/* route.c - Display/edit network routing table. * * Copyright 2012 Ranjan Kumar <ranjankumar.bth@gmail.com> * Copyright 2013 Kyungwan Han <asura321@gmail.com> * * No Standard * USE_ROUTE(NEWTOY(route, "?neA:", TOYFLAG_BIN)) config ROUTE bool "route" default n help usage: route [-ne] [-A inet[6]] / [add|del] Display/Edit kernel routing tables. -n no name lookups -e display other/more information -A inet{6} Select Address Family reject mod dyn reinstate metric netmask gw mss window irtt dev */ #define FOR_route #include "toys.h" #include <net/route.h> GLOBALS( char *family; ) #define DEFAULT_PREFIXLEN 128 #define INVALID_ADDR 0xffffffffUL #define IPV6_ADDR_LEN 40 //32 + 7 (':') + 1 ('\0') struct _arglist { char *arg; int action; }; static struct _arglist arglist1[] = { { "add", 1 }, { "del", 2 }, { "delete", 2 }, { NULL, 0 } }; static struct _arglist arglist2[] = { { "-net", 1 }, { "-host", 2 }, { NULL, 0 } }; // to get the host name from the given ip. static int get_hostname(char *ipstr, struct sockaddr_in *sockin) { struct hostent *host; sockin->sin_family = AF_INET; sockin->sin_port = 0; if (!strcmp(ipstr, "default")) { sockin->sin_addr.s_addr = INADDR_ANY; return 1; } if (inet_aton(ipstr, &sockin->sin_addr)) return 0; if (!(host = gethostbyname(ipstr))) return -1; memcpy(&sockin->sin_addr, host->h_addr_list[0], sizeof(struct in_addr)); return 0; } // used to extract the address info from the given ip. static int get_addrinfo(char *ip, struct sockaddr_in6 *sock_in6) { struct addrinfo hints, *result; int status = 0; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = AF_INET6; if ((status = getaddrinfo(ip, NULL, &hints, &result))) { perror_msg("getaddrinfo: %s", gai_strerror(status)); return -1; } if (result) { memcpy(sock_in6, result->ai_addr, sizeof(*sock_in6)); freeaddrinfo(result); } return 0; } static void get_flag_value(char *str, int flags) { // RTF_* bits in order: // UP, GATEWAY, HOST, REINSTATE, DYNAMIC, MODIFIED, DEFAULT, ADDRCONF, CACHE int i = 0, mask = 0x105003f; for (; mask; mask>>=1) if (mask&1) { if (flags&(1<<i)) *str++ = "UGHRDMDAC"[i]; i++; } *str = 0; } // extract inet4 route info from /proc/net/route file and display it. static void display_routes(void) { unsigned long dest, gate, mask; int flags, ref, use, metric, mss, win, irtt, items; char iface[64] = {0,}, flag_val[10]; //there are 9 flags "UGHRDMDAC" for route. FILE *fp = xfopen("/proc/net/route", "r"); xprintf("Kernel IP routing table\n" "Destination Gateway Genmask Flags %s Iface\n", (toys.optflags & FLAG_e)? " MSS Window irtt" : "Metric Ref Use"); if (fscanf(fp, "%*[^\n]\n") < 0) perror_exit("fscanf"); //skip 1st line while ((items = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n", iface, &dest, &gate, &flags, &ref, &use, &metric, &mask, &mss, &win, &irtt)) == 11) { char *destip = toybuf, *gateip = toybuf+32, *maskip = toybuf+64; //ip string 16 if (!(flags & RTF_UP)) continue; //skip down interfaces. if (!dest && !(toys.optflags & FLAG_n)) strcpy( destip, "default"); else if (!inet_ntop(AF_INET, &dest, destip, 32)) perror_exit("inet"); if (!gate && !