Путь: Toys/Pending, команды версии: Ver.4 Ver.9 route Комментарии в файле route.c :
Исходный текст в файле route.c #define FOR_route
#include "toys.h"
#define _LINUX_SYSINFO_H // workaround for musl bug
#include <linux/rtnetlink.h>
GLOBALS(
char *A;
)
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 }
};
void xsend(int sockfd, void *buf, size_t len)
{
if (send(sockfd, buf, len, 0) != len) perror_exit("xsend");
}
int xrecv(int sockfd, void *buf, size_t len)
{
int msg_len = recv(sockfd, buf, len, 0);
if (msg_len < 0) perror_exit("xrecv");
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;
}
static void get_hostname(sa_family_t f, void *a, char *dst, size_t len) {
size_t a_len = (AF_INET6 == f) ? sizeof(struct in6_addr) : sizeof(struct in_addr);
struct hostent *host = gethostbyaddr(a, a_len, f);
if (host) xstrncpy(dst, host->h_name, len);
}
static void display_routes(sa_family_t f)
{
int fd, msg_hdr_len, route_protocol;
struct {
struct nlmsghdr nl;
struct rtmsg rt;
} req;
struct nlmsghdr buf[8192 / sizeof(struct nlmsghdr)];
struct nlmsghdr *msg_hdr_ptr;
struct rtmsg *route_entry;
struct rtattr *rteattr;
fd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
memset(&req, 0, sizeof(req));
req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
req.nl.nlmsg_type = RTM_GETROUTE;
req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
req.nl.nlmsg_pid = getpid();
req.nl.nlmsg_seq = 1;
req.rt.rtm_family = f;
req.rt.rtm_table = RT_TABLE_MAIN;
xsend(fd, &req, sizeof(req));
if (f == AF_INET) {
xprintf("Kernel IP routing table\n"
"Destination Gateway Genmask Flags %s Iface\n",
FLAG(e) ? " MSS Window irtt" : "Metric Ref Use");
} else {
xprintf("Kernel IPv6 routing table\n"
"%-31s%-26s Flag Metric Ref Use If\n", "Destination", "Next Hop");
}
msg_hdr_len = xrecv(fd, buf, sizeof(buf));
msg_hdr_ptr = buf;
while (msg_hdr_ptr->nlmsg_type != NLMSG_DONE) {
while (NLMSG_OK(msg_hdr_ptr, msg_hdr_len)) {
route_entry = NLMSG_DATA(msg_hdr_ptr);
route_protocol = route_entry->rtm_protocol;
// Annoyingly NLM_F_MATCH is not yet implemented so even if we pass in
// RT_TABLE_MAIN with RTM_GETROUTE it still returns everything so we
// have to filter here.
if (route_entry->rtm_table == RT_TABLE_MAIN) {
int route_attribute_len;
char dest[INET6_ADDRSTRLEN], gate[INET6_ADDRSTRLEN], netmask[32],
flags[10] = "U", if_name[IF_NAMESIZE] = "-";
unsigned priority = 0, mss = 0, win = 0, irtt = 0, ref = 0, use = 0,
route_netmask, metric_len;
struct in_addr netmask_addr;
struct rtattr *metric;
struct rta_cacheinfo *cache_info;
if (f == AF_INET) {
strcpy(dest, FLAG(n) ? "0.0.0.0" : "default");
strcpy(gate, FLAG(n) ? "*" : "0.0.0.0");
strcpy(netmask, "0.0.0.0");
} else {
strcpy(dest, "::");
strcpy(gate, "::");
}
route_netmask = route_entry->rtm_dst_len;
if (route_netmask == 0) netmask_addr.s_addr = ~((in_addr_t) -1);
else netmask_addr.s_addr = htonl(~((1 << (32 - route_netmask)) - 1));
inet_ntop(AF_INET, &netmask_addr, netmask, sizeof(netmask));
rteattr = RTM_RTA(route_entry);
route_attribute_len = RTM_PAYLOAD(msg_hdr_ptr);
while (RTA_OK(rteattr, route_attribute_len)) {
switch (rteattr->rta_type) {
case RTA_DST:
if (FLAG(n)) inet_ntop(f, RTA_DATA(rteattr), dest, sizeof(dest));
else get_hostname(f, RTA_DATA(rteattr), dest, sizeof(dest));
break;
case RTA_GATEWAY:
if (FLAG(n)) inet_ntop(f, RTA_DATA(rteattr), gate, sizeof(dest));
else get_hostname(f, RTA_DATA(rteattr), gate, sizeof(dest));
strcat(flags, "G");
break;
case RTA_PRIORITY:
priority = *(unsigned *)RTA_DATA(rteattr);
break;
case RTA_OIF:
if_indextoname(*(int *)RTA_DATA(rteattr), if_name);
break;
case RTA_METRICS:
metric_len = RTA_PAYLOAD(rteattr);
