#include <string.h>
#include <ctype.h>
#include <unistd.h>
+#include <fcntl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
-#include <pthread.h>
+#include <sys/select.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#include "ftraceroute.h"
#include "options.h"
-double version = 0.1;
-
-/* Mutex for synchronized output to stdout */
-pthread_mutex_t log_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-/* Struct to pass arguments to the thread */
-typedef struct {
- char *host;
- int max_hops;
- int probes;
- int timeout_ms;
- uint16_t thread_id; /* Unique ID for ICMP correlation */
-} trace_args_t;
+double version = 0.2;
int main(int argc, char **argv) {
if (probes <= 0) probes = DEFAULT_PROBES;
int num_hosts = argc - optind;
- pthread_t *threads = malloc(sizeof(pthread_t) * num_hosts);
- trace_args_t *t_args = malloc(sizeof(trace_args_t) * num_hosts);
+ trace_session_t *sessions = calloc(num_hosts, sizeof(trace_session_t));
+ // Initialization of all sessions
for (int i = 0; i < num_hosts; i++) {
- t_args[i].host = argv[optind + i];
- t_args[i].max_hops = max_hops;
- t_args[i].probes = probes;
- t_args[i].timeout_ms = timeout_ms;
- // Generate a unique ID for this thread (mix PID and index) to separate ICMP replies
- t_args[i].thread_id = (getpid() & 0xFF00) | ((i + 1) & 0x00FF);
-
- if (pthread_create(&threads[i], NULL, run_trace, &t_args[i]) != 0) {
- perror("pthread_create");
- }
+ session_init(&sessions[i], argv[optind + i], max_hops, probes, timeout_ms, i);
}
- // Wait for all threads to finish
- for (int i = 0; i < num_hosts; i++) {
- pthread_join(threads[i], NULL);
+ // Main loop (event loop)
+ while (1) {
+ int active_count = 0;
+ int max_fd = -1;
+ fd_set readfds;
+ FD_ZERO(&readfds);
+
+ // 1. Collect FDs for select
+ for (int i = 0; i < num_hosts; i++) {
+ trace_session_t *s = &sessions[i];
+ if (s->state == STATE_FINISHED || s->state == STATE_ERROR) continue;
+ active_count++;
+
+ // While waiting for a response, we add the socket to the read set.
+ if (s->state == STATE_AWAIT_REPLY && s->sock >= 0) {
+ FD_SET(s->sock, &readfds);
+ if (s->sock > max_fd) max_fd = s->sock;
+ }
+ }
+ if (active_count == 0) break;
+
+ // 2. Select with a short timeout (10 ms) so that we can check send/timeouts.
+ struct timeval tv;
+ tv.tv_sec = 0;
+ tv.tv_usec = 10000;
+ select(max_fd + 1, &readfds, NULL, NULL, &tv);
+
+ // 3. Processing for all sessions
+ for (int i = 0; i < num_hosts; i++) {
+ trace_session_t *s = &sessions[i];
+ if (s->state == STATE_FINISHED || s->state == STATE_ERROR) continue;
+
+ // A) Read (if data is available)
+ if (s->state == STATE_AWAIT_REPLY && s->sock >= 0 && FD_ISSET(s->sock, &readfds)) {
+ process_read(s);
+ }
+
+ // B) Timeout check (if still waiting)
+ if (s->state == STATE_AWAIT_REPLY) {
+ process_timeout_check(s);
+ }
+
+ // C) Preparing a new hop
+ if (s->state == STATE_PREPARE_HOP) {
+ s->current_ttl++;
+ if (s->current_ttl > s->max_hops) {
+ fprintf(stderr, "[%s] Target not reached (max_hops=%d).\n", s->host_arg, s->max_hops);
+ s->state = STATE_FINISHED;
+ session_close(s);
+ } else {
+ // Initialize output buffer
+ s->line_off = 0;
+ s->line_off += snprintf(s->line_buf + s->line_off, sizeof(s->line_buf) - s->line_off, "[%s] %2d ", s->host_arg, s->current_ttl);
