nginx中判断输入ip是否和配置ip在同一个网段

根据input_ip & net_mask == seted_ip & net_mask 来判断。

详见代码：

typedef struct {
    ngx_uint_t         ip[4];
    ngx_uint_t         mask[4];
} ngx_stream_eth_netSegment_t;


typedef struct {
    ngx_array_t            eths; // ngx_streams_eth_srv_conf_t
} ngx_streams_eth_main_conf_t;


typedef struct {
    ngx_str_t         ethname;
    ngx_array_t     netSegments; // ngx_stream_eth_netSegment_t
} ngx_streams_eth_srv_conf_t ;

static ngx_int_t 
ngx_streams_eth_ip_atoi(ngx_str_t *ip, ngx_uint_t iparr[]) 
{
    int          i=0, j;
    u_char         *p, tmp[4]={0};
    int         cnt=0;
    ngx_int_t     len;
    
    p = ip->data;
    len = ip->len;

    for (j=0; j < len; j++) {
        if (*p == '.' || j == len - 1) { 
            if (j == len -1) {
                tmp[cnt++] = *p;
            }
            iparr[i++] = ngx_atoi(tmp, cnt);
            ngx_memset(tmp, 0, sizeof(tmp));
            cnt = 0;
            p++;
            continue;
        }
        tmp[cnt++] = *p++;
        if (cnt > 3) {
            return NGX_ERROR;
        }
    }

    
    return NGX_OK;
}


static ngx_int_t 
ngx_streams_eth_is_same_net(ngx_str_t *ip, ngx_stream_eth_netSegment_t *netSegment) 
{
    ngx_uint_t iparr[4]={0};
    ngx_int_t i;
    if (ngx_streams_eth_ip_atoi(ip, iparr) != NGX_OK) {
        return NGX_ERROR;
    }

    for (i=0; i<4; i++) {
        if ((iparr[i] & netSegment->mask[i]) != 
            (netSegment->ip[i] & netSegment->mask[i]) )  {
            return NGX_ERROR;
        }
    }
    return NGX_OK;    
}


ngx_stream_eth_netSegment_t * 
ngx_streams_eth_match(ngx_str_t *ip) {
    ngx_streams_eth_main_conf_t      *smcf;
    ngx_int_t                         i, j;
    ngx_streams_eth_srv_conf_t       *sscf;
    ngx_stream_eth_netSegment_t        *netSegment;
    
    smcf = ngx_streams_cycle_get_module_main_conf(ngx_cycle, ngx_streams_eth_module);
    for (i = 0; i < smcf->eths.nelts; i++) {
        sscf = ngx_array_pop(&smcf->eths, i);
        if (sscf == NULL) {
            goto failed;
        }
        for (j = 0; j < sscf->netSegments.nelts; j++) {
            netSegment = ngx_array_pop(&sscf->netSegments, j);
            if (ngx_streams_eth_is_same_net(ip, netSegment) == NGX_OK) {
                return netSegment;
            }
        }
    }

failed:
    return NULL;
}