core/ngx_inet.c源文件分析
本节我们主要分析一下nginx网络地址相关操作。
1. 相关静态函数声明
/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
//解析Unix域url地址
static ngx_int_t ngx_parse_unix_domain_url(ngx_pool_t *pool, ngx_url_t *u);
//解析ipv4类型url地址
static ngx_int_t ngx_parse_inet_url(ngx_pool_t *pool, ngx_url_t *u);
//解析ipv6类型url地址
static ngx_int_t ngx_parse_inet6_url(ngx_pool_t *pool, ngx_url_t *u);2. 函数ngx_inet_addr()
in_addr_t
ngx_inet_addr(u_char *text, size_t len)
{
u_char *p, c;
in_addr_t addr;
ngx_uint_t octet, n;
addr = 0;
octet = 0;
n = 0;
for (p = text; p < text + len; p++) {
c = *p;
if (c >= '0' && c <= '9') {
octet = octet * 10 + (c - '0');
if (octet > 255) {
return INADDR_NONE;
}
continue;
}
if (c == '.') {
addr = (addr << 8) + octet;
octet = 0;
n++;
continue;
}
return INADDR_NONE;
}
if (n == 3) {
addr = (addr << 8) + octet;
return htonl(addr);
}
return INADDR_NONE;
}此函数用于将字符串表示形式的IPv4地址转换成in_addr_t表示形式。转换出错，返回INADDR_NONE。
2. 函数ngx_inet6_addr()
#if (NGX_HAVE_INET6)
ngx_int_t
ngx_inet6_addr(u_char *p, size_t len, u_char *addr)
{
u_char c, *zero, *digit, *s, *d;
size_t len4;
ngx_uint_t n, nibbles, word;
if (len == 0) {
return NGX_ERROR;
}
zero = NULL;
digit = NULL;
len4 = 0;
nibbles = 0;
word = 0;
n = 8;
if (p[0] == ':') {
p++;
len--;
}
for (/* void */; len; len--) {
c = *p++;
if (c == ':') {
if (nibbles) {
digit = p;
len4 = len;
*addr++ = (u_char) (word >> 8);
*addr++ = (u_char) (word & 0xff);
if (--n) {
nibbles = 0;
word = 0;
continue;
}
} else {
if (zero == NULL) {
digit = p;
len4 = len;
zero = addr;
continue;
}
}
return NGX_ERROR;
}
if (c == '.' && nibbles) {
if (n < 2 || digit == NULL) {
return NGX_ERROR;
}
word = ngx_inet_addr(digit, len4 - 1);
if (word == INADDR_NONE) {
return NGX_ERROR;
}
word = ntohl(word);
*addr++ = (u_char) ((word >> 24) & 0xff);
*addr++ = (u_char) ((word >> 16) & 0xff);
n--;
break;
}
if (++nibbles > 4) {
return NGX_ERROR;
}
if (c >= '0' && c <= '9') {
word = word * 16 + (c - '0');
continue;
}
c |= 0x20;
if (c >= 'a' && c <= 'f') {
word = word * 16 + (c - 'a') + 10;
continue;
}
return NGX_ERROR;
}
if (nibbles == 0 && zero == NULL) {
return NGX_ERROR;
}
*addr++ = (u_char) (word >> 8);
*addr++ = (u_char) (word & 0xff);
if (--n) {
if (zero) {
n *= 2;
s = addr - 1;
d = s + n;
while (s >= zero) {
*d-- = *s--;
}
ngx_memzero(zero, n);
return NGX_OK;
}
} else {
if (zero == NULL) {
return NGX_OK;
}
}
return NGX_ERROR;
}
#endif这里我们暂不支持NGX_HAVE_INET6，函数ngx_inet6_addr()用于将字符串表示形式的IPv6地址转换成128bit位的地址。IPv6地址的表示形式一般为：
2001:0410:0000:1234:FB00:1400:5000:45FF //首选格式 2001:0410 :: 1234:FB00:1400:5000:45FF //压缩格式(注意压缩格式中，只能有一个地方压缩） 0:0:0:0:0:0:138.1.1.1 //内嵌IPv4
下面我们来详细介绍一下ngx_inet6_addr():
ngx_int_t
ngx_inet6_addr(u_char *p, size_t len, u_char *addr)
{
zero = NULL; //用于记录IPv6中压缩格式出现的位置
digit = NULL; //用于记录一个段中数据出现的起始位置
len4 = 0; //用于记录从当前位置到结束位置的长度（主要是处理内嵌IPv4这一情况)
nibbles = 0; //主要是用于记录一个段的长度（例如上述首选格式，分成8个段，每段长度为4)
word = 0; //主要用于处理每一个段的转换
n = 8; //IPv6最长有8个段
//1) 跳过最前面的压缩
if (p[0] == ':') {
p++;
len--;
}
for (/* void */; len; len--) {
c = *p++;