+
+ // Set socket TTL
+ if (s->dst.ss_family == AF_INET) {
+ setsockopt(s->sock, IPPROTO_IP, IP_TTL, &s->current_ttl, sizeof(s->current_ttl));
+ } else {
+ setsockopt(s->sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &s->current_ttl, sizeof(s->current_ttl));
+ }
+
+ s->current_probe = 0;
+ s->printed_addr = false;
+ s->state = STATE_SEND_PROBE;
+ }
+ }
+
+ // D) Send (when ready)
+ if (s->state == STATE_SEND_PROBE) {
+ process_send(s);
+ }
+ }
}
- free(threads);
- free(t_args);
+ free(sessions);
return 0;
}
-void *run_trace(void *arg) {
- trace_args_t *args = (trace_args_t *)arg;
- // Resolve Host (IPv4 or IPv6)
- struct sockaddr_storage dst_store;
- if (resolve_host(args->host, &dst_store) < 0) return NULL;
+/*
+ * Functions
+ */
+
+void session_init(trace_session_t *s, char *host, int mh, int pp, int tm, int idx) {
+ s->host_arg = host;
+ s->max_hops = mh;
+ s->probes_per_hop = pp;
+ s->timeout_ms = tm;
+ s->current_ttl = 0;
+ s->reached_dest = false;
+ s->ident = (getpid() & 0xFFFF) + idx; // Unique ID per session
+ s->seq_base = 0;
+
+ if (resolve_host(host, &s->dst) < 0) {
+ fprintf(stderr, "[%s] Could not resolve host.\n", host);
+ s->state = STATE_ERROR;
+ s->sock = -1;
+ return;
+ }
+
+ s->dst_len = (s->dst.ss_family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
+ s->proto = (s->dst.ss_family == AF_INET) ? IPPROTO_ICMP : IPPROTO_ICMPV6;
- struct sockaddr *dst = (struct sockaddr *)&dst_store;
- socklen_t dst_len = (dst->sa_family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
char dst_ip[INET6_ADDRSTRLEN];
- getnameinfo(dst, dst_len, NULL, 0, dst_ip, sizeof(dst_ip), NI_NUMERICHOST);
-
- pthread_mutex_lock(&log_mutex);
- printf("[%s] Start traceroute to %s (%s)\n", args->host, args->host, dst_ip);
- pthread_mutex_unlock(&log_mutex);
-
- // Choose Protocol based on family
- int proto = (dst->sa_family == AF_INET) ? IPPROTO_ICMP : IPPROTO_ICMPV6;
-
- int sock = socket(dst->sa_family, SOCK_RAW, proto);
- if (sock < 0) {
- // Output error protected by mutex
- pthread_mutex_lock(&log_mutex);
- fprintf(stderr, "[%s] ", args->host);
- perror("socket creation failed");
- pthread_mutex_unlock(&log_mutex);
- return NULL;
+ getnameinfo((struct sockaddr *)&s->dst, s->dst_len, NULL, 0, dst_ip, sizeof(dst_ip), NI_NUMERICHOST);
+ printf("[%s] Start traceroute to %s (%s)\n", host, host, dst_ip);
+
+
+
+ s->sock = socket(s->dst.ss_family, SOCK_RAW, s->proto);
+ if (s->sock < 0) {
+ perror("socket");
+ s->state = STATE_ERROR;
+ return;
}
- // Set recv timeout
- struct timeval tv;
- tv.tv_sec = args->timeout_ms / 1000;
- tv.tv_usec = (args->timeout_ms % 1000) * 1000;
- if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0) {
- perror("setsockopt(SO_RCVTIMEO)");
+ // IMPORTANT: Non-blocking for single-threaded event loop
+ int flags = fcntl(s->sock, F_GETFL, 0);
+ fcntl(s->sock, F_SETFL, flags | O_NONBLOCK);
+
+ s->state = STATE_PREPARE_HOP;
+}
+
+void session_close(trace_session_t *s) {
+ if (s->sock >= 0) {
+ close(s->sock);
+ s->sock = -1;
}
+}
- // Use the unique thread_id assigned in main instead of just getpid()
- unsigned short ident = args->thread_id;
- unsigned short seq_base = 0;
- bool reached = false;
-
