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-rw-r--r--.gitignore2
-rw-r--r--Makefile12
-rw-r--r--client.c10
-rw-r--r--clientd.c49
-rw-r--r--icmp.c184
-rw-r--r--icmp.h9
-rw-r--r--icmp_client.h23
-rw-r--r--icmp_server.h19
-rw-r--r--icmpd.c502
-rw-r--r--icmpd.h31
-rw-r--r--mt.c29
-rw-r--r--mt.h23
-rwxr-xr-xrun_server.sh2
-rw-r--r--server.c14
-rw-r--r--serverd.c73
-rw-r--r--util.c37
-rw-r--r--util.h4
17 files changed, 904 insertions, 119 deletions
diff --git a/.gitignore b/.gitignore
index 1c102fa..042f948 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
*.o
client
server
+clientd
+serverd
diff --git a/Makefile b/Makefile
index b1de31f..eadce97 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,8 @@
CC = gcc
-CFLAGS = -Wall -Wextra -O2 -g -std=c11 -fwrapv
+CFLAGS = -Wall -Wextra -O2 -g -std=c11 -fwrapv -pthread
+LDFLAGS = -pthread
-TARGETS = server client
+TARGETS = server client serverd clientd
SOURCES = $(filter-out $(patsubst %,%.c,$(TARGETS)),$(wildcard *.c))
OBJECTS = $(patsubst %.c,%.o,$(SOURCES))
@@ -14,11 +15,8 @@ clean:
rm -f $(TARGETS) *.o
-server: server.o $(OBJECTS)
- $(CC) $(CFLAGS) $^ -o $@
-
-client: client.o $(OBJECTS)
- $(CC) $(CFLAGS) $^ -o $@
+$(TARGETS): %: %.o $(OBJECTS)
+ $(CC) $^ -o $@ $(LDFLAGS)
%.o: %.c $(wildcard *.h)
$(CC) $(CFLAGS) -c -o $@ $<
diff --git a/client.c b/client.c
index 4c1a32f..aa9b13c 100644
--- a/client.c
+++ b/client.c
@@ -20,10 +20,14 @@ int main(void) {
// const char *ip_address = "192.168.43.220";
// const char *ip_address = "198.211.118.67"; // tomsmeding.com
- struct icmp_client_incoming reply =
- icmp_client_communicate(sock, ip_address, 42, 1234, "kaashandel", 10);
+ if (icmp_client_send(sock, inet_addr(ip_address), 1234, "kaashandel", 10) < 0) {
+ perror("icmp_client_send");
+ return 1;
+ }
+
+ struct icmp_incoming reply = icmp_client_receive(sock);
if (reply.data == NULL) {
- perror("icmp_client_communicate");
+ perror("icmp_client_receive");
return 1;
}
diff --git a/clientd.c b/clientd.c
new file mode 100644
index 0000000..a5e4d75
--- /dev/null
+++ b/clientd.c
@@ -0,0 +1,49 @@
+#define _GNU_SOURCE // getline
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/ip_icmp.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
+#include "icmpd.h"
+#include "util.h"
+
+int main(void) {
+ struct icmpd *d = icmpd_create_client(inet_addr("127.0.0.1"));
+
+ while (true) {
+ if (icmpd_peek(d)) {
+ struct icmpd_received msg = icmpd_recv(d);
+ printf("Recv: %zu\n", msg.length);
+ xxd(msg.data, msg.length);
+ }
+
+ fd_set inset;
+ FD_ZERO(&inset);
+ FD_SET(0, &inset);
+ struct timeval tv;
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+ int ret = select(1, &inset, NULL, NULL, &tv);
+ if (ret < 0) {
+ if (errno == EINTR) continue;
+ perror("select");
+ return 1;
+ }
+ if (ret == 0) continue; // timeout
+ if (FD_ISSET(0, &inset)) {
+ char *line = NULL;
+ size_t linelen = 0;
+ ssize_t nr = getline(&line, &linelen, stdin);
+ assert(nr >= 0);
+ if (nr > 0) nr--;
+ icmpd_send(d, line, nr);
+ free(line);
+ }
+ }
+}
diff --git a/icmp.c b/icmp.c
index bef1fd6..7951b91 100644
--- a/icmp.c
+++ b/icmp.c
@@ -21,6 +21,7 @@ static void make_sockaddr_u32(struct sockaddr_in *dst, uint32_t addr) {
dst->sin_addr.s_addr = addr;
}
+__attribute__((unused))
static void make_sockaddr(struct sockaddr_in *dst, const char *ip_address) {
make_sockaddr_u32(dst, inet_addr(ip_address));
}
@@ -43,6 +44,8 @@ static uint16_t compute_checksum(const void *buf_, size_t buflen) {
return res;
}
+// TODO: Maybe SOCK_{DGRAM,RAW} | SOCK_NONBLOCK to make non-blocking sockets;
+// this allows non-blocking reads in the icmpd thread.