//2) 检测完了一段
if(c == ':')
{
if(nibbles)
{
//2.1) 将该段进行转换
//2.2) 判断IPv6最长只能为8段
}
else{
//2.3 记录压缩段的开始
}
}
if (c == '.' && nibbles) {
{
//3) 处理IPv6中内嵌IPv4的情况
}
//4) 转换一个段中的16进制数据
}
if (nibbles == 0 && zero == NULL) {
return NGX_ERROR;
}
//5) 转换最后一个段
*addr++ = (u_char) (word >> 8);
*addr++ = (u_char) (word & 0xff);
//6) 处理有压缩情况下的填充（最终要填充到128bit)
}3. 函数ngx_sock_ntop()
size_t
ngx_sock_ntop(struct sockaddr *sa, socklen_t socklen, u_char *text, size_t len,
ngx_uint_t port)
{
u_char *p;
struct sockaddr_in *sin;
#if (NGX_HAVE_INET6)
size_t n;
struct sockaddr_in6 *sin6;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
struct sockaddr_un *saun;
#endif
switch (sa->sa_family) {
case AF_INET:
sin = (struct sockaddr_in *) sa;
p = (u_char *) &sin->sin_addr;
if (port) {
p = ngx_snprintf(text, len, "%ud.%ud.%ud.%ud:%d",
p[0], p[1], p[2], p[3], ntohs(sin->sin_port));
} else {
p = ngx_snprintf(text, len, "%ud.%ud.%ud.%ud",
p[0], p[1], p[2], p[3]);
}
return (p - text);
#if (NGX_HAVE_INET6)
case AF_INET6:
sin6 = (struct sockaddr_in6 *) sa;
n = 0;
if (port) {
text[n++] = '[';
}
n = ngx_inet6_ntop(sin6->sin6_addr.s6_addr, &text[n], len);
if (port) {
n = ngx_sprintf(&text[1 + n], "]:%d",
ntohs(sin6->sin6_port)) - text;
}
return n;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
case AF_UNIX:
saun = (struct sockaddr_un *) sa;
/* on Linux sockaddr might not include sun_path at all */
if (socklen <= (socklen_t) offsetof(struct sockaddr_un, sun_path)) {
p = ngx_snprintf(text, len, "unix:%Z");
} else {
p = ngx_snprintf(text, len, "unix:%s%Z", saun->sun_path);
}
/* we do not include trailing zero in address length */
return (p - text - 1);
#endif
default:
return 0;
}
}本函数用于将sockaddr表示形式的地址（IPv4/IPv6/Unix Domain)，转换成字符串表示形式。（注意：这里如果地址是IPv4/IPv6,也会对port参数进行转换）
4. 函数ngx_inet_ntop()
size_t
ngx_inet_ntop(int family, void *addr, u_char *text, size_t len)
{
u_char *p;
switch (family) {
case AF_INET:
p = addr;
return ngx_snprintf(text, len, "%ud.%ud.%ud.%ud",
p[0], p[1], p[2], p[3])
- text;
#if (NGX_HAVE_INET6)
case AF_INET6:
return ngx_inet6_ntop(addr, text, len);
#endif
default:
return 0;
}
}这里对IPv4/IPv6地址转换成字符串表示形式。
5. 函数ngx_inet_ntop()
#if (NGX_HAVE_INET6)
size_t
ngx_inet6_ntop(u_char *p, u_char *text, size_t len)
{
u_char *dst;
size_t max, n;
ngx_uint_t i, zero, last;
if (len < NGX_INET6_ADDRSTRLEN) {
return 0;
}
zero = (ngx_uint_t) -1;
last = (ngx_uint_t) -1;
max = 1;
n = 0;
for (i = 0; i < 16; i += 2) {
if (p[i] || p[i + 1]) {
if (max < n) {
zero = last;
max = n;
}
n = 0;
continue;
}
if (n++ == 0) {
last = i;
}
}
if (max < n) {
zero = last;
max = n;
}
dst = text;
n = 16;
if (zero == 0) {
if ((max == 5 && p[10] == 0xff && p[11] == 0xff)
|| (max == 6)
|| (max == 7 && p[14] != 0 && p[15] != 1))
{
n = 12;
}
*dst++ = ':';
}
for (i = 0; i < n; i += 2) {
if (i == zero) {
*dst++ = ':';
i += (max - 1) * 2;
continue;
}
dst = ngx_sprintf(dst, "%xd", p[i] * 256 + p[i + 1]);
if (i < 14) {
*dst++ = ':';
}
}
if (n == 12) {
dst = ngx_sprintf(dst, "%ud.%ud.%ud.%ud", p[12], p[13], p[14], p[15]);
