From fda22526e2f492815f2cc4a539a785a5f884aac6 Mon Sep 17 00:00:00 2001
From: JacobBarthelmeh <jacob@wolfssl.com>
Date: Tue, 31 Oct 2023 14:42:09 -0600
Subject: [PATCH] add linux server side sending of exit-status

---
 apps/wolfsshd/wolfsshd.c | 12 ++++++++-
 src/internal.c           | 58 ++++++++++++++++++++++++++++++++++++++++
 src/ssh.c                | 15 +++++++++++
 wolfssh/internal.h       |  2 ++
 wolfssh/ssh.h            |  1 +
 5 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/apps/wolfsshd/wolfsshd.c b/apps/wolfsshd/wolfsshd.c
index b8b3673f..55184621 100644
--- a/apps/wolfsshd/wolfsshd.c
+++ b/apps/wolfsshd/wolfsshd.c
@@ -1308,7 +1308,7 @@ static int SHELL_Subsystem(WOLFSSHD_CONNECTION* conn, WOLFSSH* ssh,
             wolfSSH_Log(WS_LOG_ERROR, "[SSHD] Issue opening shell");
             exit(1);
         }
-        exit(0); /* exit child process and close down SSH connection */
+        exit(ret); /* exit child process and close down SSH connection */
     }
 
     /* do not wait for status of child process, and signal that the child can
@@ -1454,6 +1454,16 @@ static int SHELL_Subsystem(WOLFSSHD_CONNECTION* conn, WOLFSSH* ssh,
         }
     }
 
+    /* get return value of child process */
+    {
+        int waitStatus;
+        waitpid(-1, &waitStatus, WNOHANG);
+        if (wolfSSH_SendExitStatus(ssh, (word32)WEXITSTATUS(waitStatus)) !=
+                WS_SUCCESS) {
+            wolfSSH_Log(WS_LOG_ERROR, "[SSHD] Issue sending childs exit "
+                "status");
+        }
+    }
     (void)conn;
     return WS_SUCCESS;
 }
diff --git a/src/internal.c b/src/internal.c
index 4e69277f..ba11fc25 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -14034,6 +14034,64 @@ int SendChannelSuccess(WOLFSSH* ssh, word32 channelId, int success)
 }
 
 
+/* Sends out the channel exit-status msg
+ * returns WS_SUCCESS on success */
+int SendChannelExitStatus(WOLFSSH* ssh, word32 channelId, word32 exitStatus)
+{
+    byte* output;
+    word32 idx;
+    int ret = WS_SUCCESS;
+    WOLFSSH_CHANNEL* channel = NULL;
+    const char cType[] = "exit-status";
+    int typeSz;
+
+    WLOG(WS_LOG_DEBUG, "Entering SendChannelExitStatus()");
+    if (ssh == NULL)
+        ret = WS_BAD_ARGUMENT;
+
+    if (ret == WS_SUCCESS) {
+        channel = ChannelFind(ssh, channelId, WS_CHANNEL_ID_SELF);
+        if (channel == NULL) {
+            WLOG(WS_LOG_DEBUG, "Invalid channel");
+            ret = WS_INVALID_CHANID;
+        }
+    }
+
+    if (ret == WS_SUCCESS) {
+        typeSz = (word32)WSTRLEN(cType);
+        ret = PreparePacket(ssh, MSG_ID_SZ + UINT32_SZ + LENGTH_SZ +
+                                 typeSz + BOOLEAN_SZ + UINT32_SZ);
+    }
+
+    if (ret == WS_SUCCESS) {
+        output = ssh->outputBuffer.buffer;
+        idx = ssh->outputBuffer.length;
+
+        output[idx++] = MSGID_CHANNEL_REQUEST;
+        c32toa(channel->peerChannel, output + idx);
+        idx += UINT32_SZ;
+
+        c32toa(typeSz, output + idx);
+        idx += LENGTH_SZ;
+        WMEMCPY(output + idx, cType, typeSz);
+        idx += typeSz;
+        output[idx++] = 0; /* boolean of want reply is always false */
+        c32toa(exitStatus, output + idx);
+        idx += UINT32_SZ;
+
+        ssh->outputBuffer.length = idx;
+
+        ret = BundlePacket(ssh);
+    }
+
+    if (ret == WS_SUCCESS)
+        ret = wolfSSH_SendPacket(ssh);
+
+    WLOG(WS_LOG_DEBUG, "Leaving SendChannelExitStatus(), ret = %d", ret);
+    return ret;
+}
+
+
 #if (defined(WOLFSSH_SFTP) || defined(WOLFSSH_SCP)) && \
     !defined(NO_WOLFSSH_SERVER)
 /* cleans up absolute path
diff --git a/src/ssh.c b/src/ssh.c
index de760c02..a7e8e968 100644
--- a/src/ssh.c
+++ b/src/ssh.c
@@ -1375,6 +1375,21 @@ int wolfSSH_GetExitStatus(WOLFSSH* ssh)
     }
     return ssh->exitStatus;
 }
+
+
+/* Sends the commands exit status to the peer
+ * returns WS_SUCCESS on success */
+int wolfSSH_SendExitStatus(WOLFSSH* ssh, word32 exitStatus)
+{
+    if (ssh == NULL) {
+        WLOG(WS_LOG_DEBUG, "wolfSSH_SendExitStatus WOLFSSH struct was NULL");
+        return WS_BAD_ARGUMENT;
+    }
+    WLOG(WS_LOG_DEBUG, "wolfSSH_SendExitStatus sending exit status %u",
+        exitStatus);
+
+    return SendChannelExitStatus(ssh, ssh->defaultPeerChannelId, exitStatus);
+}
 #endif
 
 
diff --git a/wolfssh/internal.h b/wolfssh/internal.h
index 054c1e19..fe435b33 100644
--- a/wolfssh/internal.h
+++ b/wolfssh/internal.h
@@ -956,6 +956,8 @@ WOLFSSH_LOCAL int SendChannelTerminalResize(WOLFSSH*, word32, word32, word32,
 WOLFSSH_LOCAL int SendChannelTerminalRequest(WOLFSSH* ssh);
 WOLFSSH_LOCAL int SendChannelAgentRequest(WOLFSSH* ssh);
 WOLFSSH_LOCAL int SendChannelSuccess(WOLFSSH*, word32, int);
+WOLFSSH_LOCAL int SendChannelExitStatus(WOLFSSH* ssh, word32 channelId,
+    word32 exitStatus);
 WOLFSSH_LOCAL int GenerateKey(byte, byte, byte*, word32, const byte*, word32,
                               const byte*, word32, const byte*, word32, byte doKeyPad);
 
diff --git a/wolfssh/ssh.h b/wolfssh/ssh.h
index 6e57aa67..63c16574 100644
--- a/wolfssh/ssh.h
+++ b/wolfssh/ssh.h
@@ -294,6 +294,7 @@ WOLFSSH_API void wolfSSH_SetTerminalResizeCb(WOLFSSH* ssh,
     WS_CallbackTerminalSize cb);
 WOLFSSH_API void wolfSSH_SetTerminalResizeCtx(WOLFSSH* ssh, void* usrCtx);
 WOLFSSH_API int wolfSSH_GetExitStatus(WOLFSSH* ssh);
+WOLFSSH_API int wolfSSH_SendExitStatus(WOLFSSH* ssh, word32 exitStatus);
 
 
 enum WS_HighwaterSide {