int icmp_client_open_socket(void) {
return socket(PF_INET, SOCK_DGRAM, IPPROTO_ICMP);
}
@@ -51,72 +54,23 @@ int icmp_server_open_socket(void) {
return socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
}
-struct icmp_client_incoming icmp_client_communicate(
- int sock, const char *ip_address,
- int id, int seqnum,
- const void *data_, size_t length) {
-
- static uint8_t buffer[ICMP_MAX_PAYLOAD_LENGTH];
-
- const uint8_t *data = (const uint8_t*)data_;
-
- assert(length <= ICMP_MAX_PAYLOAD_LENGTH);
-
- struct icmp_client_incoming errret =
- (struct icmp_client_incoming){.data = NULL, .length = 0, .id = 0, .seqnum = 0};
+struct icmp_incoming icmp_client_communicate(
+ int sock, uint32_t addr,
+ int seqnum,
+ const void *data, size_t length) {
- struct sockaddr_in addr;
- make_sockaddr(&addr, ip_address);
-
- struct icmp_echo msg;
- memset(&msg, 0, sizeof msg);
- msg.type = ICMP_ECHO;
- msg.code = 0;
- msg.id = htons(id);
- msg.seqnum = htons(seqnum);
-
- memcpy(msg.payload, data, length);
-
- if (sendto(sock, &msg, ICMP_PAYLOAD_OFFSET + length, 0, (struct sockaddr*)&addr, sizeof addr) < 0) {
- return errret;
+ if (icmp_client_send(sock, addr, seqnum, data, length) < 0) {
+ return (struct icmp_incoming){.data = NULL, .length = 0, .id = 0, .seqnum = 0, .source_addr = 0};
}
- struct msghdr replyhdr;
- memset(&replyhdr, 0, sizeof replyhdr);
-
- struct iovec iov1;
- memset(&iov1, 0, sizeof iov1);
- iov1.iov_base = &msg;
- iov1.iov_len = sizeof msg;
-
- replyhdr.msg_name = &addr;
- replyhdr.msg_namelen = sizeof addr;
- replyhdr.msg_iov = &iov1;
- replyhdr.msg_iovlen = 1;
-
- ssize_t nr = recvmsg(sock, &replyhdr, 0);
- if (nr < 0) {
- return errret;
- }
-
- size_t payloadlen = nr - ICMP_PAYLOAD_OFFSET;
- assert(payloadlen <= MAX_DATAGRAM_SIZE);
-
- memcpy(buffer, msg.payload, payloadlen);
-
- return (struct icmp_client_incoming){
- .data = buffer,
- .length = payloadlen,
- .id = ntohs(msg.id),
- .seqnum = ntohs(msg.seqnum)
- };
+ return icmp_client_receive(sock);
}
-struct icmp_server_incoming icmp_server_receive(int sock) {
+struct icmp_incoming icmp_server_receive(int sock) {
static uint8_t buffer[ICMP_MAX_PAYLOAD_LENGTH];
- struct icmp_server_incoming errret =
- (struct icmp_server_incoming){.data = NULL, .length = 0, .id = 0, .seqnum = 0, .source_addr = 0};
+ struct icmp_incoming errret =
+ (struct icmp_incoming){.data = NULL, .length = 0, .id = 0, .seqnum = 0, .source_addr = 0};
char buf[MAX_IP_PACKET_SIZE];
@@ -140,9 +94,6 @@ struct icmp_server_incoming icmp_server_receive(int sock) {
// buf now contains received data starting at the IP header
- // printf("Full packet received:\n");
- // xxd(buf, nr);
-
struct iphdr *hdr = (struct iphdr*)buf;
int hdr_len = hdr->ihl * 4;
uint32_t saddr = hdr->saddr;
@@ -150,20 +101,13 @@ struct icmp_server_incoming icmp_server_receive(int sock) {
struct icmp_echo *msg = (struct icmp_echo*)(buf + hdr_len);
int msg_len = nr - hdr_len;
int payloadlen = msg_len - offsetof(struct icmp_echo, payload);
- // printf("Received: type %u code %u id %hu seqnum %hu payload:\n",
- // (unsigned)msg->type, (unsigned)msg->code, msg->id, msg->seqnum);
- // xxd(msg->payload, payloadlen);
-
- if (msg->type != ICMP_ECHO && msg->type != ICMP_ECHOREPLY) {
- // printf("Not an ICMP_ECHO or ICMP_ECHOREPLY, ignoring\n");
- continue;
- } else {
+
+ if (msg->type == ICMP_ECHO) {
memcpy(buffer, msg->payload, payloadlen);
- return (struct icmp_server_incoming){
+ return (struct icmp_incoming){
.data = buffer,
.length = payloadlen,
- .type = msg->type,
.id = ntohs(msg->id),
.seqnum = ntohs(msg->seqnum),
.source_addr = saddr
@@ -172,19 +116,64 @@ struct icmp_server_incoming icmp_server_receive(int sock) {
}
}
-int icmp_server_send_reply(
+struct icmp_incoming icmp_client_receive(int sock) {
+ static uint8_t buffer[ICMP_MAX_PAYLOAD_LENGTH];
+
+ struct icmp_incoming errret =