for (metric = RTA_DATA(rteattr); RTA_OK(metric, metric_len);
metric = RTA_NEXT(metric, metric_len))
if (metric->rta_type == RTAX_ADVMSS)
mss = *(unsigned *)RTA_DATA(metric);
else if (metric->rta_type == RTAX_WINDOW)
win = *(unsigned *)RTA_DATA(metric);
else if (metric->rta_type == RTAX_RTT)
irtt = (*(unsigned *)RTA_DATA(metric))/8;
break;
case RTA_CACHEINFO:
cache_info = RTA_DATA(rteattr);
ref = cache_info->rta_clntref;
use = cache_info->rta_used;
break;
}
rteattr = RTA_NEXT(rteattr, route_attribute_len);
}
if (route_entry->rtm_type == RTN_UNREACHABLE) flags[0] = '!';
if (route_netmask == 32) strcat(flags, "H");
if (route_protocol == RTPROT_REDIRECT) strcat(flags, "D");
if (f == AF_INET) {
xprintf("%-15.15s %-15.15s %-16s%-6s", dest, gate, netmask, flags);
if (FLAG(e)) xprintf("%5d %-5d %6d %s\n", mss, win, irtt, if_name);
else xprintf("%-6d %-2d %7d %s\n", priority, ref, use, if_name);
} else {
char *dest_with_mask = xmprintf("%s/%u", dest, route_netmask);
xprintf("%-30s %-26s %-4s %-6d %-4d %2d %-8s\n",
dest_with_mask, gate, flags, priority, ref, use, if_name);
free(dest_with_mask);
}
}
msg_hdr_ptr = NLMSG_NEXT(msg_hdr_ptr, msg_hdr_len);
}
msg_hdr_len = xrecv(fd, buf, sizeof(buf));
msg_hdr_ptr = buf;
}
xclose(fd);
}
// find parameter (add/del/net/host) in list, return appropriate action or 0.
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;
}
// add/del a route.
static void setroute(sa_family_t f, char **argv)
{
char *tgtip;
int sockfd, arg2_action;
int action = get_action(&argv, arglist1); //verify the arg for add/del.
struct nlmsghdr buf[8192 / sizeof(struct nlmsghdr)];
struct nlmsghdr *nlMsg;
struct rtmsg *rtMsg;
if (!action || !*argv) help_exit("setroute");
arg2_action = get_action(&argv, arglist2); //verify the arg for -net or -host
if (!*argv) help_exit("setroute");
tgtip = *argv++;
sockfd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
memset(buf, 0, sizeof(buf));
nlMsg = (struct nlmsghdr *) buf;
rtMsg = (struct rtmsg *) NLMSG_DATA(nlMsg);
nlMsg->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
//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;
}
nlMsg->nlmsg_pid = getpid();
nlMsg->nlmsg_seq = 1;
rtMsg->rtm_family = f;
rtMsg->rtm_table = RT_TABLE_UNSPEC;
rtMsg->rtm_type = RTN_UNICAST;
rtMsg->rtm_protocol = RTPROT_UNSPEC;
rtMsg->rtm_flags = RTM_F_NOTIFY;
rtMsg->rtm_dst_len = rtMsg->rtm_src_len = (f == AF_INET) ? 32 : 128;
if (arg2_action == 2) rtMsg->rtm_scope = RT_SCOPE_HOST;
size_t addr_len = sizeof(struct in_addr);
if (f == 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]) show_help(stdout, 1);
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 = (f == 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(f, argv[1], &naddr)) error_exit("invalid netmask");
if (f == 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(f, 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(tgtip, "default") != 0) {
char *prefix = strtok(0, "/");
if (prefix) rtMsg->rtm_dst_len = strtoul(prefix, &prefix, 0);
if (!inet_pton(f, strtok(tgtip, "/"), &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);
}
void route_main(void)
{
if (!*toys.optargs) {
if (!TT.A || !strcmp(TT.A, "inet")) display_routes(AF_INET);
else if (!strcmp(TT.A, "inet6")) display_routes(AF_INET6);
else show_help(stdout, 1);
} else {
if (!TT.A) {
if (toys.optc>1 && strchr(toys.optargs[1], ':')) {
xprintf("WARNING: Implicit IPV6 address using -Ainet6\n");
TT.A = "inet6";
} else TT.A = "inet";
}
if (!strcmp(TT.A, "inet")) setroute(AF_INET, toys.optargs);
else setroute(AF_INET6, toys.optargs);
}
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