer_copy_string_len(srv->cond_check_buf, dc->string->ptr, nm_slash - dc->string->ptr);
#ifdef __WIN32
if (INADDR_NONE == (val_inp.s_addr = inet_addr(srv->cond_check_buf->ptr))) {
log_error_write(srv, __FILE__, __LINE__, "sb", "ERROR: ip addr is invalid:", srv->cond_check_buf);
return COND_RESULT_FALSE;
}
#else
if (0 == inet_aton(srv->cond_check_buf->ptr, &val_inp)) {
log_error_write(srv, __FILE__, __LINE__, "sb", "ERROR: ip addr is invalid:", srv->cond_check_buf);
return COND_RESULT_FALSE;
}
#endif
/* build netmask */
nm = nm_bits ? htonl(~((1 << (32 - nm_bits)) - 1)) : 0;
if ((val_inp.s_addr & nm) == (con->dst_addr.ipv4.sin_addr.s_addr & nm)) {
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_TRUE : COND_RESULT_FALSE;
} else {
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_FALSE : COND_RESULT_TRUE;
}
} else {
l = con->dst_addr_buf;
}
break;
}
case COMP_HTTP_SCHEME:
l = con->uri.scheme;
break;
case COMP_HTTP_URL:
l = con->uri.path;
break;
case COMP_HTTP_QUERY_STRING:
l = con->uri.query;
break;
case COMP_SERVER_SOCKET:
l = srv_sock->srv_token;
break;
case COMP_HTTP_REFERER: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Referer"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_COOKIE: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Cookie"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_USER_AGENT: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "User-Agent"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_REQUEST_METHOD: {
const char *method = get_http_method_name(con->request.http_method);
/* we only have the request method as const char but we need a buffer for comparing */
buffer_copy_string(srv->tmp_buf, method);
l = srv->tmp_buf;
break;
}
case COMP_HTTP_LANGUAGE: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Accept-Language"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
default:
return COND_RESULT_FALSE;
}
if (NULL == l) {
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "bsbs", dc->comp_key,
"(", l, ") compare to NULL");
}
return COND_RESULT_FALSE;
}
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "bsbsb", dc->comp_key,
"(", l, ") compare to ", dc->string);
}
switch(dc->cond) {
case CONFIG_COND_NE:
case CONFIG_COND_EQ:
if (buffer_is_equal(l, dc->string)) {
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_TRUE : COND_RESULT_FALSE;
} else {
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_FALSE : COND_RESULT_TRUE;
}
break;
#ifdef HAVE_PCRE_H
case CONFIG_COND_NOMATCH:
case CONFIG_COND_MATCH: {
cond_cache_t *cache = &con->cond_cache[dc->context_ndx];
int n;
#ifndef elementsof
#define elementsof(x) (sizeof(x) / sizeof(x[0]))
#endif
n = pcre_exec(dc->regex, dc->regex_study, CONST_BUF_LEN(l), 0, 0,
cache->matches, elementsof(cache->matches));
cache->patterncount = n;
if (n > 0) {
cache->comp_value = l;
cache->comp_type = dc->comp;
return (dc->cond == CONFIG_COND_MATCH) ? COND_RESULT_TRUE : COND_RESULT_FALSE;
} else {
/* cache is already cleared */
return (dc->cond == CONFIG_COND_MATCH) ? COND_RESULT_FALSE : COND_RESULT_TRUE;
}
break;
}
#endif
default:
/* no way */
break;
}
return COND_RESULT_FALSE;
}
int config_check_cond(server *srv, connection *con, data_config *dc) {
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "s", "=== start of condition block ===");
}
return (config_check_cond_cached(srv, con, dc) == COND_RESULT_TRUE);
}
static cond_result_t config_check_cond_nocache(server *srv, connection *con, data_config *dc) {
buffer *l;
server_socket *srv_sock = con->srv_socket; //socket 插座、接口
/* check parent first */
if (dc->parent && dc->parent->context_ndx) { //如果父节点存在，但父节点未被判断或父节点是错误的，那么子节点也不能进行判断或子节点是错误的
/**
* a nested conditional
*
* if the parent is not decided yet or false, we can't be true either
*/
