From 27e0133d40f7b328482b501a18e22b12a55564ea Mon Sep 17 00:00:00 2001 From: Star Rauchenberger Date: Sun, 13 Jul 2025 10:07:59 -0400 Subject: Associate --- CMakeLists.txt | 4 +- src/addr_list.c | 17 ++++- src/addr_list.h | 4 +- src/main.c | 219 ++++++++++++++++++++++++------------------------------- src/retransmit.c | 169 ++++++++++++++++++++++++++++++++++++++++++ src/retransmit.h | 32 ++++++++ src/transmit.c | 55 ++++++++++++++ src/transmit.h | 6 ++ 8 files changed, 378 insertions(+), 128 deletions(-) create mode 100644 src/retransmit.c create mode 100644 src/retransmit.h create mode 100644 src/transmit.c create mode 100644 src/transmit.h diff --git a/CMakeLists.txt b/CMakeLists.txt index d784ebc..0ac3833 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -5,8 +5,10 @@ add_subdirectory(vendor/libwifi) set(SOURCE_FILES src/main.c - src/beacon_data.c src/addr_list.c + src/beacon_data.c + src/retransmit.c + src/transmit.c ) include_directories( diff --git a/src/addr_list.c b/src/addr_list.c index 759907e..e8ba571 100644 --- a/src/addr_list.c +++ b/src/addr_list.c @@ -9,7 +9,7 @@ void addr_list_init(struct addr_list* list) { list->top = NULL; } -void addr_list_add(struct addr_list* list, unsigned char addr[6]) { +void addr_list_add(struct addr_list* list, unsigned char addr[6], void* userdata) { struct addr_list_node* cur = list->top; struct addr_list_node* prev = NULL; @@ -25,6 +25,7 @@ void addr_list_add(struct addr_list* list, unsigned char addr[6]) { struct addr_list_node* next = (struct addr_list_node*)malloc(sizeof(struct addr_list_node)); next->next = NULL; memcpy(next->value, addr, 6); + next->userdata = userdata; if (prev == NULL) { list->top = next; @@ -47,6 +48,20 @@ bool addr_list_contains(struct addr_list* list, unsigned char addr[6]) { return false; } +void* addr_list_get(struct addr_list* list, unsigned char addr[6]) { + struct addr_list_node* cur = list->top; + + while (cur != NULL) { + if (!strncmp(cur->value, addr, 6)) { + return cur->userdata; + } + + cur = cur->next; + } + + return NULL; +} + void addr_list_remove(struct addr_list* list, unsigned char addr[6]) { struct addr_list_node* cur = list->top; struct addr_list_node* prev = NULL; diff --git a/src/addr_list.h b/src/addr_list.h index 66e217e..769d450 100644 --- a/src/addr_list.h +++ b/src/addr_list.h @@ -5,6 +5,7 @@ struct addr_list_node { unsigned char value[6]; + void* userdata; struct addr_list_node* next; }; @@ -13,8 +14,9 @@ struct addr_list { }; void addr_list_init(struct addr_list* list); -void addr_list_add(struct addr_list* list, unsigned char addr[6]); +void addr_list_add(struct addr_list* list, unsigned char addr[6], void* userdata); bool addr_list_contains(struct addr_list* list, unsigned char addr[6]); +void* addr_list_get(struct addr_list* list, unsigned char addr[6]); void addr_list_remove(struct addr_list* list, unsigned char addr[6]); void addr_list_free(struct addr_list* list); diff --git a/src/main.c b/src/main.c index b74907d..8eeb21f 100644 --- a/src/main.c +++ b/src/main.c @@ -14,10 +14,12 @@ #include "addr_list.h" #include "beacon_data.h" +#include "retransmit.h" +#include "transmit.h" -static unsigned char kBroadcastAddress[] = "\xFF\xFF\xFF\xFF\xFF\xFF"; +#define CHANNEL_NUM 13 -static pthread_mutex_t socket_mutex = PTHREAD_MUTEX_INITIALIZER; +static unsigned char kBroadcastAddress[] = "\xFF\xFF\xFF\xFF\xFF\xFF"; static pthread_mutex_t seq_mutex = PTHREAD_MUTEX_INITIALIZER; static