优化以下程序：#includenetwork_protocolh 从配置文件中初始化接口参数 struct NetIf init_netifchar netif_cfg struct NetIf netif FILE f = fopenstrtrimnetif_cfg r; if f == NULL printf打开接口配置文件失败：sn netif_cfg;

以下是优化后的程序：

#include "network_protocol.h" /* 从配置文件中初始化接口参数 / struct NetIf init_netif(char netif_cfg, struct NetIf netif) { FILE *f = fopen(strtrim(netif_cfg), "r"); if (f == NULL) { printf("打开接口配置文件失败：%s\n", netif_cfg); return netif; } char str[100], *p = NULL; int loc[10], num, nifnum = 0; //伪接口 netif[0].ni_device = 0; netif[0].ni_ip = 0; netif[0].ni_mask = 0; memset(netif[0].ni_hwa, 0, ETH_ADDR_LEN); while (fgets(str, 100, f) != NULL) { strtrim(str);

    num = strsplit(str, ',', loc);
    if (num != 3) {
        printf("netif_cfg配置文件错误！\n");
        return netif;
    }
    nifnum++;
    netif[nifnum].ni_device = nifnum;
    netif[nifnum].ni_ip = str2ip(str);
    netif[nifnum].ni_mask = str2ip(str + loc[1]);
    p = str2hex(str + loc[2]);
    memcpy(netif[nifnum].ni_hwa, p, ETH_ADDR_LEN);
    free(p);
}
netif[nifnum + 1].ni_device = -1;
fclose(f);
return netif;

}

/* 删除路由表 */ void delete_routetable(struct Route *rtinfo){ struct Route *p; while(rtinfo != NULL){ p = rtinfo->rt_next; free(rtinfo); rtinfo = p; } }

/* 从配置文件中创建静态路由表 / struct Route init_routetable(char route_cfg, struct Route rtinfo) { char str[100]; int num, loc[10]; struct Route *p = NULL, *rt; uint32 ip, mask, maxnet, maxnif; FILE f = fopen(strtrim(route_cfg), "r"); if (f == NULL) { printf("打开接口配置文件失败%s\n", route_cfg); return rtinfo; } while (fgets(str, 100, f) != NULL) { strtrim(str); num = strsplit(str, ',', loc); if (num != 4) { printf("route_cfg配置文件错误！\n"); return rtinfo; } p = (struct Route)malloc(sizeof(struct Route)); p->rt_ifnum = -1; p->rt_net = str2ip(str); p->rt_mask = str2ip(str + loc[1]); p->rt_nexthop = str2ip(str + loc[2]); p->rt_distance = atoi(str+loc[3]); p->rt_next = rtinfo; rtinfo = p; } fclose(f); //路由下一跳ip对应的设备号 rt = rtinfo; while (rt != NULL) { maxnif = 0; maxnet = 0; for (int i = 1; netif[i].ni_device > 0; i++) { if ((rt->rt_nexthop & netif[i].ni_mask) == (netif[i].ni_ip & netif[i].ni_mask)) { //找到网络地址匹配最长的接口 if((rt->rt_nexthop & netif[i].ni_mask) >= maxnet){ maxnet = rt->rt_nexthop & netif[i].ni_mask; maxnif = i; } } } if(maxnif > 0) rt->rt_ifnum = maxnif; rt = rt->rt_next; } return rtinfo; }

/* 根据接口配置，更新路由表，以方便查询 / struct Route update_routetable(struct NetIf* netif, struct Route* rtinfo) { struct Route rt; uint32 ip, mask; //将127回环地址加入路由表 rt = (struct Route)malloc(sizeof(struct Route)); rt->rt_net = str2ip("127.0.0.0"); rt->rt_mask = htonl(0xff000000); rt->rt_ifnum = 0; rt->rt_nexthop = 0; rt->rt_distance = 0; rt->rt_next = rtinfo; //根据接口ip和mask添加路由，以方便查找 rtinfo = rt; for (int i = 1; netif[i].ni_device > 0; i++) { ip = netif[i].ni_ip; mask = netif[i].ni_mask; //将自己的ip加入路由表 rt = (struct Route*)malloc(sizeof(struct Route)); rt->rt_net = ip; rt->rt_mask = 0xffffffff; rt->rt_ifnum = 0; rt->rt_nexthop = 0; rt->rt_distance = 0; rt->rt_next = rtinfo; rtinfo = rt;

    //将自己的网络加入路由表
    rt = (struct Route*)malloc(sizeof(struct Route));
    rt->rt_net = ip & mask;
    rt->rt_mask = mask;
    rt->rt_ifnum = i;
    rt->rt_nexthop = 0;
    rt->rt_distance = 1;
    rt->rt_next = rtinfo;
    rtinfo = rt;

    //将自己的网络广播地址加入路由表
    rt = (struct Route*)malloc(sizeof(struct Route));
    rt->rt_net = (ip & mask) | (~mask);
    rt->rt_mask = 0xffffffff;
    rt->rt_ifnum = 0;
    rt->rt_distance = 0;
    rt->rt_nexthop = 0;
    rt->rt_next = rtinfo;
    rtinfo = rt;
}
return rtinfo;

}

/* 根据邻接路由信息，更新本地路由表 / struct Route adj_update_routetable(struct Route *rtinfo, struct Route *adj_rtinfo) { struct Route *res = rtinfo; struct Route *p, *temp;

while (adj_rtinfo != NULL) {
    p = rtinfo;
    while (p != NULL) {
        if (p->rt_net == adj_rtinfo->rt_net) {
            if (p->rt_nexthop == adj_rtinfo->rt_nexthop) {
                p->rt_distance = adj_rtinfo->rt_distance + 1;
                break;
            }
            if (p->rt_distance > adj_rtinfo->rt_distance + 1) {
                p->rt_distance = adj_rtinfo->rt_distance + 1;
                p->rt_nexthop = adj_rtinfo->rt_nexthop;
                break;
            }
            break;
        }
        p = p->rt_next;
    }
    if (p == NULL) {
        temp = (struct Route*)malloc(sizeof(struct Route));
        temp->rt_ifnum = -1;
        temp->rt_net = adj_rtinfo->rt_net;
        temp->rt_mask = adj_rtinfo->rt_mask;
        temp->rt_nexthop = adj_rtinfo->rt_nexthop;
        temp->rt_distance = adj_rtinfo->rt_distance + 1;
        uint32 maxnif = 0;
        uint32 maxnet = 0;
        for (int i = 1; netif[i].ni_device > 0; i++) {
            if ((temp->rt_nexthop & netif[i].ni_mask) == (netif[i].ni_ip & netif[i].ni_mask)) {
                if ((temp->rt_nexthop & netif[i].ni_mask) >= maxnet) {
                    maxnet = temp->rt_nexthop & netif[i].ni_mask;
                    maxnif = i;
                }
            }
        }
        if (maxnif > 0) {
            temp->rt_ifnum = maxnif;
        }
        temp->rt_next = rtinfo;
        rtinfo = temp;
    }
    adj_rtinfo = adj_rtinfo->rt_next;
}
return res;