From 7ab92ebb3424e904ee78862683eb65fb60d878f6 Mon Sep 17 00:00:00 2001
From: Niklas Halle <niklas@niklashalle.net>
Date: Mon, 8 Jun 2020 17:30:18 +0200
Subject: multiple clients

---
 03_exercise/srv/server.c | 62 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 15 deletions(-)

(limited to '03_exercise/srv/server.c')

diff --git a/03_exercise/srv/server.c b/03_exercise/srv/server.c
index 11f7482..67fe21c 100644
--- a/03_exercise/srv/server.c
+++ b/03_exercise/srv/server.c
@@ -9,6 +9,18 @@
 
 #include "shell.h"
 
+/*
+ * READ ME
+ * What works:
+ *   - remote shell, weitesgehend die funktionalität der vorhergehenden aufgabe (damit auch pipes und background,
+ *      auch wenn wir das nicht ausführlich getestet haben)
+ *   - get und put für dateien
+ *   - mehrere clients an einem server
+ *  Known bugs:
+ *   - das erkennen, wann eine neue prompt geprintet werden muss ist aktuell sehr hacky client-seitig implementiert,
+ *      scheitert teilweise - die eingabe geht trzd ganz normal, es wird nur keine prompt angezeigt
+ */
+
 #define PORT 9000
 
 #define BUF_SIZE 256
@@ -19,13 +31,13 @@ static inline void die(const char *msg) {
 }
 
 int main() {
+    setvbuf(stderr, NULL, _IONBF, 0);
+    setvbuf(stdout, NULL, _IONBF, 0);
+
     struct sockaddr_in srv_addr, cli_addr;
-    int       sockopt = 1;
-    socklen_t sad_sz  = sizeof(struct sockaddr_in);
-    int       sfd, cfd;
-    /*ssize_t   bytes;
-    char      in_buf[BUF_SIZE];
-    char      out_buf[BUF_SIZE];*/
+    int                sockopt = 1;
+    socklen_t          sad_sz  = sizeof(struct sockaddr_in);
+    int                sfd;
 
     srv_addr.sin_family      = AF_INET;
     srv_addr.sin_port        = htons(PORT);
@@ -42,16 +54,36 @@ int main() {
     if (listen(sfd, 1) < 0)
         die("Could not listen on socket");
 
-    cfd = accept(sfd, (struct sockaddr *) &cli_addr, &sad_sz);
-    if (cfd < 0)
-        die("Could not accept incoming connection");
-
-    printf("srv: connected: %s\n", inet_ntoa(cli_addr.sin_addr));
-
-    int status = shell(cfd);
+    while (1) {
+        int cfd, pid;
+        cfd = accept(sfd, (struct sockaddr *) &cli_addr, &sad_sz);
+        if (cfd < 0) {
+            perror("Could not accept incoming connection");
+            break;
+        }
+
+        // fork new process
+        pid = fork();
+        if (pid < 0) {
+            perror("ERROR in new process creation");
+        }
+
+        if (pid == 0) {
+            // child process
+            close(sfd);
+
+            printf("srv: connected: %s\n", inet_ntoa(cli_addr.sin_addr));
+            int status = shell(cfd);
+            fprintf(stdout, "srv: client disconnected: %s (%d)\n", inet_ntoa(cli_addr.sin_addr), status);
+            fflush(stdout);
+            close(cfd);
+        } else {
+            // parent process
+            close(cfd);
+        }
+    }
 
-    close(cfd);
     close(sfd);
 
-    return status;
+    return 0;
 }
-- 
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