[Toybox] [PATCH 3/3] First pass of adding RTNetlink setroute support
Eric Molitor
emolitor at molitor.org
Mon May 25 06:25:48 PDT 2020
---
toys/pending/route.c | 221 +++++++++++++++++++++++++------------------
1 file changed, 127 insertions(+), 94 deletions(-)
diff --git a/toys/pending/route.c b/toys/pending/route.c
index cc6ecd54..a24e146e 100644
--- a/toys/pending/route.c
+++ b/toys/pending/route.c
@@ -88,6 +88,18 @@ int xrecv(int sockfd, void *buf, size_t len)
return msg_len;
}
+void addAttr(struct nlmsghdr *nl, int maxlen, void *attr, int type, int len)
+{
+ struct rtattr *rt;
+ int rtlen = RTA_LENGTH(len);
+ if (NLMSG_ALIGN(nl->nlmsg_len) + rtlen > maxlen) perror_exit("addAttr");
+ rt = (struct rtattr*)((char *)nl + NLMSG_ALIGN(nl->nlmsg_len));
+ rt->rta_type = type;
+ rt->rta_len = rtlen;
+ memcpy(RTA_DATA(rt), attr, len);
+ nl->nlmsg_len = NLMSG_ALIGN(nl->nlmsg_len) + rtlen;
+}
+
// to get the host name from the given ip.
static int get_hostname(char *ipstr, struct sockaddr_in *sockin)
{
@@ -297,81 +309,11 @@ static int get_action(char ***argv, struct _arglist *list)
return 0;
}
-/*
- * 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[1], 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[1];
- 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)) {
- if (!get_hostname(argv[1], (struct sockaddr_in *) &rt->rt_gateway))
- rt->rt_flags |= RTF_GATEWAY;
- else perror_exit("gateway '%s' is a NETWORK", argv[1]);
- } else help_exit("dup gw");
- } else if (!strcmp(*argv, "mss")) {
- //set the TCP Maximum Segment Size for connections over this route.
- rt->rt_mtu = atolx_range(argv[1], 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.
- rt->rt_window = atolx_range(argv[1], 128, INT_MAX); //win low
- rt->rt_flags |= RTF_WINDOW;
- } else if (!strcmp(*argv, "irtt")) {
- rt->rt_irtt = atolx_range(argv[1], 0, INT_MAX);
- rt->rt_flags |= RTF_IRTT;
- } else if (!strcmp(*argv, "dev") && !rt->rt_dev) rt->rt_dev = argv[1];
- else help_exit("no '%s'", *argv);
- 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)
+static void setroute(sa_family_t family, char **argv)
{
- struct rtentry rt;
- char *netmask, *targetip;
- int is_net_or_host, sockfd, arg2_action;
+ char *targetip;
+ int sockfd, arg2_action;
int action = get_action(&argv, arglist1); //verify the arg for add/del.
if (!action || !*argv) help_exit("setroute");
@@ -379,33 +321,124 @@ static void setroute(char **argv)
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++;
- 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";
+ struct nlmsghdr *nlMsg;
+ struct rtmsg *rtMsg;
- is_net_or_host = get_hostname(targetip, (void *)&rt.rt_dst);
+ sockfd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ memset(toybuf, 0, sizeof(toybuf));
+ nlMsg = (struct nlmsghdr *) toybuf;
+ rtMsg = (struct rtmsg *) NLMSG_DATA(nlMsg);
- if (arg2_action) is_net_or_host = arg2_action & 1;
- rt.rt_flags = ((is_net_or_host) ? RTF_UP : (RTF_UP | RTF_HOST));
+ nlMsg->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
- get_next_params(argv, &rt, (char **)&netmask);
- verify_netmask(&rt, (char *)netmask);
+ //TODO(emolitor): Improve action and arg2_action handling
+ if (action == 1) { // Add
+ nlMsg->nlmsg_type = RTM_NEWROUTE;
+ nlMsg->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
+ } else { // Delete
+ nlMsg->nlmsg_type = RTM_DELROUTE;
+ nlMsg->nlmsg_flags = NLM_F_REQUEST;
+ }
- if ((action == 1) && (rt.rt_flags & RTF_HOST))
- (((struct sockaddr_in *)&((rt).rt_genmask))->sin_addr.s_addr) = INVALID_ADDR;
+ nlMsg->nlmsg_pid = getpid();
+ nlMsg->nlmsg_seq = 1;