}
return dst - text;
}
#endif这里对128bit的IPv6地址转换成IPv6字符串表示形式。下面详细介绍一下该函数：
size_t
ngx_inet6_ntop(u_char *p, u_char *text, size_t len)
{
//1) IPv6地址总共16个字节，每2个字节一组，找出最长连续为0的组，
// 用zero变量记录该组的起始位置，用max记录连续为0的组数目
//2) 如果最长连续为0的组在头部（即zero==0)，则进一步判断是否是内嵌IPv4
//3) 将每一组转换成IPv6字符串表示形式
for (i = 0; i < n; i += 2) {
if (i == zero) {
*dst++ = ':';
i += (max - 1) * 2;
continue;
}
dst = ngx_sprintf(dst, "%xd", p[i] * 256 + p[i + 1]);
if (i < 14) {
*dst++ = ':';
}
}
//4) 处理内嵌IPv4情况
}6. 函数ngx_ptocidr()
ngx_int_t
ngx_ptocidr(ngx_str_t *text, ngx_cidr_t *cidr)
{
u_char *addr, *mask, *last;
size_t len;
ngx_int_t shift;
#if (NGX_HAVE_INET6)
ngx_int_t rc;
ngx_uint_t s, i;
#endif
addr = text->data;
last = addr + text->len;
mask = ngx_strlchr(addr, last, '/');
len = (mask ? mask : last) - addr;
cidr->u.in.addr = ngx_inet_addr(addr, len);
if (cidr->u.in.addr != INADDR_NONE) {
cidr->family = AF_INET;
if (mask == NULL) {
cidr->u.in.mask = 0xffffffff;
return NGX_OK;
}
#if (NGX_HAVE_INET6)
} else if (ngx_inet6_addr(addr, len, cidr->u.in6.addr.s6_addr) == NGX_OK) {
cidr->family = AF_INET6;
if (mask == NULL) {
ngx_memset(cidr->u.in6.mask.s6_addr, 0xff, 16);
return NGX_OK;
}
#endif
} else {
return NGX_ERROR;
}
mask++;
shift = ngx_atoi(mask, last - mask);
if (shift == NGX_ERROR) {
return NGX_ERROR;
}
switch (cidr->family) {
#if (NGX_HAVE_INET6)
case AF_INET6:
if (shift > 128) {
return NGX_ERROR;
}
addr = cidr->u.in6.addr.s6_addr;
mask = cidr->u.in6.mask.s6_addr;
rc = NGX_OK;
for (i = 0; i < 16; i++) {
s = (shift > 8) ? 8 : shift;
shift -= s;
mask[i] = (u_char) (0xffu << (8 - s));
if (addr[i] != (addr[i] & mask[i])) {
rc = NGX_DONE;
addr[i] &= mask[i];
}
}
return rc;
#endif
default: /* AF_INET */
if (shift > 32) {
return NGX_ERROR;
}
if (shift) {
cidr->u.in.mask = htonl((uint32_t) (0xffffffffu << (32 - shift)));
} else {
/* x86 compilers use a shl instruction that shifts by modulo 32 */
cidr->u.in.mask = 0;
}
if (cidr->u.in.addr == (cidr->u.in.addr & cidr->u.in.mask)) {
return NGX_OK;
}
cidr->u.in.addr &= cidr->u.in.mask;
return NGX_DONE;
}
}本函数用于将字符串转换成无类域间路由。该函数实现较为简单，我们简单介绍一下：
ngx_int_t
ngx_ptocidr(ngx_str_t *text, ngx_cidr_t *cidr)
{
//1) 找出无类域间路由中"/"的位置，例如222.80.18.18/25， 该32bit地址中前25位为网络
// 部分，后7位为主机部分。
//2) 解析"/"前面部分的IP地址，是属于IPv4还是IPv6类型
//3) 分别计算出IPv4/IPv6无类域间路由的“网络部分”（addr）及“掩码部分”(mask)
}7. 函数ngx_parse_addr()
ngx_int_t
ngx_parse_addr(ngx_pool_t *pool, ngx_addr_t *addr, u_char *text, size_t len)
{
in_addr_t inaddr;
ngx_uint_t family;
struct sockaddr_in *sin;
#if (NGX_HAVE_INET6)
struct in6_addr inaddr6;
struct sockaddr_in6 *sin6;
/*
* prevent MSVC8 warning:
* potentially uninitialized local variable 'inaddr6' used
*/
ngx_memzero(&inaddr6, sizeof(struct in6_addr));
#endif
inaddr = ngx_inet_addr(text, len);
if (inaddr != INADDR_NONE) {
family = AF_INET;
len = sizeof(struct sockaddr_in);
#if (NGX_HAVE_INET6)
} else if (ngx_inet6_addr(text, len, inaddr6.s6_addr) == NGX_OK) {
family = AF_INET6;
len = sizeof(struct sockaddr_in6);
#endif
} else {
return NGX_DECLINED;
