basic structure and client process chain done

.clang-format

@@ -0,0 +1,10 @@
+BasedOnStyle: LLVM
+UseTab: Always
+IndentWidth: 4
+TabWidth: 4
+BreakBeforeBraces: Attach
+ColumnLimit: 100
+PenaltyReturnTypeOnItsOwnLine: 1000000
+AlwaysBreakAfterDefinitionReturnType: None
+SeparateDefinitionBlocks: Always
+AlignConsecutiveMacros: Consecutive

.gitignore

@@ -1,6 +1,7 @@
 # ---> C
 # Prerequisites
 *.d
+bin/
 
 # Object files
 *.o

Makefile

@@ -0,0 +1,43 @@
+# Compiler
+CC := /opt/homebrew/opt/llvm/bin/clang
+# Compiler flags
+CFLAGS := -Wall -Wextra -Werror -Ilibs -fsanitize=address
+
+# Directories
+SRCDIR := src
+BINDIR := bin
+LIBDIR := libs
+
+# Source files
+SRCS := $(wildcard $(SRCDIR)/*.c)
+# Object files
+OBJS := $(patsubst $(SRCDIR)/%.c,$(BINDIR)/%.o,$(SRCS))
+
+# Libraries
+LIBS := $(wildcard $(LIBDIR)/*/*.c)
+# Library object files
+LIBOBJS := $(patsubst %.c,%.o,$(LIBS))
+
+# Target executables
+EXECUTABLES := $(patsubst $(SRCDIR)/%,$(BINDIR)/%,$(basename $(wildcard $(SRCDIR)/*/*.c)))
+
+.PHONY: all clean
+
+all: $(EXECUTABLES)
+
+$(BINDIR)/%: $(BINDIR)/%.o $(LIBOBJS)
+	$(CC) $(CFLAGS) $^ -o $@
+
+$(BINDIR)/%.o: $(SRCDIR)/%.c | $(BINDIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(BINDIR):
+	mkdir -p $(BINDIR)
+
+permissions: $(BINDIR)/djumbai_enqueue/djumbai_enqueue
+	chown djumbaiq $(BINDIR)/djumbai_enqueue/djumbai_enqueue
+	chmod u+s $(BINDIR)/djumbai_enqueue/djumbai_enqueue
+
+clean:
+	rm -rf $(BINDIR)
+

README.md

@@ -32,7 +32,7 @@ This structured breakdown elucidates the sequential steps involved in the Unix m
 
 ## Cenas concretas
 
-Mail queue - FIFO em /opt/djumbai/mailqueue e so pode ser acedida por users do grupo djumbai-queue, que contem djumbai-enqueue e djumbai-dequeue
+Mail queue - FIFO em /opt/djumbai/queue/mailqueue e so pode ser acedida por users do grupo djumbai-queue, que contem djumbai-enqueue e djumbai-dequeue
 
 Mailbox pessoal - Diretoria em /opt/djumbai/mailbox/user/$uid, que so pode ser acedida pelo user com UID $uid
 
@@ -40,8 +40,6 @@ Mailbox grupo - Diretoria em /opt/djumbai/mailbox/group/$gid, que so pode ser ac
 
 SentBox pessoal - Diretoria em /opt/djumbai/sentbox/user/$uid, que so pode ser acedida pelo user com UID $uid
 
-SentBox grupo - Diretoria em /opt/djumbai/sentbox/grupo/$gid, que so pode ser acedida pelo grupo com GID $gid
-
 Repositorio de chaves publicas de utilizadores - Diretoria em /opt/djumbai/pub_keys/user/$uid que contem as chaves publicas de cada utilizador. Apenas o proprio user tem acesso de escrita no ficheiro da sua chave publica
 