int seq_number = 0; @@ -50,7 +52,8 @@ int get_interface_index(int sock, const char *interface, int *index) return 0; } -int get_next_seq_number() { +int get_next_seq_number() +{ pthread_mutex_lock(&seq_mutex); int next = seq_number++; pthread_mutex_unlock(&seq_mutex); @@ -62,7 +65,7 @@ int make_beacon_frame(int index, const unsigned char tx_addr[6], int seq_number, { struct libwifi_beacon beacon = {0}; - if (libwifi_create_beacon(&beacon, kBroadcastAddress, tx_addr, tx_addr, NULL, 13)) + if (libwifi_create_beacon(&beacon, kBroadcastAddress, tx_addr, tx_addr, NULL, CHANNEL_NUM)) { printf("Could not create beacon frame.\n"); return -3; @@ -80,7 +83,8 @@ int make_beacon_frame(int index, const unsigned char tx_addr[6], int seq_number, } static const unsigned char tim_bitmap[] = {0x01, 0x02, 0x00, 0x00}; - if (libwifi_quick_add_tag(&beacon.tags, TAG_TIM, tim_bitmap, 4)) { + if (libwifi_quick_add_tag(&beacon.tags, TAG_TIM, tim_bitmap, 4)) + { printf("Could not add TIM tag.\n"); return -7; } @@ -134,88 +138,17 @@ int make_beacon_frame(int index, const unsigned char tx_addr[6], int seq_number, return beacon_size; } -int prepend_radiotap(const unsigned char *input, int input_size, unsigned char **output) -{ - static const unsigned char radiotap[] = "\x00\x00\x08\x00\x00\x00\x00\x00"; - static const int radiotap_size = 8; - - int output_size = input_size + radiotap_size; - - unsigned char *buf = (unsigned char *)malloc(output_size); - if (buf == NULL) - { - return -1; - } - - memcpy(buf, radiotap, radiotap_size); - memcpy(buf + radiotap_size, input, input_size); - - *output = buf; - - return output_size; -} - -int send_packet(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size) -{ - struct sockaddr_ll socket_address; - socket_address.sll_ifindex = device_index; - socket_address.sll_halen = ETH_ALEN; - memcpy(socket_address.sll_addr, dst_addr, 6); - - pthread_mutex_lock(&socket_mutex); - - int ret = 0; - if (sendto(sock, packet, packet_size, 0, (struct sockaddr *)&socket_address, sizeof(struct sockaddr_ll)) < 0) - { - printf("Could not send packet: %d\n", errno); - ret = errno; - } - - pthread_mutex_unlock(&socket_mutex); - - return ret; -} - -int send_packet_with_radiotap(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size) -{ - struct libwifi_radiotap_info radiotap_info = {0}; - radiotap_info.present = (1 << IEEE80211_RADIOTAP_FLAGS) | (1 << IEEE80211_RADIOTAP_RATE); - radiotap_info.flags = IEEE80211_RADIOTAP_F_FCS | IEEE80211_RADIOTAP_F_SHORTPRE; - radiotap_info.rate_raw = 4; - - unsigned char radiotap_buffer[256]; - int radiotap_size = libwifi_create_radiotap(&radiotap_info, radiotap_buffer); - - uint32_t fcs = libwifi_calculate_fcs(packet, packet_size); - - int buffer_size = radiotap_size + packet_size + sizeof(uint32_t); - unsigned char *buffer = malloc(buffer_size); - if (buffer == NULL) - { - printf("Could not prepend radiotap.\n"); - return -2; - } - - memcpy(buffer, radiotap_buffer, radiotap_size); - memcpy(buffer + radiotap_size, packet, packet_size); - memcpy(buffer + radiotap_size + packet_size, (unsigned char*)&fcs, sizeof(uint32_t)); - - int ret = send_packet(sock, device_index, dst_addr, buffer, buffer_size); - free(buffer); - - return ret; -} - int send_ack(int sock, int device_index, const unsigned char dst_addr[6]) { struct libwifi_cts ack_frame = {0}; - if (libwifi_create_cts(&ack_frame, dst_addr, 0)) { + if (libwifi_create_cts(&ack_frame, dst_addr, 0)) + { printf("Could not create ack packet.