}
addr->sockaddr = ngx_pcalloc(pool, len);
if (addr->sockaddr == NULL) {
return NGX_ERROR;
}
addr->sockaddr->sa_family = (u_char) family;
addr->socklen = len;
switch (family) {
#if (NGX_HAVE_INET6)
case AF_INET6:
sin6 = (struct sockaddr_in6 *) addr->sockaddr;
ngx_memcpy(sin6->sin6_addr.s6_addr, inaddr6.s6_addr, 16);
break;
#endif
default: /* AF_INET */
sin = (struct sockaddr_in *) addr->sockaddr;
sin->sin_addr.s_addr = inaddr;
break;
}
return NGX_OK;
}本函数用于将字符串表示的IPv4/IPv6地址转换成ngx_addr_t形式。
8. 函数ngx_parse_url()
ngx_int_t
ngx_parse_url(ngx_pool_t *pool, ngx_url_t *u)
{
u_char *p;
size_t len;
p = u->url.data;
len = u->url.len;
if (len >= 5 && ngx_strncasecmp(p, (u_char *) "unix:", 5) == 0) {
return ngx_parse_unix_domain_url(pool, u);
}
if (len && p[0] == '[') {
return ngx_parse_inet6_url(pool, u);
}
return ngx_parse_inet_url(pool, u);
}本函数用于解析url，分三种类型：
-
unix域URL: 调用ngx_parse_unix_domain_url()，例如
unix:/var/run/nginx.sock -
IPv6 URL: 调用ngx_parse_inet6_url()，例如
[::1]:5353 -
IPv4 URL: 调用ngx_parse_inet_url()，例如
127.0.0.1:12345
9. 函数ngx_parse_unix_domain_url()
static ngx_int_t
ngx_parse_unix_domain_url(ngx_pool_t *pool, ngx_url_t *u)
{
#if (NGX_HAVE_UNIX_DOMAIN)
u_char *path, *uri, *last;
size_t len;
struct sockaddr_un *saun;
len = u->url.len;
path = u->url.data;
path += 5;
len -= 5;
if (u->uri_part) {
last = path + len;
uri = ngx_strlchr(path, last, ':');
if (uri) {
len = uri - path;
uri++;
u->uri.len = last - uri;
u->uri.data = uri;
}
}
if (len == 0) {
u->err = "no path in the unix domain socket";
return NGX_ERROR;
}
u->host.len = len++;
u->host.data = path;
if (len > sizeof(saun->sun_path)) {
u->err = "too long path in the unix domain socket";
return NGX_ERROR;
}
u->socklen = sizeof(struct sockaddr_un);
saun = (struct sockaddr_un *) &u->sockaddr;
saun->sun_family = AF_UNIX;
(void) ngx_cpystrn((u_char *) saun->sun_path, path, len);
u->addrs = ngx_pcalloc(pool, sizeof(ngx_addr_t));
if (u->addrs == NULL) {
return NGX_ERROR;
}
saun = ngx_pcalloc(pool, sizeof(struct sockaddr_un));
if (saun == NULL) {
return NGX_ERROR;
}
u->family = AF_UNIX;
u->naddrs = 1;
saun->sun_family = AF_UNIX;
(void) ngx_cpystrn((u_char *) saun->sun_path, path, len);
u->addrs[0].sockaddr = (struct sockaddr *) saun;
u->addrs[0].socklen = sizeof(struct sockaddr_un);
u->addrs[0].name.len = len + 4;
u->addrs[0].name.data = u->url.data;
return NGX_OK;
#else
u->err = "the unix domain sockets are not supported on this platform";
return NGX_ERROR;
#endif
}本函数用于解析ngx_url_t.url，主要会解析成以下几个部分：
-
ngx_url_t.uri: 如果url中uri部分存在的话，解析后存放于此 -
ngx_url_t.host: 解析后的主机名存放于此 -
ngx_url_t.sockaddr: 解析后的字符串表示形式 -
ngx_url_t.addrs: 解析后的地址
9. 函数ngx_parse_inet_url()
static ngx_int_t
ngx_parse_inet_url(ngx_pool_t *pool, ngx_url_t *u)
{
u_char *p, *host, *port, *last, *uri, *args;
size_t len;
ngx_int_t n;
struct sockaddr_in *sin;
#if (NGX_HAVE_INET6)
struct sockaddr_in6 *sin6;
#endif
u->socklen = sizeof(struct sockaddr_in);
sin = (struct sockaddr_in *) &u->sockaddr;
sin->sin_family = AF_INET;
u->family = AF_INET;
