From 4582497e8839d7a3d73aa71f76c2aae915202d41 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Sat, 24 Dec 2016 14:06:12 -0600 Subject: Cleanup: Have get_hostname() handle its own lookup failures. Inline is_prefix(). Kernel can handle 64k maximum segment size. --- toys/pending/route.c | 85 +++++++++++++++++++++++++++++----------------------- 1 file changed, 48 insertions(+), 37 deletions(-) diff --git a/toys/pending/route.c b/toys/pending/route.c index dd7dfc3b..3a00687d 100644 --- a/toys/pending/route.c +++ b/toys/pending/route.c @@ -5,20 +5,45 @@ * * No Standard * + * TODO: autodetect -net -host target dev -A (but complain) + * route add -net target 10.0.0.0 netmask 255.0.0.0 dev eth0 + * route del delete + * delete net route, must match netmask, informative error message + * + * mod dyn reinstate metric netmask gw mss window irtt dev + USE_ROUTE(NEWTOY(route, "?neA:", TOYFLAG_BIN)) config ROUTE bool "route" default n help - usage: route [-ne] [-A inet[6]] / [add|del] + usage: route [-ne] [-A [46]] [add|del TARGET [OPTIONS]] + + Display, add or delete network routes in the "Forwarding Information Base". + + -n Show numerical addresses (no DNS lookups) + -e display netstat fields + + Routing means sending packets out a network interface to an address. + The kernel can tell where to send packets one hop away by examining each + interface's address and netmask, so the most common use of this command + is to identify a "gateway" that forwards other traffic. - Display/Edit kernel routing tables. + Assigning an address to an interface automatically creates an appropriate + network route ("ifconfig eth0 10.0.2.15/8" does "route add 10.0.0.0/8 eth0" + for you), although some devices (such as loopback) won't show it in the + table. For machines more than one hop away, you need to specify a gateway + (ala "route add default gw 10.0.2.2"). - -n no name lookups - -e display other/more information - -A inet{6} Select Address Family + The address "default" is a wildcard address (0.0.0.0/0) matching all + packets without a more specific route. + + Available OPTIONS include: + reject - blocking route (force match failure) + dev NAME - force packets out this interface (ala "eth0") + netmask - old way of saying things like ADDR/24 + gw ADDR - forward packets to gateway ADDR - reject mod dyn reinstate metric netmask gw mss window irtt dev */ #define FOR_route @@ -63,8 +88,9 @@ static int get_hostname(char *ipstr, struct sockaddr_in *sockin) } if (inet_aton(ipstr, &sockin->sin_addr)) return 0; - if (!(host = gethostbyname(ipstr))) return -1; + if (!(host = gethostbyname(ipstr))) perror_exit("resolving '%s'", ipstr); memcpy(&sockin->sin_addr, host->h_addr_list[0], sizeof(struct in_addr)); + return 0; } @@ -159,24 +185,6 @@ static int get_action(char ***argv, struct _arglist *list) 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. @@ -201,22 +209,18 @@ static void get_next_params(char **argv, struct rtentry *rt, char **netmask) if (addr_mask) help_exit("dup netmask"); *netmask = *argv; - if (get_hostname(*netmask, (struct sockaddr_in *) &sock) < 0) - perror_exit("resolving '%s'", *netmask); + get_hostname(*netmask, (struct sockaddr_in *) &sock); 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) { + if (!get_hostname(*argv, (struct sockaddr_in *) &rt->rt_gateway)) 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_mtu = atolx_range(*argv, 64, 65536); rt->rt_flags |= RTF_MSS; } else if (!strcmp(*argv, "window")) { //set the TCP window size for connections over this route to W bytes. @@ -253,7 +257,7 @@ static void verify_netmask(struct rtentry *rt, char *netmask) static void setroute(char **argv) { struct rtentry rt; - char *netmask = NULL, *targetip; + char *netmask, *targetip; int is_net_or_host = 0, sokfd, arg2_action; int action = get_action(&argv, arglist1); //verify the arg for add/del. @@ -265,10 +269,17 @@ static void setroute(char **argv) 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); + netmask = strchr(targetip, '/'); + if (netmask) { + *netmask++ = 0; + //used to verify the netmask and route conflict. + (((struct sockaddr_in *)&rt.rt_genmask)->sin_addr.s_addr) + = htonl((1<<(32-atolx_range(netmask, 0, 32)))-1); + rt.rt_genmask.sa_family = AF_INET; + netmask = 0; + } else netmask = "default"; + + is_net_or_host = get_hostname(targetip, (void *)&rt.rt_dst); if (arg2_action) is_net_or_host = arg2_action & 1; rt.rt_flags = ((is_net_or_host) ? RTF_UP : (RTF_UP | RTF_HOST)); -- cgit v1.2.3