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#pragma once
#include <c-list.h>
#include <c-rbtree.h>
#include <errno.h>
#include <inttypes.h>
#include <netinet/if_ether.h>
#include <netinet/in.h>
#include <stdbool.h>
#include <stdlib.h>
#include "util/timer.h"
#include "n-acd.h"
typedef struct NAcdEventNode NAcdEventNode;
#define _cleanup_(_x) __attribute__((__cleanup__(_x)))
#define _public_ __attribute__((__visibility__("default")))
/* This augments the error-codes with internal ones that are never exposed. */
enum {
_N_ACD_INTERNAL = _N_ACD_E_N,
N_ACD_E_DROPPED,
};
enum {
N_ACD_PROBE_STATE_PROBING,
N_ACD_PROBE_STATE_CONFIGURING,
N_ACD_PROBE_STATE_ANNOUNCING,
N_ACD_PROBE_STATE_FAILED,
};
struct NAcdConfig {
int ifindex;
unsigned int transport;
uint8_t mac[ETH_ALEN];
size_t n_mac;
};
#define N_ACD_CONFIG_NULL(_x) { \
.transport = _N_ACD_TRANSPORT_N, \
}
struct NAcdProbeConfig {
struct in_addr ip;
uint64_t timeout_msecs;
};
#define N_ACD_PROBE_CONFIG_NULL(_x) { \
.timeout_msecs = N_ACD_TIMEOUT_RFC5227, \
}
struct NAcdEventNode {
CList acd_link;
CList probe_link;
NAcdEvent event;
uint8_t sender[ETH_ALEN];
bool is_public : 1;
};
#define N_ACD_EVENT_NODE_NULL(_x) { \
.acd_link = C_LIST_INIT((_x).acd_link), \
.probe_link = C_LIST_INIT((_x).probe_link), \
}
struct NAcd {
unsigned long n_refs;
unsigned int seed;
int fd_epoll;
int fd_socket;
CRBTree ip_tree;
CList event_list;
Timer timer;
/* BPF map */
int fd_bpf_map;
size_t n_bpf_map;
size_t max_bpf_map;
/* configuration */
int ifindex;
uint8_t mac[ETH_ALEN];
/* flags */
bool preempted : 1;
};
#define N_ACD_NULL(_x) { \
.n_refs = 1, \
.fd_epoll = -1, \
.fd_socket = -1, \
.ip_tree = C_RBTREE_INIT, \
.event_list = C_LIST_INIT((_x).event_list), \
.timer = TIMER_NULL((_x).timer), \
.fd_bpf_map = -1, \
}
struct NAcdProbe {
NAcd *acd;
CRBNode ip_node;
CList event_list;
Timeout timeout;
/* configuration */
struct in_addr ip;
uint64_t timeout_multiplier;
void *userdata;
/* state */
unsigned int state;
unsigned int n_iteration;
unsigned int defend;
uint64_t last_defend;
};
#define N_ACD_PROBE_NULL(_x) { \
.ip_node = C_RBNODE_INIT((_x).ip_node), \
.event_list = C_LIST_INIT((_x).event_list), \
.timeout = TIMEOUT_INIT((_x).timeout), \
.state = N_ACD_PROBE_STATE_PROBING, \
.defend = N_ACD_DEFEND_NEVER, \
}
/* events */
int n_acd_event_node_new(NAcdEventNode **nodep);
NAcdEventNode *n_acd_event_node_free(NAcdEventNode *node);
/* contexts */
void n_acd_remember(NAcd *acd, uint64_t now, bool success);
int n_acd_raise(NAcd *acd, NAcdEventNode **nodep, unsigned int event);
int n_acd_send(NAcd *acd, const struct in_addr *tpa, const struct in_addr *spa);
int n_acd_ensure_bpf_map_space(NAcd *acd);
/* probes */
int n_acd_probe_new(NAcdProbe **probep, NAcd *acd, NAcdProbeConfig *config);
int n_acd_probe_raise(NAcdProbe *probe, NAcdEventNode **nodep, unsigned int event);
int n_acd_probe_handle_timeout(NAcdProbe *probe);
int n_acd_probe_handle_packet(NAcdProbe *probe, struct ether_arp *packet, bool hard_conflict);
/* eBPF */
int n_acd_bpf_map_create(int *mapfdp, size_t max_elements);
int n_acd_bpf_map_add(int mapfd, struct in_addr *addr);
int n_acd_bpf_map_remove(int mapfd, struct in_addr *addr);
int n_acd_bpf_compile(int *progfdp, int mapfd, struct ether_addr *mac);
/* inline helpers */
static inline int n_acd_errno(void) {
/*
* Compilers continuously warn about uninitialized variables since they
* cannot deduce that `return -errno;` will always be negative. This
* small wrapper makes sure compilers figure that out. Use it as
* replacement for `errno` read access. Yes, it generates worse code,
* but only marginally and only affects slow-paths.
*/
return abs(errno) ? : EIO;
}
static inline void n_acd_event_node_freep(NAcdEventNode **node) {
if (*node)
n_acd_event_node_free(*node);
}
static inline void n_acd_closep(int *fdp) {
if (*fdp >= 0)
close(*fdp);
}
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