\n"); } ack_frame.frame_header.frame_control.subtype = SUBTYPE_ACK; - int ret = send_packet_with_radiotap(sock, device_index, dst_addr, (unsigned char*)&ack_frame, sizeof(struct libwifi_cts)); + int ret = send_packet_with_radiotap(sock, device_index, dst_addr, (unsigned char *)&ack_frame, sizeof(struct libwifi_cts)); return ret; } @@ -232,10 +165,22 @@ struct thread_info int sock; unsigned char tx_addr[6]; int device_index; + struct retransmitter *retransmitter; struct addr_list authenticated; }; +enum auth_state +{ + kAuthStateAuthenticated, + kAuthStateAssociated, +}; + +struct auth_info +{ + enum auth_state auth_state; +}; + void handle_incoming_packet(u_char *userdata, const struct pcap_pkthdr *h, const u_char *bytes) { struct thread_info *tinfo = (struct thread_info *)userdata; @@ -249,7 +194,8 @@ void handle_incoming_packet(u_char *userdata, const struct pcap_pkthdr *h, const if (frame.frame_control.type == TYPE_MANAGEMENT && frame.frame_control.subtype == SUBTYPE_AUTH) { - if (strncmp(frame.header.data.addr1, tinfo->tx_addr, 6)) { + if (strncmp(frame.header.data.addr1, tinfo->tx_addr, 6)) + { // This is not for me. Misdelivery. return; } @@ -271,11 +217,14 @@ void handle_incoming_packet(u_char *userdata, const struct pcap_pkthdr *h, const return; } - //usleep(frame.header.ctrl.duration / 2 * 100); + // usleep(frame.header.ctrl.duration / 2 * 100); send_ack(tinfo->sock, tinfo->device_index, frame.header.data.addr2); - addr_list_add(&tinfo->authenticated, frame.header.data.addr2); + struct auth_info *ainfo = (struct auth_info *)malloc(sizeof(struct auth_info)); + ainfo->auth_state = kAuthStateAuthenticated; + + addr_list_add(&tinfo->authenticated, frame.header.data.addr2, ainfo); struct libwifi_auth auth_resp = {0}; if (libwifi_create_auth(&auth_resp, frame.header.data.addr2, frame.header.data.addr1, frame.header.data.addr1, AUTH_OPEN, 2, STATUS_SUCCESS)) @@ -287,8 +236,8 @@ void handle_incoming_packet(u_char *userdata, const struct pcap_pkthdr *h, const auth_resp.frame_header.duration = frame.header.ctrl.duration; auth_resp.frame_header.seq_control.sequence_number = get_next_seq_number(); - //static const unsigned char broadcom_tag_value[] = {0x00, 0x10, 0x18, 0x02, 0x00, 0xf0, 0x00, 0x00, 0x00}; - //libwifi_quick_add_tag(&auth_resp.tags, TAG_VENDOR_SPECIFIC, broadcom_tag_value, 9); + // static const unsigned char broadcom_tag_value[] = {0x00, 0x10, 0x18, 0x02, 0x00, 0xf0, 0x00, 0x00, 0x00}; + // libwifi_quick_add_tag(&auth_resp.tags, TAG_VENDOR_SPECIFIC, broadcom_tag_value, 9); size_t auth_resp_size = libwifi_get_auth_length(&auth_resp); unsigned char *auth_resp_output = (unsigned char *)malloc(auth_resp_size); @@ -306,23 +255,73 @@ void handle_incoming_packet(u_char *userdata, const struct pcap_pkthdr *h, const libwifi_free_auth(&auth_resp); - //usleep(frame.header.ctrl.duration * 100); + // usleep(frame.header.ctrl.duration * 100); + + send_until_acked(tinfo->retransmitter, frame.header.data.addr2, auth_resp_output, auth_resp_size); - if (send_packet_with_radiotap(tinfo->sock, tinfo->device_index, frame.header.data.addr2, auth_resp_output, auth_resp_size)) + printf("Successfully authenticated %s!\n", in_addr); + } + else if (frame.frame_control.type == TYPE_CONTROL && frame.frame_control.subtype == SUBTYPE_ACK) + { + if (strncmp(frame.body, tinfo->tx_addr, 6)) { - printf("Could not send auth response.