(toys.optflags & FLAG_n)) strcpy( gateip, "*"); else if (!inet_ntop(AF_INET, &gate, gateip, 32)) perror_exit("inet"); if (!inet_ntop(AF_INET, &mask, maskip, 32)) perror_exit("inet"); //Get flag Values get_flag_value(flag_val, flags); if (flags & RTF_REJECT) flag_val[0] = '!'; xprintf("%-15.15s %-15.15s %-16s%-6s", destip, gateip, maskip, flag_val); if (toys.optflags & FLAG_e) xprintf("%5d %-5d %6d %s\n", mss, win, irtt, iface); else xprintf("%-6d %-2d %7d %s\n", metric, ref, use, iface); } if (items > 0 && feof(fp)) perror_exit("fscanf %d", items); fclose(fp); } /* * find the given parameter in list like add/del/net/host. * and if match found return the appropriate action. */ static int get_action(char ***argv, struct _arglist *list) { struct _arglist *alist; if (!**argv) return 0; for (alist = list; alist->arg; alist++) { //find the given parameter in list if (!strcmp(**argv, alist->arg)) { *argv += 1; return alist->action; } } return 0; } /* * get prefix len (if any) and remove the prefix from target ip. * if no prefix then set netmask as default. */ static void is_prefix(char **tip, char **netmask, struct rtentry *rt) { char *prefix = strchr(*tip, '/'); if (prefix) { unsigned long plen; plen = atolx_range(prefix + 1, 0, 32); //used to verify the netmask and route conflict. (((struct sockaddr_in *)&((rt)->rt_genmask))->sin_addr.s_addr) = htonl( ~(INVALID_ADDR >> plen)); *prefix = '\0'; rt->rt_genmask.sa_family = AF_INET; } else *netmask = "default"; //default netmask. } /* * used to get the params like: metric, netmask, gw, mss, window, irtt, dev and their values. * additionally set the flag values for reject, mod, dyn and reinstate. */ static void get_next_params(char **argv, struct rtentry *rt, char **netmask) { for (;*argv;argv++) { if (!strcmp(*argv, "reject")) rt->rt_flags |= RTF_REJECT; else if (!strcmp(*argv, "mod")) rt->rt_flags |= RTF_MODIFIED; else if (!strcmp(*argv, "dyn")) rt->rt_flags |= RTF_DYNAMIC; else if (!strcmp(*argv, "reinstate")) rt->rt_flags |= RTF_REINSTATE; else { if (!argv[1]) help_exit(0); //set the metric field in the routing table. if (!strcmp(*argv, "metric")) rt->rt_metric = atolx_range(*argv, 0, ULONG_MAX) + 1; else if (!strcmp(*argv, "netmask")) { //when adding a network route, the netmask to be used. struct sockaddr sock; unsigned int addr_mask = (((struct sockaddr_in *)&((rt)->rt_genmask))->sin_addr.s_addr); if (addr_mask) help_exit("dup netmask"); *netmask = *argv; if (get_hostname(*netmask, (struct sockaddr_in *) &sock) < 0) perror_exit("resolving '%s'", *netmask); rt->rt_genmask = sock; } else if (!strcmp(*argv, "gw")) { //route packets via a gateway. if (!(rt->rt_flags & RTF_GATEWAY)) { int ishost; if ((ishost = get_hostname(*argv, (struct sockaddr_in *) &rt->rt_gateway)) == 0) { rt->rt_flags |= RTF_GATEWAY; } else if (ishost < 0) perror_exit("resolving '%s'", *argv); else perror_exit("gateway '%s' is a NETWORK", *argv); } else help_exit("dup gw"); } else if (!strcmp(*argv, "mss")) { //set the TCP Maximum Segment Size for connections over this route. rt->rt_mss = atolx_range(*argv, 64, 32768); //MSS low and max rt->rt_flags |= RTF_MSS; } else if (!strcmp(*argv, "window")) { //set the TCP window size for connections over this route to W bytes. rt->rt_window = atolx_range(*argv, 128, INT_MAX); //win low rt->rt_flags |= RTF_WINDOW; } else if (!strcmp(*argv, "irtt")) { rt->rt_irtt = atolx_range(*argv, 0, INT_MAX); rt->rt_flags |= RTF_IRTT; } else if (!strcmp(*argv, "dev") && !rt->rt_dev) rt->rt_dev = *argv; else help_exit("no '%s'", *argv); } } if (!rt->rt_dev && (rt->rt_flags & RTF_REJECT)) rt->rt_dev = (char *)"lo"; } // verify the netmask and conflict in netmask and route address. static void verify_netmask(struct rtentry *rt, char *netmask) { unsigned int addr_mask = (((struct sockaddr_in *)&((rt)->rt_genmask))->sin_addr.s_addr); unsigned int router_addr = ~(unsigned int)(((struct sockaddr_in *)&((rt)->rt_dst))->sin_addr.s_addr); if (addr_mask) { addr_mask = ~ntohl(addr_mask); if ((rt->rt_flags & RTF_HOST) && addr_mask != INVALID_ADDR) perror_exit("conflicting netmask and host route"); if (addr_mask & (addr_mask + 1)) perror_exit("wrong netmask '%s'", netmask); addr_mask = ((struct sockaddr_in *) &rt->rt_dst)->sin_addr.s_addr; if (addr_mask & router_addr) perror_exit("conflicting netmask and route address"); } } // add/del a route. static void setroute(char **argv) { struct rtentry rt; char *netmask = NULL, *targetip; int is_net_or_host = 0, sokfd, arg2_action; int action = get_action(&argv, arglist1); //verify the arg for add/del. if (!action || !*argv) help_exit("setroute"); arg2_action = get_action(&argv, arglist2); //verify the arg for -net or -host if (!*argv) help_exit("setroute"); memset(&rt, 0, sizeof(struct rtentry)); targetip = *argv++; is_prefix((char **)&targetip, (char **)&netmask, &rt); if ((is_net_or_host = get_hostname(targetip, (struct sockaddr_in *) &rt.rt_dst)) < 0) perror_exit("resolving '%s'", targetip); if (arg2_action) is_net_or_host = arg2_action & 1; rt.rt_flags = ((is_net_or_host) ? RTF_UP : (RTF_UP | RTF_HOST)); get_next_params(argv, &rt, (char **)&netmask); verify_netmask(&rt, (char *)netmask); if ((action == 1) && (rt.rt_flags & RTF_HOST)) (((struct sockaddr_in *)&((rt).rt_genmask))->sin_addr.s_addr) = INVALID_ADDR; sokfd = xsocket(AF_INET, SOCK_DGRAM, 0); if (action == 1) xioctl(sokfd, SIOCADDRT, &rt); else xioctl(sokfd, SIOCDELRT, &rt); xclose(sokfd); } /* * get prefix len (if any) and remove the prefix from target ip. * if no prefix then set default prefix len. */ static void is_prefix_inet6(char **tip, struct in6_rtmsg *rt) { unsigned long plen; char *prefix = strchr(*tip, '/'); if (prefix) { *prefix = '\0'; plen = atolx_range(prefix + 1, 0, 128); //DEFAULT_PREFIXLEN); } else plen = DEFAULT_PREFIXLEN; rt->rtmsg_flags = (plen == DEFAULT_PREFIXLEN) ? (RTF_UP | RTF_HOST) : RTF_UP; rt->rtmsg_dst_len = plen; } /* * used to get the params like: metric, gw, dev and their values. * additionally set the flag values for mod and dyn. */ static void get_next_params_inet6(char **argv, struct sockaddr_in6 *sock_in6, struct in6_rtmsg *rt, char **dev_name) { for (;*argv;argv++) { if (!strcmp(*argv, "mod")) rt->rtmsg_flags |= RTF_MODIFIED; else if (!strcmp(*argv, "dyn")) rt->rtmsg_flags |= RTF_DYNAMIC; else { if (!argv[1]) help_exit(0); if (!strcmp(*argv, "metric")) rt->rtmsg_metric = atolx_range(*argv, 0, ULONG_MAX); else if (!strcmp(*argv, "gw")) { //route packets via a gateway. if (!(rt->rtmsg_flags & RTF_GATEWAY)) { if (!get_addrinfo(*argv, (struct sockaddr_in6 *) &sock_in6)) { memcpy(&rt->rtmsg_gateway, sock_in6->sin6_addr.s6_addr, sizeof(struct in6_addr)); rt->rtmsg_flags |= RTF_GATEWAY; } else perror_exit("resolving '%s'", *argv); } else help_exit(0); } else if (!strcmp(*argv, "dev")) { if (!