+ (struct icmp_incoming){.data = NULL, .length = 0, .id = 0, .seqnum = 0, .source_addr = 0};
+
+ struct msghdr replyhdr;
+ memset(&replyhdr, 0, sizeof replyhdr);
+
+ struct icmp_echo msg;
+
+ struct iovec iov1;
+ memset(&iov1, 0, sizeof iov1);
+ iov1.iov_base = &msg;
+ iov1.iov_len = sizeof msg;
+
+ struct sockaddr_in addr;
+
+ replyhdr.msg_name = &addr;
+ replyhdr.msg_namelen = sizeof addr;
+ replyhdr.msg_iov = &iov1;
+ replyhdr.msg_iovlen = 1;
+
+ ssize_t nr = recvmsg(sock, &replyhdr, 0);
+ if (nr < 0) {
+ return errret;
+ }
+
+ size_t payloadlen = nr - ICMP_PAYLOAD_OFFSET;
+ assert(payloadlen <= MAX_DATAGRAM_SIZE);
+
+ memcpy(buffer, msg.payload, payloadlen);
+
+ return (struct icmp_incoming){
+ .data = buffer,
+ .length = payloadlen,
+ .id = ntohs(msg.id),
+ .seqnum = ntohs(msg.seqnum),
+ .source_addr = addr.sin_addr.s_addr
+ };
+}
+
+static int icmp_server_send(
int sock, uint32_t addr_u32,
int id, int seqnum,
- const void *data_, size_t length) {
+ const void *data_, size_t length,
+ int type) {
const uint8_t *data = (const uint8_t*)data_;
+ assert(length <= ICMP_MAX_PAYLOAD_LENGTH);
+
struct sockaddr_in addr;
make_sockaddr_u32(&addr, addr_u32);
struct icmp_echo msg;
memset(&msg, 0, sizeof msg);
- msg.type = ICMP_ECHOREPLY;
+ msg.type = type;
msg.code = 0;
msg.id = htons(id);
msg.seqnum = htons(seqnum);
@@ -201,3 +190,48 @@ int icmp_server_send_reply(
return 0;
}
+
+int icmp_server_send_reply(
+ int sock, uint32_t addr_u32,
+ int id, int seqnum,
+ const void *data, size_t length) {
+
+ return icmp_server_send(sock, addr_u32, id, seqnum, data, length, ICMP_ECHOREPLY);
+}
+
+int icmp_server_send_echo(
+ int sock, uint32_t addr_u32,
+ int id, int seqnum,
+ const void *data, size_t length) {
+
+ return icmp_server_send(sock, addr_u32, id, seqnum, data, length, ICMP_ECHO);
+}
+
+int icmp_client_send(
+ int sock, uint32_t addr_u32,
+ int seqnum,
+ const void *data_, size_t length) {
+
+ const uint8_t *data = (const uint8_t*)data_;
+
+ assert(length <= ICMP_MAX_PAYLOAD_LENGTH);
+
+ struct sockaddr_in addr;
+ make_sockaddr_u32(&addr, addr_u32);
+
+ struct icmp_echo msg;
+ memset(&msg, 0, sizeof msg);
+ msg.type = ICMP_ECHO;
+ msg.code = 0;
+ msg.id = 0; // overwritten by kernel
+ msg.seqnum = htons(seqnum);
+
+ if (data == NULL) assert(length == 0);
+ else memcpy(msg.payload, data, length);
+
+ if (sendto(sock, &msg, ICMP_PAYLOAD_OFFSET + length, 0, (struct sockaddr*)&addr, sizeof addr) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/icmp.h b/icmp.h
index 4cccb95..eed1714 100644
--- a/icmp.h
+++ b/icmp.h
@@ -22,3 +22,12 @@ struct __attribute__((packed)) icmp_echo {
#define ICMP_MAX_PAYLOAD_LENGTH (MAX_DATAGRAM_SIZE - ICMP_PAYLOAD_OFFSET)
#define ICMP_SAFE_PAYLOAD_LENGTH (MIN_MTU - IP_HEADER_SIZE - ICMP_PAYLOAD_OFFSET)
+
+
+struct icmp_incoming {
+ const uint8_t *data; // points to internal buffer
+ size_t length; // length of 'data'
+
+ int id, seqnum;
+ uint32_t source_addr;
+};
diff --git a/icmp_client.h b/icmp_client.h
index 78cfe7a..3474f5d 100644
--- a/icmp_client.h
+++ b/icmp_client.h
@@ -3,21 +3,24 @@
#include "icmp.h"
-struct icmp_client_incoming {
- const uint8_t *data; // points to internal buffer
- size_t length; // length of 'data'
-
- int id, seqnum;
-};
-
// Returns -1 on error with errno.
int icmp_client_open_socket(void);
+// Returns {.data=NULL} on error with errno.
+// Receives only ECHOREPLY.
+struct icmp_incoming icmp_client_receive(int sock);
+
+// Only actual IPv4 addresses allowed. Sends data in 'data' with length 'length'.
+int icmp_client_send(
+ int sock, uint32_t addr,
+ int seqnum,
+ const void *data, size_t length);
+
// Only actual IPv4 addresses allowed. Sends data in 'data' with length 'length', and
// returns pointer to internal buffer with reply data. Buffer is invalidated on next
// call to the function.
// Returns {.data=NULL} on error with errno.