\n"); + // This is not for me. Misdelivery. return; } - usleep(5000); + handle_ack(tinfo->retransmitter); + } + else if (frame.frame_control.type == TYPE_MANAGEMENT && frame.frame_control.subtype == SUBTYPE_ASSOC_REQ) + { + if (strncmp(frame.header.data.addr1, tinfo->tx_addr, 6)) + { + // This is not for me. Misdelivery. + return; + } - if (send_packet_with_radiotap(tinfo->sock, tinfo->device_index, frame.header.data.addr2, auth_resp_output, auth_resp_size)) + unsigned char in_addr[18]; + format_mac_address(frame.header.data.addr2, in_addr); + printf("Association request from %s\n", in_addr); + + if (!addr_list_contains(&tinfo->authenticated, frame.header.data.addr2)) { - printf("Could not send auth response.\n"); + // Not authenticated. return; } - printf("Successfully authenticated %s!\n", in_addr); + struct auth_info *ainfo = addr_list_get(&tinfo->authenticated, frame.header.data.addr2); + if (ainfo->auth_state != kAuthStateAuthenticated) + { + // Already associated. + return; + } + + send_ack(tinfo->sock, tinfo->device_index, frame.header.data.addr2); + + ainfo->auth_state = kAuthStateAssociated; + + struct libwifi_assoc_resp assoc_resp = {0}; + if (libwifi_create_assoc_resp(&assoc_resp, frame.header.data.addr2, tinfo->tx_addr, tinfo->tx_addr, CHANNEL_NUM)) + { + printf("Could not create assoc response.\n"); + return; + } + + assoc_resp.frame_header.seq_control.sequence_number = get_next_seq_number(); + + size_t assoc_resp_length = libwifi_get_assoc_resp_length(&assoc_resp); + unsigned char *assoc_resp_buffer = malloc(assoc_resp_length); + if (libwifi_dump_assoc_resp(&assoc_resp, assoc_resp_buffer, assoc_resp_length) < 0) + { + printf("Could not dump assoc response.\n"); + return; + } + + libwifi_free_assoc_resp(&assoc_resp); + + send_until_acked(tinfo->retransmitter, frame.header.data.addr2, assoc_resp_buffer, assoc_resp_length); + + printf("Successfully associated with %s!\n", in_addr); } } @@ -330,31 +329,6 @@ void *polling_thread(void *arg) { struct thread_info *tinfo = (struct thread_info *)arg; - /*for (;;) { - struct pollfd pfd; - pfd.fd = tinfo->sock; - pfd.events = POLLIN; - - if (poll(&pfd, 1, -1) < 0) { - printf("Error polling.\n"); - } else { - if (pfd.revents & POLLIN) { - unsigned char message[1024]; - int msglen = read(tinfo->sock, message, 1024); - if (msglen < 0) { - printf("Could not read from socket.\n"); - } else { - struct libwifi_frame frame = {0}; - if (libwifi_get_wifi_frame(&frame, message, msglen, true)) { - printf("Could not parse frame.\n"); - } else { - printf("Frame type: %d:%d\n", frame.frame_control.type, frame.frame_control.subtype); - } - } - } - } - }*/ - char errbuf[PCAP_ERRBUF_SIZE]; pcap_t *sniffer = pcap_create("mon0", errbuf); if (sniffer == NULL) @@ -396,21 +370,16 @@ int main(int argc, char **argv) return 2; } + struct retransmitter *retransmitter = start_retransmit_thread(sock, device_index); + struct thread_info *tinfo = (struct thread_info *)malloc(sizeof(struct thread_info *)); tinfo->sock = sock; memcpy(tinfo->tx_addr, tx_addr, 6); tinfo->device_index = device_index; + tinfo->retransmitter = retransmitter; addr_list_init(&tinfo->authenticated); - pthread_attr_t thread_attr; - if (pthread_attr_init(&thread_attr)) - { - printf("Could not initialize thread attr.