*dev_name) *dev_name = *argv; } else help_exit(0); } } } // add/del a route. static void setroute_inet6(char **argv) { struct sockaddr_in6 sock_in6; struct in6_rtmsg rt; char *targetip, *dev_name = 0; int sockfd, action = get_action(&argv, arglist1); if (!action || !*argv) help_exit(0); memset(&sock_in6, 0, sizeof(struct sockaddr_in6)); memset(&rt, 0, sizeof(struct in6_rtmsg)); targetip = *argv++; if (!*argv) help_exit(0); if (!strcmp(targetip, "default")) { rt.rtmsg_flags = RTF_UP; rt.rtmsg_dst_len = 0; } else { is_prefix_inet6((char **)&targetip, &rt); if (get_addrinfo(targetip, (struct sockaddr_in6 *) &sock_in6)) perror_exit("resolving '%s'", targetip); } rt.rtmsg_metric = 1; //default metric. memcpy(&rt.rtmsg_dst, sock_in6.sin6_addr.s6_addr, sizeof(struct in6_addr)); get_next_params_inet6(argv, &sock_in6, &rt, (char **)&dev_name); sockfd = xsocket(AF_INET6, SOCK_DGRAM, 0); if (dev_name) { char ifre_buf[sizeof(struct ifreq)] = {0,}; struct ifreq *ifre = (struct ifreq*)ifre_buf; xstrncpy(ifre->ifr_name, dev_name, IFNAMSIZ); xioctl(sockfd, SIOGIFINDEX, ifre); rt.rtmsg_ifindex = ifre->ifr_ifindex; } if (action == 1) xioctl(sockfd, SIOCADDRT, &rt); else xioctl(sockfd, SIOCDELRT, &rt); xclose(sockfd); } /* * format the dest and src address in ipv6 format. * e.g. 2002:6b6d:26c8:d:ea03:9aff:fe65:9d62 */ static void ipv6_addr_formating(char *ptr, char *addr) { int i = 0; while (i <= IPV6_ADDR_LEN) { if (!*ptr) { if (i == IPV6_ADDR_LEN) { addr[IPV6_ADDR_LEN - 1] = 0; //NULL terminating the ':' seperated address. break; } error_exit("IPv6 ip format error"); } addr[i++] = *ptr++; if (!((i+1) % 5)) addr[i++] = ':'; //put ':' after 4th bit } } static void display_routes6(void) { char iface[16] = {0,}, ipv6_dest_addr[41]; char ipv6_src_addr[41], flag_val[10], buf2[INET6_ADDRSTRLEN]; int prefixlen, metric, use, refcount, flag, items = 0; unsigned char buf[sizeof(struct in6_addr)]; FILE *fp = xfopen("/proc/net/ipv6_route", "r"); xprintf("Kernel IPv6 routing table\n" "%-43s%-40s Flags Metric Ref Use Iface\n", "Destination", "Next Hop"); while ((items = fscanf(fp, "%32s%x%*s%*x%32s%x%x%x%x%10s\n", ipv6_dest_addr+8, &prefixlen, ipv6_src_addr+8, &metric, &use, &refcount, &flag, iface)) == 8) { if (!(flag & RTF_UP)) continue; //skip down interfaces. //ipv6_dest_addr+8: as the values are filled from the 8th location of the array. ipv6_addr_formating(ipv6_dest_addr+8, ipv6_dest_addr); ipv6_addr_formating(ipv6_src_addr+8, ipv6_src_addr); get_flag_value(flag_val, flag); if (inet_pton(AF_INET6, ipv6_dest_addr, buf) <= 0) perror_exit("inet"); if (inet_ntop(AF_INET6, buf, buf2, INET6_ADDRSTRLEN)) sprintf(toybuf, "%s/%d", buf2, prefixlen); if (inet_pton(AF_INET6, ipv6_src_addr, buf) <= 0) perror_exit("inet"); if (inet_ntop(AF_INET6, buf, buf2, INET6_ADDRSTRLEN)) xprintf("%-43s %-39s %-5s %-6d %-4d %5d %-8s\n", toybuf, buf2, flag_val, metric, refcount, use, iface); } if ((items > 0) && feof(fp)) perror_exit("fscanf"); fclose(fp); } void route_main(void) { if (!TT.family) TT.family = "inet"; if (!*toys.optargs) { if (!strcmp(TT.family, "inet")) display_routes(); else if (!strcmp(TT.family, "inet6")) display_routes6(); else help_exit(0); } else { if (!strcmp(TT.family, "inet6")) setroute_inet6(toys.optargs); else setroute(toys.optargs); } }