-struct icmp_client_incoming icmp_client_communicate(
- int sock, const char *ip_address,
- int id, int seqnum,
+struct icmp_incoming icmp_client_communicate(
+ int sock, uint32_t addr,
+ int seqnum,
const void *data, size_t length);
diff --git a/icmp_server.h b/icmp_server.h
index fbf4158..f1f4e9f 100644
--- a/icmp_server.h
+++ b/icmp_server.h
@@ -2,28 +2,13 @@
#include "icmp.h"
-#ifndef ICMP_ECHO
-#define ICMP_ECHO 8
-#endif
-#ifndef ICMP_ECHOREPLY
-#define ICMP_ECHOREPLY 0
-#endif
-
-
-struct icmp_server_incoming {
- const uint8_t *data; // points to internal buffer
- size_t length; // length of 'data'
-
- int type; // ICMP_ECHO or ICMP_ECHOREPLY
- int id, seqnum;
- uint32_t source_addr;
-};
// Returns -1 on error with errno.
int icmp_server_open_socket(void);
// Returns {.data=NULL} on error with errno.
-struct icmp_server_incoming icmp_server_receive(int sock);
+// Receives only ECHO.
+struct icmp_incoming icmp_server_receive(int sock);
// Returns -1 on error with errno.
int icmp_server_send_reply(
diff --git a/icmpd.c b/icmpd.c
new file mode 100644
index 0000000..e3127c7
--- /dev/null
+++ b/icmpd.c
@@ -0,0 +1,502 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/select.h>
+#include "icmpd.h"
+#include "util.h"
+#include "icmp_server.h"
+#include "icmp_client.h"
+
+
+struct icmpd {
+ struct mt_mutex mut; // for this struct
+
+ bool isserver; // constant
+
+ // IPv4 address of other party
+ uint32_t other_addr; // constant
+
+ bool outstanding; // server: whether an echo request hasn't been matched yet
+
+ // id for messages, -1 if not set
+ int id; // constant
+
+ // Client: seqnum can change before every send
+ // Server: seqnum is the sequence number of the last-received ECHO
+ // value is -1 if not set
+ int seqnum;
+};
+
+// Global state
+bool thread_running = false;
+struct mt_mutex thread_mutex; // protecting these global values
+struct mt_thread thread;
+int thread_in, thread_out;
+int host_in, host_out;
+
+
+// Arguments to messages are listed in comments.
+enum {
+ MSG_THREAD_UP, // -
+ MSG_NEWCONN, // struct icmpd*
+ MSG_ENDCONN, // struct icmpd*; free() done by thread
+ MSG_PEEK, // struct icmpd*
+ MSG_PEEK_ANS, // uint8_t (bool)
+ MSG_RECV, // struct icmpd*
+ MSG_RECV_ANS, // struct icmpd_received
+ MSG_SEND, // struct msg_form_send
+};
+
+struct msg_header {
+ int type;
+ size_t size; // size in bytes of argument
+};
+
+struct msg_in {
+ struct msg_header hdr;
+ void *data; // should be free()'d
+};
+
+struct msg_form_send {
+ struct icmpd *d;
+ void *data; // to be free()'d by thread when sent
+ size_t length;
+};
+
+
+static struct icmpd* find_conn(int id, uint32_t addr, struct icmpd **conns, size_t conns_len) {
+ struct icmpd *ret = NULL;
+ for (size_t i = 0; i < conns_len; i++) {
+ struct icmpd *d = conns[i];
+ if ((d->id == -1 || d->id == id) &&
+ (d->other_addr == 0 || d->other_addr == addr)) {
+ if (ret == NULL || (ret->other_addr == 0 && d->other_addr != 0)) {
+ ret = d;
+ } else {
+ fprintf(stderr, "icmpd thread: warning: multiple connections match id=%d addr=%x\n",
+ id, addr);
+ break;
+ }
+ }
+ }
+ return ret;
+}
+
+static void send_message(int sock, int type, const void *data, size_t size) {
+ struct msg_header head = {type, size};
+
+ assert(writeall(sock, &head, sizeof head) == sizeof head);
+ assert(writeall(sock, data, size) == (ssize_t)size);
+}
+
+// On error, {.type=-1}, errno is set
+static struct msg_in recv_message(int sock) {
+ struct msg_in msg;
+
+ int ret = readall(sock, &msg.hdr, sizeof msg.hdr);
+ if (ret < 0) return (struct msg_in){.hdr.type = -1, .hdr.size = 0, .data = NULL};
+ assert(ret == sizeof msg.hdr);
+
+ msg.data = malloc(msg.hdr.size);
+ assert(readall(sock, msg.data, msg.hdr.size) == (ssize_t)msg.hdr.size);
+
+ return msg;
+}
+
+static void client_increment_seqnum(struct icmpd *d) {
+ d->seqnum = (d->seqnum + 1) & 0xffff;
+}
+
+static void* thread_entry(void *arg) {
+ (void)arg;
+
+ send_message(thread_out, MSG_THREAD_UP, NULL, 0);
+
+ struct recvqu_item {
+ struct icmpd *d;
+ struct icmpd_received msg;
+ };
+
+ struct sendqu_item {
+ struct icmpd *d;
+ void *data;
+ size_t length;
+ };
+
+ size_t conns_cap = 8, conns_len = 0;
+ struct icmpd **conns = malloc(conns_cap * sizeof(struct icmpd*));
+
+ int sock_server = -1, sock_client = -1;
+
+ size_t recvqu_cap = 8, recvqu_len = 0;
+ struct recvqu_item *recvqu = malloc(recvqu_cap * sizeof(struct recvqu_item));
+
+ // Server messages submitted for transmission while no non-ponged client
+ // ping is available.