- for (int ttl = 1; ttl <= args->max_hops && !reached; ++ttl) {
- if (dst->sa_family == AF_INET) {
- if (setsockopt(sock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
- perror("setsockopt(IP_TTL)");
- close(sock);
- return NULL;
- }
+void process_send(trace_session_t *s) {
+ if (s->current_probe >= s->probes_per_hop) {
+ flush_line(s);
+ if (s->reached_dest) {
+ s->state = STATE_FINISHED;
+ session_close(s);
} else {
- if (setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
- perror("setsockopt(IPV6_UNICAST_HOPS)");
- close(sock);
- return NULL;
- }
+ s->state = STATE_PREPARE_HOP;
}
+ return;
+ }
- // Create buffer for entire line to prevent “mixed output”
- char line_buf[2048];
- size_t off = 0;
- off += snprintf(line_buf + off, sizeof(line_buf) - off, "[%s] %2d ", args->host, ttl);
-
- bool printed_addr = false;
-
- for (int p = 0; p < args->probes; ++p) {
- unsigned char packet[PACKET_SIZE];
- memset(packet, 0, sizeof(packet));
- size_t pkt_len = 0;
+ unsigned char packet[PACKET_SIZE];
+ memset(packet, 0, sizeof(packet));
+ size_t pkt_len = 0;
+ struct timeval *stamp_ptr = NULL;
+
+ if (s->dst.ss_family == AF_INET) {
+ struct icmphdr *icmp = (struct icmphdr *)packet;
+ icmp->type = ICMP_ECHO;
+ icmp->code = 0;
+ icmp->un.echo.id = htons(s->ident);
+ icmp->un.echo.sequence = htons(s->seq_base++);
+
+ stamp_ptr = (struct timeval *)(packet + sizeof(struct icmphdr));
+ pkt_len = sizeof(struct icmphdr) + sizeof(struct timeval);
+ gettimeofday(stamp_ptr, NULL);
+ icmp->checksum = 0;
+ icmp->checksum = checksum(packet, (int)pkt_len);
+ } else {
+ struct icmp6_hdr *icmp6 = (struct icmp6_hdr *)packet;
+ icmp6->icmp6_type = ICMP6_ECHO_REQUEST;
+ icmp6->icmp6_code = 0;
+ icmp6->icmp6_id = htons(s->ident);
+ icmp6->icmp6_seq = htons(s->seq_base++);
+
+ stamp_ptr = (struct timeval *)(packet + sizeof(struct icmp6_hdr));
+ pkt_len = sizeof(struct icmp6_hdr) + sizeof(struct timeval);
+ gettimeofday(stamp_ptr, NULL);
+ }
- struct timeval *stamp_ptr = NULL;
+ gettimeofday(&s->t_send, NULL);
+ if (sendto(s->sock, packet, pkt_len, 0, (struct sockaddr *)&s->dst, s->dst_len) < 0) {
+ if (errno != EAGAIN && errno != EWOULDBLOCK) {
+ s->line_off += snprintf(s->line_buf + s->line_off, sizeof(s->line_buf) - s->line_off, "* ");
+ s->current_probe++;
+ return;
+ }
+ }
+ s->state = STATE_AWAIT_REPLY;
+}
- // Build Packet
- if (dst->sa_family == AF_INET) {
- struct icmphdr *icmp = (struct icmphdr *)packet;
- icmp->type = ICMP_ECHO;
- icmp->code = 0;
- icmp->un.echo.id = htons(ident);
- icmp->un.echo.sequence = htons(seq_base++);
-
- stamp_ptr = (struct timeval *)(packet + sizeof(struct icmphdr));
- pkt_len = sizeof(struct icmphdr) + sizeof(struct timeval);
-
- gettimeofday(stamp_ptr, NULL);
- icmp->checksum = 0;
- icmp->checksum = checksum(packet, (int)pkt_len);
- } else {
- // IPv6 ICMP Header construction
- struct icmp6_hdr *icmp6 = (struct icmp6_hdr *)packet;
- icmp6->icmp6_type = ICMP6_ECHO_REQUEST;
- icmp6->icmp6_code = 0;
- icmp6->icmp6_id = htons(ident);
- icmp6->icmp6_seq = htons(seq_base++);
-
- stamp_ptr = (struct timeval *)(packet + sizeof(struct icmp6_hdr));
- pkt_len = sizeof(struct icmp6_hdr) + sizeof(struct timeval);
-
- gettimeofday(stamp_ptr, NULL);
- // NOTE: Kernel calculates Checksum for ICMPv6 RAW sockets!