\n"); - return 6; - } - - pthread_create(&tinfo->thread_id, &thread_attr, &polling_thread, tinfo); - pthread_attr_destroy(&thread_attr); + pthread_create(&tinfo->thread_id, NULL, &polling_thread, tinfo); int beacon_index = 0; for (;;) diff --git a/src/retransmit.c b/src/retransmit.c new file mode 100644 index 0000000..44f609c --- /dev/null +++ b/src/retransmit.c @@ -0,0 +1,169 @@ +#include "retransmit.h" + +#include +#include +#include +#include +#include + +#include "transmit.h" + +static pthread_mutex_t retransmitter_mutex = PTHREAD_MUTEX_INITIALIZER; + +void ack_map_init(struct ack_map *map) +{ + map->top = NULL; +} + +void ack_map_add(struct ack_map *map, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size) +{ + struct ack_map_node *cur = map->top; + struct ack_map_node *prev = NULL; + + while (cur != NULL) + { + prev = cur; + cur = cur->next; + } + + struct ack_map_node *next = (struct ack_map_node *)malloc(sizeof(struct ack_map_node)); + next->next = NULL; + memcpy(next->dst_addr, dst_addr, 6); + next->packet = (unsigned char *)malloc(packet_size); + memcpy(next->packet, packet, packet_size); + next->packet_size = packet_size; + next->retries_left = 7; + + if (prev == NULL) + { + map->top = next; + } + else + { + prev->next = next; + } +} + +void ack_map_pop(struct ack_map *map) +{ + if (map->top != NULL) + { + struct ack_map_node *cur = map->top; + map->top = cur->next; + + free(cur->packet); + free(cur); + } +} + +int ack_map_length(struct ack_map *map) +{ + int result = 0; + + struct ack_map_node *cur = map->top; + while (cur != NULL) + { + result++; + + cur = cur->next; + } + + return result; +} + +void ack_map_clear(struct ack_map *map) +{ + while (map->top != NULL) + { + ack_map_pop(map); + } +} + +void *retransmit_thread(void *arg) +{ + struct retransmitter *retransmitter = (struct retransmitter *)arg; + + for (;;) + { + pthread_mutex_lock(&retransmitter_mutex); + + if (retransmitter->quit) + { + pthread_mutex_unlock(&retransmitter_mutex); + + break; + } + + struct ack_map_node *cur = retransmitter->messages.top; + if (cur != NULL) + { + send_packet_with_radiotap(retransmitter->sock, retransmitter->device_index, cur->dst_addr, cur->packet, cur->packet_size); + + // Set retransmit flag for future. + cur->packet[1] |= (1 << 3); + + cur->retries_left--; + + if (cur->retries_left <= 0) + { + ack_map_pop(&retransmitter->messages); + } + } + + pthread_mutex_unlock(&retransmitter_mutex); + + usleep(5000); + } + + return NULL; +} + +struct retransmitter *start_retransmit_thread(int sock, int device_index) +{ + struct retransmitter *retransmitter = (struct retransmitter *)malloc(sizeof(struct retransmitter)); + retransmitter->sock = sock; + retransmitter->device_index = device_index; + ack_map_init(&retransmitter->messages); + retransmitter->quit = false; + + pthread_create(&retransmitter->thread_id, NULL, &retransmit_thread, retransmitter); + + return retransmitter; +} + +void send_until_acked(struct retransmitter *retransmitter, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size) +{ + pthread_mutex_lock(&retransmitter_mutex); + + ack_map_add(&retransmitter->messages, dst_addr, packet, packet_size); + + printf("Adding message for " MACSTR ". Current length: %d\n", MAC2STR(dst_addr), ack_map_length(&retransmitter->messages)); + + pthread_mutex_unlock(&retransmitter_mutex); +} + +void handle_ack(struct retransmitter *retransmitter) +{ + pthread_mutex_lock(&retransmitter_mutex); + + if (retransmitter->messages.top != NULL) + { + retransmitter->messages.top->retries_left = 0; + } + + printf("Received ACK. Current length: %d\n", ack_map_length(&retransmitter->messages)); + + pthread_mutex_unlock(&retransmitter_mutex); +} + +void