host = u->url.data;
last = host + u->url.len;
port = ngx_strlchr(host, last, ':');
uri = ngx_strlchr(host, last, '/');
args = ngx_strlchr(host, last, '?');
if (args) {
if (uri == NULL || args < uri) {
uri = args;
}
}
if (uri) {
if (u->listen || !u->uri_part) {
u->err = "invalid host";
return NGX_ERROR;
}
u->uri.len = last - uri;
u->uri.data = uri;
last = uri;
if (uri < port) {
port = NULL;
}
}
if (port) {
port++;
len = last - port;
n = ngx_atoi(port, len);
if (n < 1 || n > 65535) {
u->err = "invalid port";
return NGX_ERROR;
}
u->port = (in_port_t) n;
sin->sin_port = htons((in_port_t) n);
u->port_text.len = len;
u->port_text.data = port;
last = port - 1;
} else {
if (uri == NULL) {
if (u->listen) {
/* test value as port only */
n = ngx_atoi(host, last - host);
if (n != NGX_ERROR) {
if (n < 1 || n > 65535) {
u->err = "invalid port";
return NGX_ERROR;
}
u->port = (in_port_t) n;
sin->sin_port = htons((in_port_t) n);
u->port_text.len = last - host;
u->port_text.data = host;
u->wildcard = 1;
return NGX_OK;
}
}
}
u->no_port = 1;
u->port = u->default_port;
sin->sin_port = htons(u->default_port);
}
len = last - host;
if (len == 0) {
u->err = "no host";
return NGX_ERROR;
}
u->host.len = len;
u->host.data = host;
if (u->listen && len == 1 && *host == '*') {
sin->sin_addr.s_addr = INADDR_ANY;
u->wildcard = 1;
return NGX_OK;
}
sin->sin_addr.s_addr = ngx_inet_addr(host, len);
if (sin->sin_addr.s_addr != INADDR_NONE) {
if (sin->sin_addr.s_addr == INADDR_ANY) {
u->wildcard = 1;
}
u->naddrs = 1;
u->addrs = ngx_pcalloc(pool, sizeof(ngx_addr_t));
if (u->addrs == NULL) {
return NGX_ERROR;
}
sin = ngx_pcalloc(pool, sizeof(struct sockaddr_in));
if (sin == NULL) {
return NGX_ERROR;
}
ngx_memcpy(sin, u->sockaddr, sizeof(struct sockaddr_in));
u->addrs[0].sockaddr = (struct sockaddr *) sin;
u->addrs[0].socklen = sizeof(struct sockaddr_in);
p = ngx_pnalloc(pool, u->host.len + sizeof(":65535") - 1);
if (p == NULL) {
return NGX_ERROR;
}
u->addrs[0].name.len = ngx_sprintf(p, "%V:%d",
&u->host, u->port) - p;
u->addrs[0].name.data = p;
return NGX_OK;
}
if (u->no_resolve) {
return NGX_OK;
}
if (ngx_inet_resolve_host(pool, u) != NGX_OK) {
return NGX_ERROR;
}
u->family = u->addrs[0].sockaddr->sa_family;
u->socklen = u->addrs[0].socklen;
ngx_memcpy(u->sockaddr, u->addrs[0].sockaddr, u->addrs[0].socklen);
switch (u->family) {
#if (NGX_HAVE_INET6)
case AF_INET6:
sin6 = (struct sockaddr_in6 *) &u->sockaddr;
if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
u->wildcard = 1;
}
break;
#endif
default: /* AF_INET */
sin = (struct sockaddr_in *) &u->sockaddr;
if (sin->sin_addr.s_addr == INADDR_ANY) {
u->wildcard = 1;
}
break;
}
return NGX_OK;
}本函数用于解析IPv4类型的URL。例如：
localhost:8088/query?id=1001 listen 8000;
下面我们就来简要分析一下该函数：
static ngx_int_t
ngx_parse_inet_url(ngx_pool_t *pool, ngx_url_t *u)
{
//1) 找出port, uri以及args字段的起始位置
//2) 解析uri
//3) 解析port: 这里如果url中本身携带有port，则直接转换； 否则进行如下解析：
// 若uri为NULL并且u->listen为1(即类似于listen 8000)，调用ngx_atoi()进行转换；
// 否则设置u->no_port=1， 然后采用默认的端口