- icmp6->icmp6_cksum = 0;
- }
+void process_timeout_check(trace_session_t *s) {
+ struct timeval now;
+ gettimeofday(&now, NULL);
+ double elapsed = ms_between(s->t_send, now);
+ if (elapsed > s->timeout_ms) {
+ s->line_off += snprintf(s->line_buf + s->line_off, sizeof(s->line_buf) - s->line_off, "* ");
+ s->current_probe++;
+ s->state = STATE_SEND_PROBE;
+ }
+}
- struct timeval t_send;
- gettimeofday(&t_send, NULL);
- if (sendto(sock, packet, pkt_len, 0, dst, dst_len) < 0) {
- perror("sendto");
- if (off < sizeof(line_buf)) {
- off += snprintf(line_buf + off, sizeof(line_buf) - off, "* ");
+void process_read(trace_session_t *s) {
+ unsigned char recvbuf[PACKET_SIZE];
+ struct sockaddr_storage reply_addr;
+ socklen_t rlen = sizeof(reply_addr);
+ struct timeval t_rcv;
+
+ ssize_t n = recvfrom(s->sock, recvbuf, sizeof(recvbuf), 0, (struct sockaddr *)&reply_addr, &rlen);
+ if (n < 0) return;
+
+ gettimeofday(&t_rcv, NULL);
+ bool match = false;
+ bool is_final = false;
+
+ if (s->dst.ss_family == AF_INET) {
+ struct iphdr *ip = (struct iphdr *)recvbuf;
+ int iphdrlen = ip->ihl * 4;
+ if (n >= iphdrlen + 8) {
+ struct icmphdr *icmph = (struct icmphdr *)(recvbuf + iphdrlen);
+ if (icmph->type == ICMP_ECHOREPLY) {
+ if (ntohs(icmph->un.echo.id) == s->ident && ntohs(icmph->un.echo.sequence) == (unsigned short)(s->seq_base - 1)) {
+ match = true; is_final = true;
}
- continue;
- }
- // Receive Loop
- unsigned char recvbuf[PACKET_SIZE];
- for (;;) {
- struct sockaddr_storage reply_addr;
- socklen_t rlen = sizeof(reply_addr);
- struct timeval t_rcv;
-
- ssize_t n = recvfrom(sock, recvbuf, sizeof(recvbuf), 0, (struct sockaddr *)&reply_addr, &rlen);
-
- if (n < 0) {
- if (errno == EAGAIN || errno == EWOULDBLOCK) {
- if (off < sizeof(line_buf)) {
- off += snprintf(line_buf + off, sizeof(line_buf) - off, "* ");
- }
- break;
- } else {
- perror("recvfrom");
- break;
+ } else if (icmph->type == ICMP_TIME_EXCEEDED) {
+ unsigned char *inner = (unsigned char *)icmph + 8;
+ struct iphdr *ip2 = (struct iphdr *)inner;
+ int ip2len = ip2->ihl * 4;
+ if (n >= iphdrlen + 8 + ip2len + 8) {
+ struct icmphdr *icmp2 = (struct icmphdr *)(inner + ip2len);
+ if (ntohs(icmp2->un.echo.id) == s->ident && ntohs(icmp2->un.echo.sequence) == (unsigned short)(s->seq_base - 1)) {
+ match = true;
}
}
- gettimeofday(&t_rcv, NULL);
-
- bool match = false;
- bool final_reply = false;
-
- // --- Parsing Response ---
- if (dst->sa_family == AF_INET) {
- // IPv4: RAW socket delivers IP header + payload
- struct iphdr *ip = (struct iphdr *)recvbuf;
- int iphdrlen = ip->ihl * 4;
- if (n < iphdrlen + 8) continue;
-
- struct icmphdr *icmph = (struct icmphdr *)(recvbuf + iphdrlen);
-
- if (icmph->type == ICMP_ECHOREPLY) {
- if (ntohs(icmph->un.echo.id) == ident && ntohs(icmph->un.echo.sequence) == (unsigned short)(seq_base - 1)) {
- match = true;
- final_reply = true;
- }
- } else if (icmph->type == ICMP_TIME_EXCEEDED) {
- // Inner IP packet
- unsigned char *inner = (unsigned char *)icmph + 8;
- struct iphdr *ip2 = (struct iphdr *)inner;
- int ip2len = ip2->ihl * 4;
- if (n >= iphdrlen + 8 + ip2len + 8) {
- struct icmphdr *icmp2 = (struct icmphdr *)(inner + ip2len);
- if (ntohs(icmp2->un.echo.id) == ident && ntohs(icmp2->un.echo.sequence) == (unsigned short)(seq_base - 1)) {
- match = true;
- }
- }
- }
- } else {
- // IPv6: RAW socket normally delivers ONLY the ICMP header (without IPv6 header)
- // Check whether there is enough data for ICMPv6 headers
- if (n < (ssize_t)sizeof(struct icmp6_hdr)) continue;
-
- struct icmp6_hdr *icmp6h = (struct icmp6_hdr *)recvbuf;
-
- if (icmp6h->icmp6_type == ICMP6_ECHO_REPLY) {
- if (ntohs(icmp6h->icmp6_id) == ident && ntohs(icmp6h->icmp6_seq) == (unsigned short)(seq_base - 1)) {
- match = true;
- final_reply = true;
- }
- } else if (icmp6h->icmp6_type == ICMP6_TIME_EXCEEDED) {
- // Payload structure: [ICMP6 Header (8 bytes)] + [Original IPv6 Header (40 bytes)] + [Original ICMP6 Header Start]
- // Skip 8 (ICMP header) + 40 (inner IPv6 header) to get to the inner ICMP header.