+ size_t sendqu_cap = 8, sendqu_len = 0;
+ struct sendqu_item *sendqu = malloc(sendqu_cap * sizeof(struct sendqu_item));
+
+ while (true) {
+ fd_set inset;
+ FD_ZERO(&inset);
+ FD_SET(thread_in, &inset);
+ if (sock_server >= 0) FD_SET(sock_server, &inset);
+ if (sock_client >= 0) FD_SET(sock_client, &inset);
+
+ int nfds = thread_in;
+ if (sock_server > nfds) nfds = sock_server;
+ if (sock_client > nfds) nfds = sock_client;
+
+ int ret = select(nfds + 1, &inset, NULL, NULL, NULL);
+ if (ret < 0) {
+ if (errno == EINTR) continue;
+ perror("select");
+ assert(false);
+ }
+ assert(ret > 0);
+
+ if (FD_ISSET(thread_in, &inset)) {
+ struct msg_in msg = recv_message(thread_in);
+ if (msg.hdr.type == -1) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK) continue;
+ perror("recv_message");
+ assert(false);
+ }
+
+ switch (msg.hdr.type) {
+ case MSG_NEWCONN: {
+ struct icmpd *d = *(struct icmpd**)msg.data;
+ free(msg.data);
+ if (conns_len == conns_cap) {
+ conns_cap *= 2;
+ conns = realloc(conns, conns_cap * sizeof(struct icmpd*));
+ }
+ conns[conns_len++] = d;
+
+ if (d->isserver) {
+ if (sock_server < 0) {
+ sock_server = icmp_server_open_socket();
+ if (sock_server < 0) {
+ perror("icmp_server_open_socket");
+ assert(false);
+ }
+ }
+ } else {
+ if (sock_client < 0) {
+ sock_client = icmp_client_open_socket();
+ if (sock_client < 0) {
+ perror("icmp_client_open_socket");
+ assert(false);
+ }
+ }
+ }
+ break;
+ }
+
+ case MSG_ENDCONN: {
+ struct icmpd *d = *(struct icmpd**)msg.data;
+ free(msg.data);
+
+ bool found = false;
+ for (size_t i = 0; i < conns_len; i++) {
+ if (conns[i] == d) {
+ memmove(conns + i, conns + i + 1, conns_len - i - 1);
+ conns_len--;
+ found = true;
+ break;
+ }
+ }
+ assert(found);
+
+ mt_mutex_destroy(&d->mut);
+ free(d);
+ break;
+ }
+
+ case MSG_PEEK: {
+ struct icmpd *d = *(struct icmpd**)msg.data;
+ free(msg.data);
+
+ uint8_t ret = 0;
+ for (size_t i = 0; i < recvqu_len; i++) {
+ if (recvqu[i].d == d) {
+ ret = 1;
+ break;
+ }
+ }
+
+ send_message(thread_out, MSG_PEEK_ANS, &ret, 1);
+ break;
+ }
+
+ case MSG_RECV: {
+ struct icmpd *d = *(struct icmpd**)msg.data;
+ free(msg.data);
+
+ ssize_t index = -1;
+ for (size_t i = 0; i < recvqu_len; i++) {
+ if (recvqu[i].d == d) {
+ index = i;
+ break;
+ }
+ }
+
+ assert(index != -1); // TODO: make host wait for something
+
+ send_message(thread_out, MSG_RECV_ANS,
+ &recvqu[index].msg, sizeof recvqu[index].msg);
+
+ memcpy(recvqu + index, recvqu + index + 1,
+ (recvqu_len - index - 1) * sizeof recvqu[0]);
+
+ recvqu_len--;
+ break;
+ }
+
+ case MSG_SEND: {
+ struct msg_form_send form = *(struct msg_form_send*)msg.data;
+ free(msg.data);
+
+ struct icmpd *d = form.d;
+
+ if (d->isserver) {
+ mt_mutex_lock(&d->mut);
+ bool outstanding = d->outstanding;
+ int id = d->id, seqnum = d->seqnum;
+ mt_mutex_unlock(&d->mut);
+
+ if (outstanding) {
+ int ret = icmp_server_send_reply(
+ sock_server, d->other_addr, id, seqnum,
+ form.data, form.length);
+ if (ret < 0) {
+ perror("icmp_server_send_reply");
+ }
+ } else {
+ if (sendqu_len == sendqu_cap) {
+ sendqu_cap *= 2;
+ sendqu = realloc(sendqu, sendqu_cap * sizeof sendqu[0]);
+ }
+
+ sendqu[sendqu_len].d = d;
+ sendqu[sendqu_len].data = form.data;
+ sendqu[sendqu_len].length = form.length;
+ sendqu_len++;
+ }
+ } else {
+ mt_mutex_lock(&d->mut);
+ client_increment_seqnum(d);
+ int seqnum = d->seqnum;
+ mt_mutex_unlock(&d->mut);
+
+ int ret = icmp_client_send(
+ sock_client, d->other_addr, seqnum,
+ form.data, form.length);
+ if (ret < 0) {