//4) 转换u->host部分： 如果host直接是ip地址表示形式，可以直接转换；否则
//调用ngx_inet_resolve_host()进行域名解析
}10. 函数ngx_parse_inet6_url()
static ngx_int_t
ngx_parse_inet6_url(ngx_pool_t *pool, ngx_url_t *u)
{
#if (NGX_HAVE_INET6)
u_char *p, *host, *port, *last, *uri;
size_t len;
ngx_int_t n;
struct sockaddr_in6 *sin6;
u->socklen = sizeof(struct sockaddr_in6);
sin6 = (struct sockaddr_in6 *) &u->sockaddr;
sin6->sin6_family = AF_INET6;
host = u->url.data + 1;
last = u->url.data + u->url.len;
p = ngx_strlchr(host, last, ']');
if (p == NULL) {
u->err = "invalid host";
return NGX_ERROR;
}
if (last - p) {
port = p + 1;
uri = ngx_strlchr(port, last, '/');
if (uri) {
if (u->listen || !u->uri_part) {
u->err = "invalid host";
return NGX_ERROR;
}
u->uri.len = last - uri;
u->uri.data = uri;
last = uri;
}
if (*port == ':') {
port++;
len = last - port;
n = ngx_atoi(port, len);
if (n < 1 || n > 65535) {
u->err = "invalid port";
return NGX_ERROR;
}
u->port = (in_port_t) n;
sin6->sin6_port = htons((in_port_t) n);
u->port_text.len = len;
u->port_text.data = port;
} else {
u->no_port = 1;
u->port = u->default_port;
sin6->sin6_port = htons(u->default_port);
}
}
len = p - host;
if (len == 0) {
u->err = "no host";
return NGX_ERROR;
}
u->host.len = len + 2;
u->host.data = host - 1;
if (ngx_inet6_addr(host, len, sin6->sin6_addr.s6_addr) != NGX_OK) {
u->err = "invalid IPv6 address";
return NGX_ERROR;
}
if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
u->wildcard = 1;
}
u->family = AF_INET6;
u->naddrs = 1;
u->addrs = ngx_pcalloc(pool, sizeof(ngx_addr_t));
if (u->addrs == NULL) {
return NGX_ERROR;
}
sin6 = ngx_pcalloc(pool, sizeof(struct sockaddr_in6));
if (sin6 == NULL) {
return NGX_ERROR;
}
ngx_memcpy(sin6, u->sockaddr, sizeof(struct sockaddr_in6));
u->addrs[0].sockaddr = (struct sockaddr *) sin6;
u->addrs[0].socklen = sizeof(struct sockaddr_in6);
p = ngx_pnalloc(pool, u->host.len + sizeof(":65535") - 1);
if (p == NULL) {
return NGX_ERROR;
}
u->addrs[0].name.len = ngx_sprintf(p, "%V:%d",
&u->host, u->port) - p;
u->addrs[0].name.data = p;
return NGX_OK;
#else
u->err = "the INET6 sockets are not supported on this platform";
return NGX_ERROR;
#endif
}本函数用于解析IPv6形式的Url。首先我们给出一个IPv6形式的url的例子：
listen [::1]:12345
下面我们再来简要分析一下本函数：
static ngx_int_t
ngx_parse_inet6_url(ngx_pool_t *pool, ngx_url_t *u)
{
//1) IPv6形式的url以“["开始，首先分析出其中的uri, port
//2) 转换IPv6的host部分
}11. 函数ngx_inet_resolve_host()
#if (NGX_HAVE_GETADDRINFO && NGX_HAVE_INET6)
ngx_int_t
ngx_inet_resolve_host(ngx_pool_t *pool, ngx_url_t *u)
{
u_char *p, *host;
size_t len;
in_port_t port;
ngx_uint_t i;
struct addrinfo hints, *res, *rp;
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
port = htons(u->port);
host = ngx_alloc(u->host.len + 1, pool->log);
if (host == NULL) {
return NGX_ERROR;
}
(void) ngx_cpystrn(host, u->host.data, u->host.len + 1);
ngx_memzero(&hints, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
#ifdef AI_ADDRCONFIG
hints.ai_flags = AI_ADDRCONFIG;
#endif
if (getaddrinfo((char *) host, NULL, &hints, &res) != 0) {