free_retransmitter(struct retransmitter *retransmitter) +{ + pthread_mutex_lock(&retransmitter_mutex); + retransmitter->quit = true; + pthread_mutex_unlock(&retransmitter_mutex); + + pthread_join(retransmitter->thread_id, NULL); + + ack_map_clear(&retransmitter->messages); + free(retransmitter); +} diff --git a/src/retransmit.h b/src/retransmit.h new file mode 100644 index 0000000..0d2a90b --- /dev/null +++ b/src/retransmit.h @@ -0,0 +1,32 @@ +#ifndef G4U_RETRANSMIT_H +#define G4U_RETRANSMIT_H + +#include +#include + +struct ack_map_node { + unsigned char dst_addr[6]; + unsigned char* packet; + int packet_size; + int retries_left; + struct ack_map_node* next; +}; + +struct ack_map { + struct ack_map_node* top; +}; + +struct retransmitter { + pthread_t thread_id; + int sock; + int device_index; + struct ack_map messages; + bool quit; +}; + +struct retransmitter* start_retransmit_thread(int sock, int device_index); +void send_until_acked(struct retransmitter* retransmitter, const unsigned char dst_addr[6], const unsigned char* packet, int packet_size); +void handle_ack(struct retransmitter* retransmitter); +void free_retransmitter(struct retransmitter* retransmitter); + +#endif /* G4U_RETRANSMIT_H */ diff --git a/src/transmit.c b/src/transmit.c new file mode 100644 index 0000000..1978ff2 --- /dev/null +++ b/src/transmit.c @@ -0,0 +1,55 @@ +#include "transmit.h" + +#include +#include +#include +#include +#include +#include + +static pthread_mutex_t socket_mutex = PTHREAD_MUTEX_INITIALIZER; + +int send_packet(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size) +{ + struct sockaddr_ll socket_address; + socket_address.sll_ifindex = device_index; + socket_address.sll_halen = ETH_ALEN; + memcpy(socket_address.sll_addr, dst_addr, 6); + + pthread_mutex_lock(&socket_mutex); + + int ret = 0; + if (sendto(sock, packet, packet_size, 0, (struct sockaddr *)&socket_address, sizeof(struct sockaddr_ll)) < 0) + { + printf("Could not send packet: %d\n", errno); + ret = errno; + } + + pthread_mutex_unlock(&socket_mutex); + + return ret; +} + +int send_packet_with_radiotap(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char* packet, int packet_size) +{ + struct libwifi_radiotap_info radiotap_info = {0}; + radiotap_info.present = (1 << IEEE80211_RADIOTAP_FLAGS) | (1 << IEEE80211_RADIOTAP_RATE); + radiotap_info.flags = IEEE80211_RADIOTAP_F_FCS | IEEE80211_RADIOTAP_F_SHORTPRE; + radiotap_info.rate_raw = 4; + + unsigned char radiotap_buffer[256]; + int radiotap_size = libwifi_create_radiotap(&radiotap_info, radiotap_buffer); + + uint32_t fcs = libwifi_calculate_fcs(packet, packet_size); + + int buffer_size = radiotap_size + packet_size + sizeof(uint32_t); + unsigned char* buffer = (unsigned char*)malloc(buffer_size); + + memcpy(buffer, radiotap_buffer, radiotap_size); + memcpy(buffer + radiotap_size, packet, packet_size); + memcpy(buffer + radiotap_size + packet_size, (unsigned char*)&fcs, sizeof(uint32_t)); + + int ret = send_packet(sock, device_index, dst_addr, buffer, buffer_size); + + return ret; +} diff --git a/src/transmit.h b/src/transmit.h new file mode 100644 index 0000000..f095586 --- /dev/null +++ b/src/transmit.h @@ -0,0 +1,6 @@ +#ifndef G4U_TRANSMIT_H +#define G4U_TRANSMIT_H + +int send_packet_with_radiotap(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char* packet, int packet_size); + +#endif /* G4U_TRANSMIT_H */ -- cgit 1.4.1