OCT 1.更换通过pcap生成过滤器方式

depend/third_libs.cmake

@@ -4,6 +4,7 @@ INCLUDE(FetchContent)
 PKG_SEARCH_MODULE(LIBCURL REQUIRED libcurl)
 PKG_SEARCH_MODULE(LIBSSL REQUIRED libssl)
 PKG_SEARCH_MODULE(LIBCRYPTO REQUIRED libcrypto)
+PKG_SEARCH_MODULE(LIBPCAP REQUIRED libpcap)
 
 IF (USED_SQLITE AND (NOT USED_SQLITE_CRYPTO))
     PKG_SEARCH_MODULE(LIBSQLITE3 REQUIRED sqlite3)
@@ -20,6 +21,7 @@ IF ((NOT LIBCRYPTO_FOUND) OR (NOT LIBSSL_FOUND) OR (NOT LIBCURL_FOUND))
 ENDIF ()
 
 LIST(APPEND COMMON_LIBS "${LIBCURL_LDFLAGS} ${LIBSSL_LDFLAGS} ${LIBCRYPTO_LDFLAGS} ${LIBSQLITE3_LDFLAGS}")
+LIST(APPEND COMMON_LIBS "${LIBPCAP_LDFLAGS}")
 LIST(APPEND COMMON_LIBS "${LIBZMQ_LDFLAGS}")
 LIST(APPEND COMMON_LIBS "-lm -lpthread")
 

srcs/service/dhcpd/dhcpd_network.c

@@ -10,6 +10,7 @@
 #include <net/if.h>
 #include <sys/socket.h>
 #include <sys/mman.h>
+#include <pcap/pcap.h>
 
 #include "service/dhcpd.h"
 #include "user_errno.h"
@@ -28,6 +29,7 @@
 #define MAX_DHCP_PKG_SIZE (512)
 #define VLAN_VNI_ID(x)    ntohs((x))
 #define DHCP_XID(x)       ntohl((x))
+#define MAXIMUM_SNAPLEN	  (262144)
 
 #define MAC_TO_STR(mac, str) \
     sprintf(str, "%02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5])
@@ -96,12 +98,6 @@ responsible for relaying broadcast DHCP traffic (DISCOVERY and SOLICIT
 messages) originating within their racks to anycast VIPs, one DHCPv4 and one
 for DHCPv6.
 */
-#define USED_DEFAULT_BPF (1)
-
-#ifndef USED_DEFAULT_BPF
-#include "packet_filter.h"
-extern struct sock_fprog bpf;
-#endif
 
 #ifdef USED_DEFAULT_BPF
 static struct sock_filter g_filterCode[] = {
@@ -216,13 +212,9 @@ static struct sock_filter g_filterCode[] = {
     {0x6,  0,  0,  0x00000000},
  // endregion
 };
-
-static struct sock_fprog bpf = {
-    .len    = sizeof(g_filterCode) / (sizeof(struct sock_filter)),
-    .filter = g_filterCode,
-};
 #endif
 
+static struct sock_fprog bpf;
 static PACKET_MMAP_RING  g_pkgRing;
 static NIC_INFO          g_nicInfo;
 static uv_udp_t          g_uvRawSockReq;
@@ -696,6 +688,32 @@ static void socket_send_task(uv_timer_t *UNUSED(pArg)) {
     }
 }
 
+void init_filter() {
+#ifdef USED_DEFAULT_BPF
+    bpf.len    = sizeof(g_filterCode) / (sizeof(struct sock_filter));
+    bpf.filter = g_filterCode;
+#else
+    static pcap_t *pd;
+    pd = pcap_open_dead(DLT_EN10MB, MAXIMUM_SNAPLEN);
+
+    struct bpf_program fcode;
+    char *cmd_buf = "vlan and udp and port 67 and port 68";
+    pcap_compile(pd, &fcode, cmd_buf, 1, 0);
+
+    struct bpf_insn *insn = fcode.bf_insns;
+    struct sock_filter *g_filters = (struct sock_filter *)malloc(fcode.bf_len * sizeof (struct sock_filter));
+    for (int i = 0; i < fcode.bf_len; ++insn, ++i){
+        g_filters[i].code = insn->code;
+        g_filters[i].jt   = insn->jt;
+        g_filters[i].jf   = insn->jf;
+        g_filters[i].k    = insn->k;
+    }
+
+    bpf.len    = fcode.bf_len;
+    bpf.filter = g_filters;
+#endif
+}
+
 int dhcpd_init() {
     static uv_poll_t  uvSocket;
     static uv_timer_t uvTm;
@@ -708,13 +726,7 @@ int dhcpd_init() {
 
     get_nic_info(g_nicInfo.pIfName, &g_nicInfo.ipAddr, &g_nicInfo.netmask, NULL, g_nicInfo.macAddr);
 