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "sb", "go parent", dc->parent->key);
}
switch (config_check_cond_cached(srv, con, dc->parent)) {
case COND_RESULT_FALSE:
return COND_RESULT_FALSE;
case COND_RESULT_UNSET:
return COND_RESULT_UNSET;
default:
break;
}
}
if (dc->prev) {
/**
* a else branch
*
* we can only be executed, if all of our previous brothers
* are false
*/
//存在前驱块，那么需要先判断前驱块状态
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "sb", "go prev", dc->prev->key);
}
/* make sure prev is checked first */
config_check_cond_cached(srv, con, dc->prev);
/* one of prev set me to FALSE */
//在判断前驱块状态时候有可能就已经设置了本快的状态（config_check_cond_cached函数调用如前驱块为真，该前驱块以下的块将全都设置为假），如果为假则直接返回。
switch (con->cond_cache[dc->context_ndx].result) {
case COND_RESULT_FALSE:
return con->cond_cache[dc->context_ndx].result;
default:
break;
}
}
if (!con->conditional_is_valid[dc->comp]) {
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "dss",
dc->comp,
dc->key->ptr,
con->conditional_is_valid[dc->comp] ? "yeah" : "nej");
}
return COND_RESULT_UNSET;
}
/* pass the rules */
//开始实际的连接状态判断，Lighttpd1.4.20提供的条件配置有10个，分别为server_socket HTTP_URL HTTP_HOST HTTP_REFERER HTTP_USER_AGENT HTTP_COOKIE
//HTTP_REMOTE_IP HTTP_QUERY_STRING HTTP_SCHEME HTTP_REQUEST_METHOD
switch (dc->comp) {
case COMP_HTTP_HOST: {
char *ck_colon = NULL, *val_colon = NULL;
if (!buffer_is_empty(con->uri.authority)) { //authority内保存是请求连接的Host信息（可能是域名也可能是IP地址）
/*
* append server-port to the HTTP_POST if necessary
*/
l = con->uri.authority;
switch(dc->cond) {
case CONFIG_COND_NE:
case CONFIG_COND_EQ:
ck_colon = strchr(dc->string->ptr, ':');
val_colon = strchr(l->ptr, ':');
if (ck_colon == val_colon) { //请求连接的Host信息与条件配置块的Host条件设置格式一致（即两者都包含有端口号或都没有包含端口号），则什么都不做。
/* nothing to do with it */
break;
}
if (ck_colon) { //请求连接的Host信息没有半酣端口号而条件配置块的Host包含端口号，因此给请求连接的Host加上端口号
/* condition "host:port" but client send "host" */
buffer_copy_string_buffer(srv->cond_check_buf, l);
buffer_append_string_len(srv->cond_check_buf, CONST_STR_LEN(":"));
buffer_append_long(srv->cond_check_buf, sock_addr_get_port(&(srv_sock->addr)));
l = srv->cond_check_buf;
} else if (!ck_colon) { //请求连接的Host信息包含端口号而条件配置信息块的Host没有包含端口号，因此将请求连接Host的端口号去掉。
/* condition "host" but client send "host:port" */
buffer_copy_string_len(srv->cond_check_buf, l->ptr, val_colon - l->ptr);
l = srv->cond_check_buf;
}
break;
default:
break;
}
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_REMOTE_IP: { //REMOTE adj 遥远的
char *nm_slash;
/* handle remoteip limitations
*
* "10.0.0.1" is provided for all comparisions
*
* only for == and != we support
*
* "10.0.0.1/24"
*/
if ((dc->cond == CONFIG_COND_EQ ||
dc->cond == CONFIG_COND_NE) &&
(con->dst_addr.plain.sa_family == AF_INET) &&
(NULL != (nm_slash = strchr(dc->string->ptr, '/')))) {
int nm_bits;
long nm;
char *err;
struct in_addr val_inp;
if (*(nm_slash+1) == '\0') { //无分类域间路由选择CIDR(CIDR记法，斜线记法)，这里对CIDR格式字符串进行检验
log_error_write(srv, __FILE__, __LINE__, "sb", "ERROR: no number after / ", dc->string); //CIDR格式不对，缺少表示网络前缀位数的数字
return COND_RESULT_FALSE;
}
/*
函数strtol()声明在头文件stdlib.h内，原型为long int strtol(const char *nptr,char **endptr,int base);用于将参数nptr字符串根据
base指定的进制转换成对应的长整型数。参数base范围从2至36，或0（即默认采用十进制做转换，但遇到如'0x'前置字符则会使用十六进制做转换）。
strtol()会扫描参数nptr字符串，跳过前面的空格字符，知道遇上数字或正负号才开始做转换，在遇到非数字或字符串结束时('\0')结束转换，并将结果返回。
若参数endptr不为NULL，则会将不符合调节而终止的nptr中的字符指针由endptr返回。该函数执行成功返回转换后的长整型数，否则返回ERANGE(表示指定的专函字符串超出合法范围)
并将错误代码存入errno中，此处用于获取端口十进制的整型数。
*/
nm_bits = strtol(nm_slash + 1, &err, 10);
if (*err) {
log_error_write(srv, __FILE__, __LINE__, "sbs", "ERROR: non-digit found in netmask:", dc->string, err);
return COND_RESULT_FALSE;
}
/* take IP convert to the native */
buffer_copy_string_len(srv->cond_check_buf, dc->string->ptr, nm_slash - dc->string->ptr);
