commit da51d3ef3df48260243428732fac196dcfc7c755
Author: Philippe PITTOLI <p.pittoli@unistra.fr>
Date:   Thu May 26 18:27:59 2016 +0200

    core : lib com ++

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..5311fd5
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,29 @@
+CC=gcc
+CFLAGS=-Wall -g
+LDFLAGS=
+CFILES=$(wildcard *.c) # CFILES => recompiles everything on a C file change
+EXEC=$(basename $(wildcard *.c))
+SOURCES=$(wildcard lib/*.c)
+OBJECTS=$(SOURCES:.c=.o)
+TESTS=$(addsuffix .test, $(EXEC))
+
+all: $(SOURCES) $(EXEC)
+
+$(EXEC): $(OBJECTS) $(CFILES)
+	$(CC) $(CFLAGS) $(LDFLAGS) $(OBJECTS) $@.c -o $@
+
+.c.o:
+	$(CC) -c $(CFLAGS) $< -o $@
+
+clean:
+	-rm $(OBJECTS)
+
+mrproper: clean
+	rm $(EXEC)
+
+# to test a binary "prog" : make prog.test
+
+$(TESTS):
+	valgrind --leak-check=full -v --track-origins=yes ./$(basename $@)
+
+test: all $(TESTS)
diff --git a/README.markdown b/README.markdown
new file mode 100644
index 0000000..3b671af
--- /dev/null
+++ b/README.markdown
@@ -0,0 +1,41 @@
+# connection init (draft)
+
+## what the programs should do and how they interact
+
+ * service : application providing a feature to others (windows, audio, …)
+ * program : specific application (browser, instant messaging, …)
+
+ * <service> : service name
+ * <index> : process index in the program point of view
+ * <pindex> : process index in the service point of view
+
+ 1. the service creates a pipe, named /tmp/<service>
+ 2. the program creates pipes named /tmp/$pid-<index>-{in,out}
+ 3. the program prints in the pipe /tmp/<service> : $pid-<index> version
+ 4. depending on the configuration and service type, the service will
+  * thread, to spare resources
+  * fork, not to compromise the security
+ 5. the service prints <pindex> in /tmp/$pid-<index>-in
+
+## pure "networking" view (what should go in the pipes)
+
+ 1. the program prints in the pipe /tmp/<service> : $pid-<index> version
+ 2. the service prints <pindex> in /tmp/$pid-<index>-in
+
+# messages format
+
+QUESTION : no CBOR for 1 & 2, or CBOR everywhere ?
+
+## overview
+
+<type> : value
+
+<type> will be a simple byte :
+
+ * <0 - 15>   : control, meta data
+ * <16 - 127> : later use
+ * <128 - 255> : application specific (windowing system, audio system, …)
+
+## CBOR table (draft)
+
+index | semantic
diff --git a/init-connection.c b/init-connection.c
new file mode 100644
index 0000000..bb1868d
--- /dev/null
+++ b/init-connection.c
@@ -0,0 +1,43 @@
+#include "lib/communication.h"
+
+/*
+ * pipes creation and removal test program
+ *
+ * 1. to create the named pipe /tmp/<service>
+ * 2. to create the named pipes in & out
+ * 3. to remove the named pipes in & out
+ * 4. to remove the named pipe /tmp/<service>
+ */
+
+int main(int argc, char * argv[])
+{
+    // service path (/tmp/<service>)
+    char spath[PATH_MAX];
+    service_path (spath, "windows");
+
+    int ret;
+    if ((ret = service_create (spath))) {
+        fprintf(stdout, "error service_create %d\n", ret);
+        exit (1);
+    }
+
+    struct process proc;
+    if ((ret = process_create (&proc, 0))) {
+        fprintf(stdout, "error process_create %d\n", ret);
+        exit (1);
+    }
+
+    /* specific code, talks between applications */
+
+    if ((ret = process_destroy (&proc))) {
+        fprintf(stdout, "error process_destroy %d\n", ret);
+        exit (1);
+    }
+
+    if ((ret = service_close (spath))) {
+        fprintf(stdout, "error service_close %d\n", ret);
+        exit (1);
+    }
+
+    return EXIT_SUCCESS;
+}
diff --git a/lib/communication.c b/lib/communication.c
new file mode 100644
index 0000000..87cf5a3
--- /dev/null
+++ b/lib/communication.c
@@ -0,0 +1,177 @@
+#include "communication.h"
+
+int service_path (char *buf, const char *sname)
+{
+    if (buf == NULL) {
+        return 1;
+    }
+
+    // already done in mkfifo
+    if (strlen(TMPDIR) + strlen(sname) > PATH_MAX) {
+        return 2;