-    #ifndef USED_DEFAULT_BPF
+    init_filter();
-    ret = init_filter();
-    if(ret != ERR_SUCCESS) {
-        LOG_MOD(error, ZLOG_MOD_DHCPD, "Create packet filter Error\n");
-        return ret;
-    }
-    #endif
 
     ret = create_udp_socket();
     if (ret != ERR_SUCCESS) {

srcs/service/dhcpd/include/packet_filter.h

@@ -1,15 +0,0 @@
-//
-// Created by dongwenzhe on 2023/4/14.
-//
-#ifndef VCPE_PACKET_FILTER_H
-#define VCPE_PACKET_FILTER_H
-
-typedef enum {
-    CODE_VAL = 0,
-    JT_VAL,
-    JF_VAL,
-} FILTER_PARAM;
-
-int init_filter();
-
-#endif //VCPE_PACKET_FILTER_H

srcs/service/dhcpd/packet_filter.c

@@ -1,111 +0,0 @@
-//
-// Created by dongwenzhe on 2023/4/14.
-//
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <linux/filter.h>
-#include "common.h"
-#include "packet_filter.h"
-#include "user_errno.h"
-
-const char        *cmd_get_filter = "tcpdump \"vlan and udp and port 67 and port 68\" -dd";
-int                filter_num = 0;
-struct sock_fprog  bpf;
-struct sock_filter g_filterCode[256];
-
-int tolower(int c) {
-    if (c >= 'A' && c <= 'Z') {
-        return (c + 'a' - 'A');
-    } else {
-        return c;
-    }
-}
-
-int hex_to_int(char s[]) {
-    int i = 0;
-    int n = 0;
-
-    while(s[i] == ' ') {
-        i++;
-    }
-    if (s[i] == '0' && (s[i+1]=='x'||s[i+1]=='X')){
-        i = i + 2;
-    }
-    for (; (s[i] >= '0' && s[i] <= '9') || (s[i] >= 'a' && s[i] <= 'z') || (s[i] >='A' && s[i] <= 'Z');++i)
-    {
-        if (tolower(s[i]) > '9') {
-            n = 16*n + (10 + tolower(s[i]) - 'a');
-        } else {
-            n = 16*n + (tolower(s[i]) - '0');
-        }
-    }
-    return n;
-}
-
-int init_filter() {
-    FILE        *pFile  = NULL;
-    unsigned int rdSize = 0;
-    char        *pOut;
-
-    pFile = popen(cmd_get_filter, "r");
-    if (pFile == NULL) {
-        return ERR_OPEN_FILE;
-    }
-
-    pOut = (char *)malloc(4096);
-    rdSize = fread(pOut, sizeof(char), 4096, pFile);
-    if(rdSize <= 0) {
-        return ERR_READ_FILE;
-    }
-
-    for(int i = 0; i < strlen(pOut); i++) {
-        // read a new array
-        if (pOut[i] == '{') {
-            __u16 code;
-            __u8  jt, jf;
-            __u32 k;
-            int   val_flag = 0;
-            i++;
-
-            // end of the array
-            while (pOut[i] != '}') {
-                char t_val[256];
-                int  j = 0;
-                // read the value in array
-                while (pOut[i] != ',' && pOut[i] != '}') {
-                    t_val[j] = pOut[i];
-                    i++;
-                    j++;
-                }
-                // whether the read is a valid string
-                if(j != 0){
-                    t_val[j] = '\0';
-                    //printf("%s\n", t_val);
-                    // write in socket_filter
-                    if (val_flag == CODE_VAL) {
-                        g_filterCode[filter_num].code = (__u16)hex_to_int(t_val);
-                    } else if (val_flag == JT_VAL) {
-                        g_filterCode[filter_num].jt = (__u8)atoi(t_val);
-                    } else if (val_flag == JF_VAL) {
-                        g_filterCode[filter_num].jf = (__u8)atoi(t_val);
-                    } else {
-                        g_filterCode[filter_num].k = (__u32)hex_to_int(t_val);
-                    }
-                    val_flag = (val_flag + 1)%4;
-                } else {
-                    i++;
-                }
-            }
-            filter_num++;
-        }
-    }
-    bpf.len = filter_num;
-    bpf.filter = g_filterCode;
-
-    free(pOut);
-    pclose(pFile);
-
-    return ERR_SUCCESS;
-}
-