+ perror("icmp_client_send");
+ }
+ }
+
+ break;
+ }
+ }
+ }
+
+ if (FD_ISSET(sock_server, &inset)) {
+ struct icmp_incoming msg = icmp_server_receive(sock_server);
+ struct icmpd *d = find_conn(msg.id, msg.source_addr, conns, conns_len);
+
+ if (d == NULL) {
+ fprintf(stderr, "icmpd thread: ping received with unknown id=%d addr=%x\n",
+ msg.id, msg.source_addr);
+ int ret = icmp_server_send_reply(
+ sock_server, msg.source_addr, msg.id, msg.seqnum,
+ msg.data, msg.length);
+ if (ret < 0) {
+ perror("icmpd thread: unknown ping reply: icmp_server_send_reply");
+ }
+ } else {
+ if (msg.length == 0) {
+ fprintf(stderr, "server recv: empty\n");
+ } else {
+ if (recvqu_len == recvqu_cap) {
+ recvqu_cap *= 2;
+ recvqu = realloc(recvqu, recvqu_cap * sizeof(struct recvqu_item));
+ }
+
+ recvqu[recvqu_len].d = d;
+ recvqu[recvqu_len].msg.data = malloc(msg.length);
+ memcpy(recvqu[recvqu_len].msg.data, msg.data, msg.length);
+ recvqu[recvqu_len].msg.length = msg.length;
+ recvqu[recvqu_len].msg.source_addr = msg.source_addr;
+ recvqu[recvqu_len].msg.id = msg.id;
+ recvqu[recvqu_len].msg.seqnum = msg.seqnum;
+ recvqu_len++;
+
+ fprintf(stderr, "server recv: recvqu_len = %zu\n", recvqu_len);
+ }
+
+ ssize_t index = -1;
+ for (size_t i = 0; i < sendqu_len; i++) {
+ if (sendqu[i].d == d) {
+ index = i;
+ break;
+ }
+ }
+
+ if (index != -1) {
+ int ret = icmp_server_send_reply(
+ sock_server, d->other_addr, d->id, d->seqnum,
+ sendqu[index].data, sendqu[index].length);
+ if (ret < 0) {
+ perror("icmp_server_send_reply");
+ }
+
+ memmove(sendqu + index, sendqu + index + 1,
+ (sendqu_len - index - 1) * sizeof sendqu[0]);
+ sendqu_len--;
+ } else {
+ mt_mutex_lock(&d->mut);
+ d->outstanding = true;
+ d->seqnum = msg.seqnum;
+ mt_mutex_unlock(&d->mut);
+ }
+ }
+ }
+
+ if (FD_ISSET(sock_client, &inset)) {
+ struct icmp_incoming msg = icmp_client_receive(sock_client);
+ struct icmpd *d = find_conn(msg.id, msg.source_addr, conns, conns_len);
+
+ if (d == NULL) {
+ fprintf(stderr, "icmpd thread: pong received with unknown id=%d addr=%x\n",
+ msg.id, msg.source_addr);
+ } else {
+ if (recvqu_len == recvqu_cap) {
+ recvqu_cap *= 2;
+ recvqu = realloc(recvqu, recvqu_cap * sizeof(struct recvqu_item));
+ }
+
+ recvqu[recvqu_len].d = d;
+ recvqu[recvqu_len].msg.data = malloc(msg.length);
+ memcpy(recvqu[recvqu_len].msg.data, msg.data, msg.length);
+ recvqu[recvqu_len].msg.length = msg.length;
+ recvqu[recvqu_len].msg.source_addr = msg.source_addr;
+ recvqu[recvqu_len].msg.id = msg.id;
+ recvqu[recvqu_len].msg.seqnum = msg.seqnum;
+ recvqu_len++;
+
+ fprintf(stderr, "client recv: recvqu_len = %zu\n", recvqu_len);
+
+ mt_mutex_lock(&d->mut);
+ client_increment_seqnum(d);
+ int seqnum = d->seqnum;
+ mt_mutex_unlock(&d->mut);
+
+ int ret = icmp_client_send(sock_client, d->other_addr, seqnum, NULL, 0);
+ if (ret < 0) {
+ perror("icmp_client_send");
+ }
+ }
+ }
+ }
+
+ return NULL;
+}
+
+static void spawn_icmpd_thread(void) {
+ int pp[2];
+
+ assert(pipe(pp) == 0);
+ thread_out = pp[1];
+ host_in = pp[0];
+
+ assert(pipe(pp) == 0);
+ host_out = pp[1];
+ thread_in = pp[0];
+
+ mt_mutex_init(&thread_mutex);
+
+ mt_thread_create(&thread, thread_entry, NULL);
+
+ struct msg_in msg = recv_message(host_in);
+ assert(msg.hdr.type == MSG_THREAD_UP);
+ free(msg.data);
+}
+
+static struct icmpd* icmpd_create_base(int id, bool isserver, uint32_t other_addr) {
+ if (!thread_running) {
+ spawn_icmpd_thread();
+ thread_running = true;
+ }
+
+ struct icmpd *d = malloc(sizeof(struct icmpd));
+ mt_mutex_init(&d->mut);
+ d->id = id;