 Repositorio de chaves publicas de grupos - Diretoria em /opt/djumbai/pub_keys/group/$gid que contem as chaves publicas de cada grupo. Apenas membros do proprio grupo tem acesso de escrita no ficheiro da sua chave publica

libs/communication/communication.c

@@ -0,0 +1,11 @@
+#include "communication.h"
+
+int serialize_message(void *msg,long msg_size, unsigned char *out) {
+	memcpy(out, msg, msg_size);
+	return 0;
+}
+
+int deserialize_message(unsigned char *in,long msg_size, void *msg) {
+	memcpy(msg, in, msg_size);
+	return 0;
+}

libs/communication/communication.h

@@ -0,0 +1,9 @@
+#ifndef COMMUNICATION_H
+#define COMMUNICATION_H
+
+#include <string.h>
+
+int serialize_message(void *msg, long msg_size, unsigned char *out);
+int deserialize_message(unsigned char *in, long msg_size, void *msg);
+
+#endif // !COMMUNICATION_H

libs/protocol/protocol.c

@@ -0,0 +1,13 @@
+#include "protocol.h"
+
+int new_message(message *m, unsigned int sender, unsigned int receiver, char *content) {
+	if (strlen(content) > MAX_CONTENT_SIZE) {
+		return 1;
+	}
+	m->header.version = VERSION;
+	m->header.sender = sender;
+	m->header.receiver = receiver;
+	time(&m->header.timestamp);
+	strncpy(m->content, content, MAX_CONTENT_SIZE);
+	return 0;
+}

libs/protocol/protocol.h

@@ -0,0 +1,34 @@
+#ifndef PROTOCOL_H
+#define PROTOCOL_H
+
+#include <limits.h>
+#include <stdint.h>
+#include <string.h>
+#include <time.h>
+
+#define VERSION			 1
+#define MAX_CONTENT_SIZE (PIPE_BUF - sizeof(struct MessageHeader))
+#define MESSAGE_SIZE sizeof(struct Message)
+
+typedef struct MessageHeader {
+	// The protocol's version
+	unsigned int version;
+	// The sender is a user
+	unsigned int sender;
+	// The receiver is either a user or a group
+	unsigned int receiver;
+	// The message was sent at this timestamp
+	time_t timestamp;
+} message_header;
+
+typedef struct Message {
+	// The message's header
+	message_header header;
+	// The buffer holding the message
+	char content[MAX_CONTENT_SIZE];
+} message;
+
+
+int new_message(message *m, unsigned int sender, unsigned int receiver, char *content);
+
+#endif // !PROTOCOL_H

src/client.c

@@ -1,4 +0,0 @@
-#include <sys/stat.h>
-
-int main(){
-}

src/client/client.c

@@ -0,0 +1,68 @@
+#include "client.h"
+#include <stdio.h>
+
+int send_message(unsigned int sender, unsigned int receiver) {
+	int pipe_to_child[2];
+
+	if (pipe(pipe_to_child) == -1) {
+		perror("pipe");
+		exit(EXIT_FAILURE);
+	}
+
+	pid_t pid = fork();
+	if (pid == -1) {
+		perror("fork");
+		exit(EXIT_FAILURE);
+	}
+
+	if (pid == 0) {				 // Child process
+		close(pipe_to_child[1]); // Close write end of pipe
+
+		// Redirect stdin to read from pipe_to_child
+		dup2(pipe_to_child[0], STDIN_FILENO);
+
+
+		// Execute a command, for example, a simple "cat" command
+		execlp("./bin/djumbai_client_send/djumbai_client_send", "djumbai_client_send", NULL);
+
+		// If execlp fails
+		perror("execlp");
+		close(pipe_to_child[0]);
+		exit(EXIT_FAILURE);
+	} else {					 // Parent process
+		close(pipe_to_child[0]); // Close read end of pipe
+
+		printf("Please enter your message (Max of %ld bytes):\n", MAX_CONTENT_SIZE);
+		char content[MAX_CONTENT_SIZE];
+		fgets(content, MAX_CONTENT_SIZE, stdin);
+
+		message msg;
+		if (new_message(&msg, sender, receiver, content) != 0) {
+			printf("Error when creating new message\n");
+		}
+
+		// Serialize the message
+		unsigned char buffer[sizeof(struct Message)];
+		if (serialize_message(&msg, sizeof(struct Message), buffer) == -1) {
+			fprintf(stderr, "Error: Serialization failed\n");
+			return 1;
+		}
+
+		write(pipe_to_child[1], buffer, sizeof(buffer));
+
+		// Close the write end of the pipe
+		close(pipe_to_child[1]);
+		// Wait for the child process to finish
+		wait(NULL);
+	}
+
+	return 0;
+}
+
+int main() {
+	// TODO: Client parsing to be done
+	unsigned int sender = getuid();
+	unsigned int receiver = 1000;
+	send_message(sender, receiver);
+	return 0;
+}