u->err = "host not found";
ngx_free(host);
return NGX_ERROR;
}
ngx_free(host);
for (i = 0, rp = res; rp != NULL; rp = rp->ai_next) {
switch (rp->ai_family) {
case AF_INET:
case AF_INET6:
break;
default:
continue;
}
i++;
}
if (i == 0) {
u->err = "host not found";
goto failed;
}
/* MP: ngx_shared_palloc() */
u->addrs = ngx_pcalloc(pool, i * sizeof(ngx_addr_t));
if (u->addrs == NULL) {
goto failed;
}
u->naddrs = i;
i = 0;
/* AF_INET addresses first */
for (rp = res; rp != NULL; rp = rp->ai_next) {
if (rp->ai_family != AF_INET) {
continue;
}
sin = ngx_pcalloc(pool, rp->ai_addrlen);
if (sin == NULL) {
goto failed;
}
ngx_memcpy(sin, rp->ai_addr, rp->ai_addrlen);
sin->sin_port = port;
u->addrs[i].sockaddr = (struct sockaddr *) sin;
u->addrs[i].socklen = rp->ai_addrlen;
len = NGX_INET_ADDRSTRLEN + sizeof(":65535") - 1;
p = ngx_pnalloc(pool, len);
if (p == NULL) {
goto failed;
}
len = ngx_sock_ntop((struct sockaddr *) sin, rp->ai_addrlen, p, len, 1);
u->addrs[i].name.len = len;
u->addrs[i].name.data = p;
i++;
}
for (rp = res; rp != NULL; rp = rp->ai_next) {
if (rp->ai_family != AF_INET6) {
continue;
}
sin6 = ngx_pcalloc(pool, rp->ai_addrlen);
if (sin6 == NULL) {
goto failed;
}
ngx_memcpy(sin6, rp->ai_addr, rp->ai_addrlen);
sin6->sin6_port = port;
u->addrs[i].sockaddr = (struct sockaddr *) sin6;
u->addrs[i].socklen = rp->ai_addrlen;
len = NGX_INET6_ADDRSTRLEN + sizeof("[]:65535") - 1;
p = ngx_pnalloc(pool, len);
if (p == NULL) {
goto failed;
}
len = ngx_sock_ntop((struct sockaddr *) sin6, rp->ai_addrlen, p,
len, 1);
u->addrs[i].name.len = len;
u->addrs[i].name.data = p;
i++;
}
freeaddrinfo(res);
return NGX_OK;
failed:
freeaddrinfo(res);
return NGX_ERROR;
}
#else /* !NGX_HAVE_GETADDRINFO || !NGX_HAVE_INET6 */
ngx_int_t
ngx_inet_resolve_host(ngx_pool_t *pool, ngx_url_t *u)
{
u_char *p, *host;
size_t len;
in_port_t port;
in_addr_t in_addr;
ngx_uint_t i;
struct hostent *h;
struct sockaddr_in *sin;
/* AF_INET only */
port = htons(u->port);
in_addr = ngx_inet_addr(u->host.data, u->host.len);
if (in_addr == INADDR_NONE) {
host = ngx_alloc(u->host.len + 1, pool->log);
if (host == NULL) {
return NGX_ERROR;
}
(void) ngx_cpystrn(host, u->host.data, u->host.len + 1);
h = gethostbyname((char *) host);
ngx_free(host);
if (h == NULL || h->h_addr_list[0] == NULL) {
u->err = "host not found";
return NGX_ERROR;
}
for (i = 0; h->h_addr_list[i] != NULL; i++) { /* void */ }
/* MP: ngx_shared_palloc() */
u->addrs = ngx_pcalloc(pool, i * sizeof(ngx_addr_t));
if (u->addrs == NULL) {
return NGX_ERROR;
}
u->naddrs = i;
for (i = 0; i < u->naddrs; i++) {
sin = ngx_pcalloc(pool, sizeof(struct sockaddr_in));
if (sin == NULL) {
return NGX_ERROR;
}
sin->sin_family = AF_INET;
sin->sin_port = port;
sin->sin_addr.s_addr = *(in_addr_t *) (h->h_addr_list[i]);
u->addrs[i].sockaddr = (struct sockaddr *) sin;
u->addrs[i].socklen = sizeof(struct sockaddr_in);
len = NGX_INET_ADDRSTRLEN + sizeof(":65535") - 1;
p = ngx_pnalloc(pool, len);
if (p == NULL) {
return NGX_ERROR;
}
len = ngx_sock_ntop((struct sockaddr *) sin,