#ifdef __WIN32
if (INADDR_NONE == (val_inp.s_addr = inet_addr(srv->cond_check_buf->ptr))) {
log_error_write(srv, __FILE__, __LINE__, "sb", "ERROR: ip addr is invalid:", srv->cond_check_buf);
return COND_RESULT_FALSE;
}
#else
/*
函数inet_ston()声明在头文件sys/scoket.h内，原型为int inet_aton(const char *cp,struct in_addr *inp); 用于将参数cp所指的字符串形式的网络地址
转换成网络地址成网络使用的二进制数形式，然后存于参数inp所指的in_addr结构中。
*/
if (0 == inet_aton(srv->cond_check_buf->ptr, &val_inp)) {
log_error_write(srv, __FILE__, __LINE__, "sb", "ERROR: ip addr is invalid:", srv->cond_check_buf);
return COND_RESULT_FALSE;
}
#endif
/* build netmask */
/*
函数htonl()声明在头文件srpa/inet.h内，原型为unint32_t htonl(uint32_t hostlong); 用来将参数hostlong指定的32位无符号长整型由主机字节顺序转换成网络字符顺序。
*/
nm = htonl(~((1 << (32 - nm_bits)) - 1));
if ((val_inp.s_addr & nm) == (con->dst_addr.ipv4.sin_addr.s_addr & nm)) { //当前连接的客户端IP地址与条件配置信息块的条件设置匹配，按需返回结果
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_TRUE : COND_RESULT_FALSE;
} else { //不匹配
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_FALSE : COND_RESULT_TRUE;
}
} else {
l = con->dst_addr_buf;
}
break;
}
case COMP_HTTP_SCHEME:
l = con->uri.scheme;
break;
case COMP_HTTP_URL:
l = con->uri.path;
break;
case COMP_HTTP_QUERY_STRING:
l = con->uri.query;
break;
case COMP_SERVER_SOCKET:
l = srv_sock->srv_token;
break;
case COMP_HTTP_REFERER: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Referer"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_COOKIE: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Cookie"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_USER_AGENT: {
data_string *ds;
if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "User-Agent"))) {
l = ds->value;
} else {
l = srv->empty_string;
}
break;
}
case COMP_HTTP_REQUEST_METHOD: {
/*
get_http_method_name()函数根据当前连接的请求方法（通过分析请求行得知）返回对应的字符串，比如"GET"、"POST"等
*/
const char *method = get_http_method_name(con->request.http_method);
/* we only have the request method as const char but we need a buffer for comparing */
//为了后面的统一匹配比较，利用该字符串初始化buffer结构体。
buffer_copy_string(srv->tmp_buf, method);
l = srv->tmp_buf;
break;
}
default:
return COND_RESULT_FALSE;
}
if (NULL == l) { //当前连接匹配字段为空，则返回假
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "bsbs", dc->comp_key,
"(", l, ") compare to NULL");
}
return COND_RESULT_FALSE;
}
if (con->conf.log_condition_handling) {
log_error_write(srv, __FILE__, __LINE__, "bsbsb", dc->comp_key,
"(", l, ") compare to ", dc->string);
}
switch(dc->cond) {
case CONFIG_COND_NE:
case CONFIG_COND_EQ:
if (buffer_is_equal(l, dc->string)) { //相等或不等匹配
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_TRUE : COND_RESULT_FALSE;
} else {
return (dc->cond == CONFIG_COND_EQ) ? COND_RESULT_FALSE : COND_RESULT_TRUE;
}
break;
#ifdef HAVE_PCRE_H
/*
正则式匹配需要相应库的支持，GNU/Linux下有两套正则式编程支持库：POSIX库和PCRE库，POSIX库不需要单独安装，能满足一般需求，但是速度稍慢些，
读者查看MAN手册。PCRE库久负盛名，功能强大，匹配速度快，但是可能需要单独安装。关于PCRE库的更多介绍，读者可以查阅站点：http://www.pcre.org/。
此处用的是PCRE库。
*/
case CONFIG_COND_NOMATCH:
case CONFIG_COND_MATCH: {
cond_cache_t *cache = &con->cond_cache[dc->context_ndx];
int n;
#ifndef elementsof
#define elementsof(x) (sizeof(x) / sizeof(x[0]))
#endif
n = pcre_exec(dc->regex, dc->regex_study, l->ptr, l->used - 1, 0, 0,
cache->matches, elementsof(cache->matches)); //利用PCRE库函数pcre_exec()执行匹配操作，如果不匹配或执行出错则返回一个负值（其中，不匹配则返回PCRE_ERROR_NOMATCH(该宏值为-1)），
//如果匹配成功将返回一个正数。关于函数pcre_exec()的详细说明可以参考说明文档：http://www.pcre.org/prce.txt.
cache->patterncount = n;
if (n > 0) { //匹配成功
cache->comp_value = l;
cache->comp_type = dc->comp;
return (dc->cond == CONFIG_COND_MATCH) ? COND_RESULT_TRUE : COND_RESULT_FALSE;
} else {
/* cache is already cleared */
return (dc->cond == CONFIG_COND_MATCH) ? COND_RESULT_FALSE : COND_RESULT_TRUE;
}
break;
}
#endif
default:
/* no way */
break;
}
return COND_RESULT_FALSE;
}