+ d->seqnum = -1;
+ d->isserver = isserver;
+ d->other_addr = other_addr;
+ d->outstanding = false;
+
+ send_message(host_out, MSG_NEWCONN, &d, sizeof d);
+
+ return d;
+}
+
+struct icmpd* icmpd_create_server(int id, uint32_t client_addr) {
+ return icmpd_create_base(id, true, client_addr);
+}
+
+struct icmpd* icmpd_create_client(uint32_t server_addr) {
+ assert(server_addr != 0);
+ return icmpd_create_base(-1, false, server_addr);
+}
+
+void icmpd_destroy(struct icmpd *d) {
+ send_message(host_out, MSG_ENDCONN, &d, sizeof d);
+ // free() is done by thread
+}
+
+void icmpd_server_set_outstanding(struct icmpd *d, int seqnum) {
+ assert(d->isserver);
+ mt_mutex_lock(&d->mut);
+ d->outstanding = true;
+ d->seqnum = seqnum;
+ mt_mutex_unlock(&d->mut);
+}
+
+bool icmpd_peek(struct icmpd *d) {
+ send_message(host_out, MSG_PEEK, &d, sizeof d);
+ struct msg_in msg = recv_message(host_in);
+ assert(msg.hdr.type == MSG_PEEK_ANS);
+
+ bool ret = ((uint8_t*)msg.data)[0];
+ free(msg.data);
+ return ret;
+}
+
+struct icmpd_received icmpd_recv(struct icmpd *d) {
+ send_message(host_out, MSG_RECV, &d, sizeof d);
+ struct msg_in msg = recv_message(host_in);
+ assert(msg.hdr.type == MSG_RECV_ANS);
+
+ struct icmpd_received r;
+ assert(msg.hdr.size == sizeof r);
+ memcpy(&r, msg.data, sizeof r);
+ return r;
+}
+
+void icmpd_send(struct icmpd *d, const void *data, size_t length) {
+ struct msg_form_send form;
+ form.d = d;
+ form.data = malloc(length);
+ memcpy(form.data, data, length);
+ form.length = length;
+
+ send_message(host_out, MSG_SEND, &form, sizeof form);
+}
diff --git a/icmpd.h b/icmpd.h
new file mode 100644
index 0000000..7a87ec6
--- /dev/null
+++ b/icmpd.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "mt.h"
+
+
+struct icmpd_received {
+ uint8_t *data; // points to malloc'd buffer; should be freed by recipient
+ size_t length; // length of 'data'
+
+ uint32_t source_addr;
+ int id, seqnum;
+};
+
+
+struct icmpd;
+
+// Pass 0 as client_addr to listen for messages from any IP (this channel will then only receive unassigned messages)
+// Pass -1 as id to listen for messages with any id
+struct icmpd* icmpd_create_server(int id, uint32_t client_addr);
+
+struct icmpd* icmpd_create_client(uint32_t server_addr);
+
+void icmpd_server_set_outstanding(struct icmpd *d, int seqnum);
+
+bool icmpd_peek(struct icmpd *d);
+struct icmpd_received icmpd_recv(struct icmpd *d);
+void icmpd_send(struct icmpd *d, const void *data, size_t length);
+
+void icmpd_destroy(struct icmpd *d);
diff --git a/mt.c b/mt.c
new file mode 100644
index 0000000..e5b241e
--- /dev/null
+++ b/mt.c
@@ -0,0 +1,29 @@
+#include <assert.h>
+#include "mt.h"
+
+
+void mt_mutex_init(struct mt_mutex *mut) {
+ assert(pthread_mutex_init(&mut->m, NULL) == 0);
+}
+
+void mt_mutex_destroy(struct mt_mutex *mut) {
+ assert(pthread_mutex_destroy(&mut->m) == 0);
+}
+
+void mt_mutex_lock(struct mt_mutex *mut) {
+ assert(pthread_mutex_lock(&mut->m) == 0);
+}
+
+void mt_mutex_unlock(struct mt_mutex *mut) {
+ assert(pthread_mutex_unlock(&mut->m) == 0);
+}
+
+void mt_thread_create(struct mt_thread *th, void* (*callback)(void*), void *arg) {
+ assert(pthread_create(&th->t, NULL, callback, arg) == 0);
+}
+
+void* mt_thread_join(struct mt_thread *th) {
+ void *ret;
+ assert(pthread_join(th->t, &ret));
+ return ret;
+}
diff --git a/mt.h b/mt.h
new file mode 100644
index 0000000..57afd5c
--- /dev/null
+++ b/mt.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <pthread.h>
+
+
+// The structs in this file should be considered opaque.