src/client/client.h

@@ -0,0 +1,12 @@
+#ifndef CLIENT_H
+#define CLIENT_H
+
+#include "../../libs/communication/communication.h"
+#include "../../libs/protocol/protocol.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+int send_message(unsigned int sender, unsigned int receiver);
+#endif // !CLIENT_H

src/djumbai_client_receive/djumbai_client_receive.c

@@ -0,0 +1,3 @@
+int main(){
+
+}

src/djumbai_client_send/djumbai_client_send.c

@@ -0,0 +1,47 @@
+#include "../../libs/protocol/protocol.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main() {
+
+	int pipe_to_child[2];
+
+	if (pipe(pipe_to_child) == -1) {
+		perror("pipe");
+		exit(EXIT_FAILURE);
+	}
+
+	pid_t pid = fork();
+	if (pid == -1) {
+		perror("fork");
+		exit(EXIT_FAILURE);
+	}
+
+	if (pid == 0) {				 // Child process
+		close(pipe_to_child[1]); // Close write end of pipe
+
+		// Redirect stdin to read from pipe_to_child
+		dup2(pipe_to_child[0], STDIN_FILENO);
+
+		execlp("./bin/djumbai_enqueue/djumbai_enqueue", "djumbai_enqueue", NULL);
+
+		// If execlp fails
+		perror("execlp");
+		close(pipe_to_child[0]);
+		exit(EXIT_FAILURE);
+	} else {					 // Parent process
+		close(pipe_to_child[0]); // Close read end of pipe
+
+		unsigned char buffer[sizeof(struct Message)];
+		read(0, buffer, sizeof(struct Message));
+		write(pipe_to_child[1], buffer, sizeof(buffer));
+
+		// Close the write end of the pipe
+		close(pipe_to_child[1]);
+		// Wait for the child process to finish
+		wait(NULL);
+	}
+
+	return 0;
+}

src/djumbai_dequeue/djumbai_dequeue.c

@@ -0,0 +1,8 @@
+#include <unistd.h>
+
+int main(){
+    //Make stdin the FIFO
+    //Read from FIFO
+    //Make stdout the output FIFO
+    //Write to another FIFO
+}

src/djumbai_dequeue/djumbai_dequeue.h

@@ -0,0 +1,8 @@
+#include <unistd.h>
+
+int main(){
+    //Make stdin the FIFO
+    //Read from FIFO
+    //Make stdout the output FIFO
+    //Write to another FIFO
+}

src/djumbai_enqueue/djumbai_enqueue.c

@@ -0,0 +1,30 @@
+#include "djumbai_enqueue.h"
+
+int main() {
+    //Change the root of the djumbai_enqueue process so it doesn't have access to anything else.
+    chroot("/opt/djumbai/queue/");
+	const char *message_queue_path =
+		"mailqueue"; // Replace this with the path to your FIFO
+
+	// Open the FIFO for writing
+	int queue_fd;
+	queue_fd = open(message_queue_path, O_WRONLY);
+	if (queue_fd == -1) {
+		if (errno == ENOENT) {
+			// FIFO does not exist
+			printf("FIFO '%s' does not exist. Exiting...\n", message_queue_path);
+			return 1;
+		} else {
+			perror("open");
+			return 1;
+		}
+	}
+
+	// Read message from stdin
+	unsigned char buffer[MESSAGE_SIZE];
+	read(0, buffer, MESSAGE_SIZE);
+
+	// Write message to message queue
+	write(queue_fd, buffer, MESSAGE_SIZE);
+    close(queue_fd);
+}

src/djumbai_enqueue/djumbai_enqueue.h

@@ -0,0 +1,12 @@
+#ifndef DJUMBAI_ENQUEUE_H
+#define DJUMBAI_ENQUEUE_H
+
+#include "../../libs/protocol/protocol.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main();
+
+#endif // !DJUMBAI_ENQUEUE_H

src/djumbai_send/djumbai_send.c

@@ -0,0 +1,3 @@
+int main(){
+
+}