- size_t offset_to_inner_icmp = sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr);
-
- if (n >= (ssize_t)(offset_to_inner_icmp + sizeof(struct icmp6_hdr))) {
- struct icmp6_hdr *inner_icmp = (struct icmp6_hdr *)(recvbuf + offset_to_inner_icmp);
- if (ntohs(inner_icmp->icmp6_id) == ident && ntohs(inner_icmp->icmp6_seq) == (unsigned short)(seq_base - 1)) {
- match = true;
- }
- }
- }
+ }
+ }
+ } else {
+ // IPv6
+ if (n >= (ssize_t)sizeof(struct icmp6_hdr)) {
+ struct icmp6_hdr *icmp6h = (struct icmp6_hdr *)recvbuf;
+ if (icmp6h->icmp6_type == ICMP6_ECHO_REPLY) {
+ if (ntohs(icmp6h->icmp6_id) == s->ident && ntohs(icmp6h->icmp6_seq) == (unsigned short)(s->seq_base - 1)) {
+ match = true;
+ is_final = true;
}
-
- if (!match) continue;
-
- if (!printed_addr) {
- char host_name[NI_MAXHOST] = {0};
- char ip_txt[INET6_ADDRSTRLEN] = {0};
-
- addr_to_host((struct sockaddr *)&reply_addr, rlen, host_name, sizeof(host_name), ip_txt, sizeof(ip_txt));
-
- // Write address to buffer (only for the first hit per hop)
- int written = 0;
- if (host_name[0] == '\0') {
- written = snprintf(line_buf + off, sizeof(line_buf) - off, "%s ", ip_txt);
- } else {
- written = snprintf(line_buf + off, sizeof(line_buf) - off, "%s (%s) ", host_name, ip_txt);
+ } else if (icmp6h->icmp6_type == ICMP6_TIME_EXCEEDED) {
+ size_t offset = sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr);
+ if (n >= (ssize_t)(offset + sizeof(struct icmp6_hdr))) {
+ struct icmp6_hdr *inner = (struct icmp6_hdr *)(recvbuf + offset);
+ if (ntohs(inner->icmp6_id) == s->ident && ntohs(inner->icmp6_seq) == (unsigned short)(s->seq_base - 1)) {
+ match = true;
}
- if (written > 0) off += written;
- printed_addr = true;
}
-
- double rtt_ms = ms_between(t_send, t_rcv);
- if (off < sizeof(line_buf)) {
- off += snprintf(line_buf + off, sizeof(line_buf) - off, "%.3f ms ", rtt_ms);
- }
-
- if (final_reply) reached = true;
- break; // Next probe
- }
- }
-
- // Now output the entire line atomically
- pthread_mutex_lock(&log_mutex);
- printf("%s\n", line_buf);
- pthread_mutex_unlock(&log_mutex);
- if (reached) break;
+ }
+ }
}
- if (!reached) {
- fprintf(stderr, "[%s] Ziel nicht erreicht (max_hops=%d).\n", args->host, args->max_hops);
- }
+ if (match) {
+ // Address buffering (once per hop)
+ if (!s->printed_addr) {
+ char host_name[NI_MAXHOST] = {0};
+ char ip_txt[INET6_ADDRSTRLEN] = {0};
+ addr_to_host((struct sockaddr *)&reply_addr, rlen, host_name, sizeof(host_name), ip_txt, sizeof(ip_txt));
- close(sock);
- return NULL;
+ if (host_name[0] == '\0') {
+ s->line_off += snprintf(s->line_buf + s->line_off, sizeof(s->line_buf) - s->line_off, "%s ", ip_txt);
+ } else {
+ s->line_off += snprintf(s->line_buf + s->line_off, sizeof(s->line_buf) - s->line_off, "%s (%s) ", host_name, ip_txt);
+ }
+ s->printed_addr = true;
+ }
+
+ double rtt = ms_between(s->t_send, t_rcv);
+ s->line_off += snprintf(s->line_buf + s->line_off, sizeof(s->line_buf) - s->line_off, "%.3f ms ", rtt);
+
+ if (is_final) s->reached_dest = true;
+
+ // Test successful -> Next test
+ s->current_probe++;
+ s->state = STATE_SEND_PROBE;
+ }
}
-/*
- * Functions
- */
+void flush_line(trace_session_t *s) {
+ printf("%s\n", s->line_buf);
+}
unsigned short checksum(void *b, int len) {
unsigned short *buf = b;
projects / ftraceroute.git / commitdiff