+
+
+struct mt_mutex {
+ pthread_mutex_t m;
+};
+
+void mt_mutex_init(struct mt_mutex *mut);
+void mt_mutex_destroy(struct mt_mutex *mut);
+void mt_mutex_lock(struct mt_mutex *mut);
+void mt_mutex_unlock(struct mt_mutex *mut);
+
+struct mt_thread {
+ pthread_t t;
+};
+
+void mt_thread_create(struct mt_thread *th, void* (*callback)(void*), void *arg);
+void* mt_thread_join(struct mt_thread *th);
diff --git a/run_server.sh b/run_server.sh
index 42b6aef..e6beee9 100755
--- a/run_server.sh
+++ b/run_server.sh
@@ -6,4 +6,4 @@ fi
echo 1 >/proc/sys/net/ipv4/icmp_echo_ignore_all
trap "echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_all" EXIT
-./server
+./serverd
diff --git a/server.c b/server.c
index 9b16173..df51032 100644
--- a/server.c
+++ b/server.c
@@ -1,6 +1,7 @@
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
+#include <ctype.h>
#include <unistd.h>
#include "icmp_server.h"
#include "util.h"
@@ -14,21 +15,22 @@ int main(void) {
}
while (true) {
- struct icmp_server_incoming msg = icmp_server_receive(sock);
+ struct icmp_incoming msg = icmp_server_receive(sock);
if (msg.data == NULL) {
perror("icmp_server_communicate");
return 1;
}
- printf("Received: type %d id %d seqnum %d data:\n", msg.type, msg.id, msg.seqnum);
+ printf("Received: id %d seqnum %d data:\n", msg.id, msg.seqnum);
xxd(msg.data, msg.length);
- if (msg.type != ICMP_ECHO) {
- printf("Not an ICMP_ECHO, ignoring\n");
- continue;
+ char data[msg.length + 1];
+ for (size_t i = 0; i < msg.length; i++) {
+ data[i] = toupper(msg.data[i]);
}
+ data[msg.length] = '!';
- if (icmp_server_send_reply(sock, msg.source_addr, msg.id, msg.seqnum, "dank je wel", 11) < 0) {
+ if (icmp_server_send_reply(sock, msg.source_addr, msg.id, msg.seqnum, data, msg.length + 1) < 0) {
perror("icmp_server_send_reply");
}
}
diff --git a/serverd.c b/serverd.c
new file mode 100644
index 0000000..6f21530
--- /dev/null
+++ b/serverd.c
@@ -0,0 +1,73 @@
+#define _GNU_SOURCE // usleep, getline
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/select.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
+#include "icmpd.h"
+#include "util.h"
+
+
+int main(void) {
+ struct icmpd *server = icmpd_create_server(-1, 0);
+ struct icmpd *conn = NULL;
+
+ while (true) {
+ // printf("Iter\n");
+
+ if (icmpd_peek(server)) {
+ struct icmpd_received msg = icmpd_recv(server);
+ printf("Server recv: %zu\n", msg.length);
+ xxd(msg.data, msg.length);
+
+ if (conn) {
+ printf("Message received while already connected\n");
+ struct icmpd *d = icmpd_create_server(msg.id, msg.source_addr);
+ icmpd_server_set_outstanding(d, msg.seqnum);
+ icmpd_send(d, msg.data, msg.length);
+ icmpd_destroy(d);
+ } else {
+ conn = icmpd_create_server(msg.id, msg.source_addr);
+ icmpd_server_set_outstanding(conn, msg.seqnum);
+
+ // icmpd_send(conn, "dankje", 6);
+ // icmpd_destroy(conn);
+ }
+
+ free(msg.data);
+ }
+
+ if (icmpd_peek(conn)) {
+ struct icmpd_received msg = icmpd_recv(conn);
+ printf("Connection recv: %zu\n", msg.length);
+ xxd(msg.data, msg.length);
+ free(msg.data);
+ }
+
+ fd_set inset;
+ FD_ZERO(&inset);
+ FD_SET(0, &inset);
+ struct timeval tv;
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+ int ret = select(1, &inset, NULL, NULL, &tv);
+ if (ret < 0) {
+ if (errno == EINTR) continue;
+ perror("select");
+ return 1;
+ }
+ if (ret == 0) continue; // timeout
+ if (FD_ISSET(0, &inset)) {
+ char *line = NULL;
+ size_t linelen = 0;
+ ssize_t nr = getline(&line, &linelen, stdin);
+ assert(nr >= 0);
+ if (nr > 0) nr--;
+ icmpd_send(conn, line, nr);
+ free(line);
+ }
+ }
+}
diff --git a/util.c b/util.c
index be7083c..d4bd0ec 100644
--- a/util.c
+++ b/util.c
@@ -1,8 +1,17 @@
#include <stdio.h>
+#include <stdlib.h>
#include <ctype.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
#include "util.h"
+int uniqid(void) {
+ static int i = 0;
+ return i++;
+}
+
void xxd(const void *buf_, size_t length) {
unsigned char *buf = (unsigned char*)buf_;
@@ -28,3 +37,31 @@ void xxd(const void *buf_, size_t length) {
cursor += 16;
}
}
+
+ssize_t readall(int fd, void *data, size_t length) {
+ size_t cursor = 0;
+ while (cursor < length) {
+ ssize_t nr = read(fd, data + cursor, length - cursor);
+ if (nr < 0) {
+ if (errno == EINTR) continue;
+ return -1;
+ }
+ assert(nr > 0);
+ cursor += nr;
+ }
+ return length;
+}
+
+ssize_t writeall(int fd, const void *data, size_t length) {
+ size_t cursor = 0;
+ while (cursor < length) {
+ ssize_t nw = write(fd, data + cursor, length - cursor);
+ if (nw < 0) {
+ if (errno == EINTR) continue;
+ return -1;
+ }
+ assert(nw > 0);
+ cursor += nw;
+ }
+ return length;
+}
diff --git a/util.h b/util.h
index ea48028..4b2b21c 100644
--- a/util.h
+++ b/util.h
@@ -1,6 +1,10 @@
#pragma once
#include <stdlib.h>
+#include <unistd.h>
+int uniqid(void);
void xxd(const void *buf, size_t length);
+ssize_t readall(int fd, void *data, size_t length);
+ssize_t writeall(int fd, const void *data, size_t length);
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-12-05 03:10:49 +0100