+    }
+
+    bzero (buf, PATH_MAX);
+    strncat (buf, TMPDIR, PATH_MAX);
+    strncat (buf, sname, PATH_MAX);
+
+    return 0;
+}
+
+void process_paths (char *in, char *out, pid_t pid, int index)
+{
+    bzero (in, PATH_MAX);
+    bzero (out, PATH_MAX);
+    snprintf(in , PATH_MAX, "%s/%d-%d-in" , TMPDIR, pid, index);
+    snprintf(out, PATH_MAX, "%s/%d-%d-out", TMPDIR, pid, index);
+}
+
+int service_create (const char *fifopath)
+{
+    int ret;
+    if ((ret = mkfifo (fifopath, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))) {
+        return 1;
+    }
+
+    return 0;
+}
+
+int service_close (const char *fifopath)
+{
+    if (unlink (fifopath)) {
+        return 1;
+    }
+
+    return 0;
+}
+
+void service_get_new_processes (struct process **proc, int *nproc, int sfifo)
+{
+    char buf[BUFSIZ];
+    bzero (buf, BUFSIZ);
+    read (sfifo, buf, BUFSIZ);
+
+    // TODO
+#if 0
+    unsigned long long int val = strtoull(s, NULL, 10);
+
+    char *token, *saveptr;
+    char *str;
+    int i, j;
+
+    // printf("%d fields :: ", f->nbfields);
+    // for( i = 0 ; i < f->nbfields ; i++) {
+    //     printf("%u, ", f->fields[i]);
+    // }
+    // printf("\n");
+
+    for (str = s, i = 1; ; str = NULL, i++) {
+        token = strtok_r(str, delim, &saveptr);
+        if (token == NULL)
+            break;
+
+        // check if we need to print the current token humanized
+        int found = 0;
+
+        for (j = 0 ; j < f->nbfields && found == 0; j++ ) {
+            if( i == f->fields[j] ) {
+                print_token_to_human(token);
+                found = 1;
+            }
+        }
+
+        // print the current token not humanized
+        if (found == 0) {
+            printf("%s ", token);
+        }
+    }
+#endif
+}
+
+void gen_process_structure (struct process *p
+        , pid_t pid, unsigned int index, unsigned int version)
+{
+    p->pid = pid;
+    p->version = version;
+    p->index = index;
+}
+
+
+int process_create (struct process *p, int index)
+{
+    pid_t pid = getpid();
+    char fifopathin[PATH_MAX];
+    char fifopathout[PATH_MAX];
+    process_paths (fifopathin, fifopathout, pid, index);
+
+    // creates the pipes
+    int ret;
+    if ((ret = mkfifo (fifopathin, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))) {
+        return 1;
+    }
+
+    if ((ret = mkfifo (fifopathout, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))) {
+        return 1;
+    }
+
+    // then creates the structure
+    gen_process_structure (p, pid, index, COMMUNICATION_VERSION);
+
+    return 0;
+}
+
+int process_destroy (struct process *p)
+{
+    char fifopathin[PATH_MAX];
+    char fifopathout[PATH_MAX];
+    process_paths (fifopathin, fifopathout, p->pid, p->index);
+
+    if (unlink (fifopathin)) {
+        return 1;
+    }
+
+    if (unlink (fifopathout)) {
+        return 1;
+    }
+
+    return 0;
+}
+
+
+int process_open (struct process *proc)
+{
+    char fifopathin[PATH_MAX];
+    char fifopathout[PATH_MAX];
+    process_paths (fifopathin, fifopathout, proc->pid, proc->index);
+
+    proc->in = open (fifopathin, S_IRUSR);
+    proc->out = open (fifopathout, S_IRUSR);
+
+    return 0;
+}
+
+int process_close (struct process *proc)
+{
+    if (proc->in != 0) {
+        close (proc->in);
+        proc->in = 0;
+    }
+
+    if (proc->out != 0) {
+        close (proc->out);
+        proc->out = 0;
+    }
+
+    return 0;
+}
+
+
+int process_read (struct process *proc, void * buf, size_t * msize)
+{
+    return 0;
+}
+
+int process_write (struct process *proc, void * buf, size_t msize)
+{
+    return 0;
+}
diff --git a/lib/communication.h b/lib/communication.h
new file mode 100644
index 0000000..aec6da6
--- /dev/null
+++ b/lib/communication.h
@@ -0,0 +1,56 @@
+#ifndef __COMMUNICATION_H__
+#define __COMMUNICATION_H__
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <unistd.h> // unlink
+
+#include <sys/types.h> // mkfifo