+ rtMsg->rtm_family = family;
+ rtMsg->rtm_table = RT_TABLE_UNSPEC;
+ rtMsg->rtm_type = RTN_UNICAST;
+ rtMsg->rtm_protocol = RTPROT_UNSPEC;
+ rtMsg->rtm_flags = RTM_F_NOTIFY;
+ if (family == AF_INET) {
+ rtMsg->rtm_dst_len = 32;
+ rtMsg->rtm_src_len = 32;
+ } else {
+ rtMsg->rtm_dst_len = 128;
+ rtMsg->rtm_src_len = 128;
+ }
- sockfd = xsocket(AF_INET, SOCK_DGRAM, 0);
- if (action == 1) xioctl(sockfd, SIOCADDRT, &rt);
- else xioctl(sockfd, SIOCDELRT, &rt);
+ if (arg2_action == 2) {
+ rtMsg->rtm_scope = RT_SCOPE_HOST;
+ }
+
+ size_t addr_len = sizeof(struct in_addr);
+ if (family == AF_INET6) addr_len = sizeof(struct in6_addr);
+ unsigned char addr[sizeof(struct in6_addr)] = {0,};
+
+ for (; *argv; argv++) {
+ if (!strcmp(*argv, "mod")) {
+ continue;
+ } else if (!strcmp(*argv, "dyn")) {
+ continue;
+ } else if (!strcmp(*argv, "reinstate")) {
+ continue;
+ } else if (!strcmp(*argv, "reject")) {
+ rtMsg->rtm_type = RTN_UNREACHABLE;
+ } else {
+ if (!argv[1]) help_exit(0);
+
+ if (!strcmp(*argv, "metric")) {
+ unsigned int priority = atolx_range(argv[1], 0, UINT_MAX);
+ addAttr(nlMsg, sizeof(toybuf), &priority, RTA_PRIORITY, sizeof(unsigned int));
+ } else if (!strcmp(*argv, "netmask")) {
+ uint32_t netmask;
+ char *ptr;
+ uint32_t naddr[4] = {0,};
+ uint64_t plen;
+
+ netmask = (family == AF_INET6) ? 128 : 32; // set default netmask
+ plen = strtoul(argv[1], &ptr, 0);
+
+ if (!ptr || ptr == argv[1] || *ptr || !plen || plen > netmask) {
+ if (!inet_pton(family, argv[1], &naddr)) error_exit("invalid netmask");
+ if (family == AF_INET) {
+ uint32_t mask = htonl(*naddr), host = ~mask;
+ if (host & (host + 1)) error_exit("invalid netmask");
+ for (plen = 0; mask; mask <<= 1) ++plen;
+ if (plen > 32) error_exit("invalid netmask");
+ }
+ }
+ netmask = plen;
+ rtMsg->rtm_dst_len = netmask;
+ } else if (!strcmp(*argv, "gw")) {
+ if (!inet_pton(family, argv[1], &addr)) error_exit("invalid gw");
+ addAttr(nlMsg, sizeof(toybuf), &addr, RTA_GATEWAY, addr_len);
+ } else if (!strcmp(*argv, "mss")) {
+ // TODO(emolitor): Add RTA_METRICS support
+ //set the TCP Maximum Segment Size for connections over this route.
+ //rt->rt_mtu = atolx_range(argv[1], 64, 65536);
+ //rt->rt_flags |= RTF_MSS;
+ } else if (!strcmp(*argv, "window")) {
+ // TODO(emolitor): Add RTA_METRICS support
+ //set the TCP window size for connections over this route to W bytes.
+ //rt->rt_window = atolx_range(argv[1], 128, INT_MAX); //win low
+ //rt->rt_flags |= RTF_WINDOW;
+ } else if (!strcmp(*argv, "irtt")) {
+ // TODO(emolitor): Add RTA_METRICS support
+ //rt->rt_irtt = atolx_range(argv[1], 0, INT_MAX);
+ //rt->rt_flags |= RTF_IRTT;
+ } else if (!strcmp(*argv, "dev")) {
+ unsigned int if_idx = if_nametoindex(argv[1]);
+ if (!if_idx) perror_exit("dev");
+ addAttr(nlMsg, sizeof(toybuf), &if_idx, RTA_OIF, sizeof(unsigned int));
+ } else help_exit("no '%s'", *argv);
+ argv++;
+ }
+ }
+
+ if (strcmp(targetip, "default") != 0) {
+ char *ptr;
+ char *dst = strtok(targetip, "/");
+ char *prefix = strtok(NULL, "/");
+
+ if (prefix) rtMsg->rtm_dst_len = strtoul(prefix, &ptr, 0);
+ if (!inet_pton(family, dst, &addr)) error_exit("invalid target");
+ addAttr(nlMsg, sizeof(toybuf), &addr, RTA_DST, addr_len);
+ } else {
+ rtMsg->rtm_dst_len = 0;
+ }
+
+ xsend(sockfd, nlMsg, nlMsg->nlmsg_len);
xclose(sockfd);
}
@@ -505,6 +538,6 @@ void route_main(void)
else help_exit(0);
} else {
if (!strcmp(TT.family, "inet6")) setroute_inet6(toys.optargs);
- else setroute(toys.optargs);
+ else setroute(AF_INET, toys.optargs);
}
}
--
2.25.1
More information about the Toybox
mailing list