sizeof(struct sockaddr_in), p, len, 1);
u->addrs[i].name.len = len;
u->addrs[i].name.data = p;
}
} else {
/* MP: ngx_shared_palloc() */
u->addrs = ngx_pcalloc(pool, sizeof(ngx_addr_t));
if (u->addrs == NULL) {
return NGX_ERROR;
}
sin = ngx_pcalloc(pool, sizeof(struct sockaddr_in));
if (sin == NULL) {
return NGX_ERROR;
}
u->naddrs = 1;
sin->sin_family = AF_INET;
sin->sin_port = port;
sin->sin_addr.s_addr = in_addr;
u->addrs[0].sockaddr = (struct sockaddr *) sin;
u->addrs[0].socklen = sizeof(struct sockaddr_in);
p = ngx_pnalloc(pool, u->host.len + sizeof(":65535") - 1);
if (p == NULL) {
return NGX_ERROR;
}
u->addrs[0].name.len = ngx_sprintf(p, "%V:%d",
&u->host, ntohs(port)) - p;
u->addrs[0].name.data = p;
}
return NGX_OK;
}
#endif /* NGX_HAVE_GETADDRINFO && NGX_HAVE_INET6 */本函数用于将主机名解析成url的IP地址。在objs/ngx_auto_config.h头文件中我们有如下定义：
#ifndef NGX_HAVE_GETADDRINFO #define NGX_HAVE_GETADDRINFO 1 #endif
但是当前并不支持NGX_HAVE_INET6。下面我们对该函数进行简要说明：
#if (NGX_HAVE_GETADDRINFO && NGX_HAVE_INET6)
ngx_int_t
ngx_inet_resolve_host(ngx_pool_t *pool, ngx_url_t *u)
{
//1) 调用getaddrinfo()解析主机名
//2) 对IPv4及IPv6形式的IP地址保存到ngx_url_t.addrs中
}
#else
ngx_int_t
ngx_inet_resolve_host(ngx_pool_t *pool, ngx_url_t *u)
{
// 1) 调用ngx_inet_addr()转换url中的Host主机
//2) 如果转换结果为INADDR_NONE，表明不知直接IPv4表示形式的主机，此时调用
// gethostbyname()函数来获得主机地址； 否则直接保存对应的ip即可
}
#endif12. 函数ngx_cmp_sockaddr()
ngx_int_t
ngx_cmp_sockaddr(struct sockaddr *sa1, socklen_t slen1,
struct sockaddr *sa2, socklen_t slen2, ngx_uint_t cmp_port)
{
struct sockaddr_in *sin1, *sin2;
#if (NGX_HAVE_INET6)
struct sockaddr_in6 *sin61, *sin62;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
size_t len;
struct sockaddr_un *saun1, *saun2;
#endif
if (sa1->sa_family != sa2->sa_family) {
return NGX_DECLINED;
}
switch (sa1->sa_family) {
#if (NGX_HAVE_INET6)
case AF_INET6:
sin61 = (struct sockaddr_in6 *) sa1;
sin62 = (struct sockaddr_in6 *) sa2;
if (cmp_port && sin61->sin6_port != sin62->sin6_port) {
return NGX_DECLINED;
}
if (ngx_memcmp(&sin61->sin6_addr, &sin62->sin6_addr, 16) != 0) {
return NGX_DECLINED;
}
break;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
case AF_UNIX:
saun1 = (struct sockaddr_un *) sa1;
saun2 = (struct sockaddr_un *) sa2;
if (slen1 < slen2) {
len = slen1 - offsetof(struct sockaddr_un, sun_path);
} else {
len = slen2 - offsetof(struct sockaddr_un, sun_path);
}
if (len > sizeof(saun1->sun_path)) {
len = sizeof(saun1->sun_path);
}
if (ngx_memcmp(&saun1->sun_path, &saun2->sun_path, len) != 0) {
return NGX_DECLINED;
}
break;
#endif
default: /* AF_INET */
sin1 = (struct sockaddr_in *) sa1;
sin2 = (struct sockaddr_in *) sa2;
if (cmp_port && sin1->sin_port != sin2->sin_port) {
return NGX_DECLINED;
}
if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr) {
return NGX_DECLINED;
}
break;
}
return NGX_OK;
}此函数用于比较两个socket地址是否相同。函数较为简单，这里不再进行细讲。
//IPv4形式的socket 地址 struct sockaddr_in *sin1, *sin2; //IPv6形式的socket 地址 struct sockaddr_in6 *sin61, *sin62; //unix域socket地址 struct sockaddr_un *saun1, *saun2;
[参看]