+#include <sys/stat.h> // mkfifo
+#include <fcntl.h> // open
+
+#define TMPDIR "/tmp/"
+
+#define COMMUNICATION_VERSION 1
+
+// TODO to check the right length for a path
+#define PATH_MAX BUFSIZ
+
+struct process {
+    pid_t pid;
+    unsigned int version;
+    unsigned int index;
+    int in, out;
+};
+
+// TODO create the service process structure
+
+int service_path (char *buf, const char *sname);
+
+void gen_process_structure (struct process *p
+        , pid_t pid, unsigned int index, unsigned int version);
+
+/*
+ * returns
+ *  0 : ok
+ *  1 : no service name
+ *  2 : service name too long
+ *  3 : unable to create fifo
+ */
+int service_create (const char *sname);
+int service_close (const char *sname);
+
+void service_get_new_processes (struct process **, int *nproc, int sfifo);
+
+int process_create (struct process *, int index); // called by the application
+int process_destroy (struct process *); // called by the application
+
+int process_open (struct process *); // called by the service & application
+int process_close (struct process *); // called by the service & application
+
+int process_read (struct process *, void * buf, size_t *);
+int process_write (struct process *, void * buf, size_t);
+
+#endif
diff --git a/service-test.c b/service-test.c
new file mode 100644
index 0000000..dca4865
--- /dev/null
+++ b/service-test.c
@@ -0,0 +1,89 @@
+#include "lib/communication.h"
+
+/*
+ * main loop
+ *
+ * opens the application pipes,
+ * reads then writes the same message,
+ * then closes the pipes
+ */
+
+void main_loop (const char *spath)
+{
+    int ret;
+    int sfifo = open (spath, S_IRUSR); // opens the service named pipe
+
+    struct process *proc;
+    int nproc = 0;
+
+    do {
+        service_get_new_processes (&proc, &nproc, sfifo);
+
+        // for each process : open, read, write, close
+        for (int i = 0 ; i < nproc ; i++) {
+            printf ("new connected process : %d, version %d, index %d\n"
+                    , proc[i].pid, proc[i].version, proc[i].index);
+
+            if ((ret = process_open (&proc[i]))) {
+                fprintf(stdout, "error process_create %d\n", ret);
+                exit (1);
+            }
+
+            // about the message
+            size_t msize;
+            char *buf;
+
+            if ((ret = process_read (&proc[i], &buf, &msize))) {
+                fprintf(stdout, "error process_read %d\n", ret);
+                exit (1);
+            }
+
+            if ((ret = process_write (&proc[i], &buf, msize))) {
+                fprintf(stdout, "error process_read %d\n", ret);
+                exit (1);
+            }
+
+            if ((ret = process_close (&proc[i]))) {
+                fprintf(stdout, "error process_destroy %d\n", ret);
+                exit (1);
+            }
+        }
+    } while (0); // it's a test, we only do it once
+
+    close (sfifo); // closes the service named pipe
+}
+
+/*
+ * service test
+ *
+ * 1. creates the named pipe /tmp/<service>, then listens
+ * 2. opens the named pipes in & out
+ * 3. talks with the (test) program
+ * 4. closes the test program named pipes
+ * 5. removes the named pipe /tmp/<service>
+ */
+
+int main(int argc, char * argv[])
+{
+    // gets the service path, such as /tmp/<service>
+    char spath[PATH_MAX];
+    service_path (spath, "windows");
+
+    // creates the service named pipe, that listens to client applications
+    int ret;
+    if ((ret = service_create (spath))) {
+        fprintf(stdout, "error service_create %d\n", ret);
+        exit (1);
+    }
+
+    // the service will loop until the end of time, a specific message, a signal
+    main_loop (spath);
+
+    // the application will shut down, and remove the service named pipe
+    if ((ret = service_close ("windows"))) {
+        fprintf(stdout, "error service_close %d\n", ret);
+        exit (1);
+    }
+
+    return EXIT_SUCCESS;
+}