[PATCH 20/33] Handling Requests

Janani Venkataraman
2014-03-20T09:47:44Z

Accepting requests and then spawning a new thread to service them.

Signed-off-by: Janani Venkataraman <jananive@linux.vnet.ibm.com>
---
src/coredump.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 110 insertions(+)
mode change 100644 => 100755 src/coredump.c

diff --git a/src/coredump.c b/src/coredump.c
old mode 100644
new mode 100755
index d93f4b2..fadb7cd
--- a/src/coredump.c
+++ b/src/coredump.c
@@ -42,6 +42,11 @@
/* Main Socket */
int socket_fd;

+/* Accepted Socket */
+int new_sock;
+
+#define CORE_FILE_NAME_SZ 1000 /* Size of core file name */
+
/* For logging all the messages */
FILE *fp_log;

@@ -381,6 +386,100 @@ int block_on_request(void)
return 0;
}

+/* Handles a SIGCHILD */
+void sigchild_handler(int sig)
+{
+ int pid;
+
+ pid = waitpid(0, &status, WNOHANG);
+
+ gencore_log("[%d]: Request handled by child with PID:%d and exited.\n",
+ pid_log, pid);
+}
+
+/* Sends message to client */
+int send_reply(int err)
+{
+ if (write(new_sock, &err , sizeof(err)) == -1) {
+ gencore_log("[%d]: Could not send message:%s\n",
+ pid_log, strerror(errno));
+ return -1;
+ }
+
+ gencore_log("[%d]: Message sent:%d\n", pid_log, err);
+
+ return 0;
+}
+
+/* Receive message from client */
+int receive_core_filename(char *core_file)
+{
+ memset(core_file, 0, CORE_FILE_NAME_SZ);
+ if (read(new_sock, core_file , CORE_FILE_NAME_SZ) == -1) {
+ send_reply(errno);
+ gencore_log("[%d]: Could not get Core file name:%s\n",
+ pid_log, strerror(errno));
+ return -1;
+ }
+
+ gencore_log("[%d]: Core file path received:%s\n", pid_log,
+ core_file);
+ /* Sending the acknowledgment */
+ send_reply(0);
+
+ return 0;
+}
+
+/* Services requests */
+int service_request(void)
+{
+ int ret;
+ char core_file[CORE_FILE_NAME_SZ];
+
+ /* Receive the message */
+ ret = receive_core_filename(core_file);
+ if (ret)
+ goto cleanup;
+
+cleanup:
+ close(new_sock);
+ if (ret == -1)
+ exit(EXIT_FAILURE);
+
+ exit(EXIT_SUCCESS);
+}
+
+/* Handles new requests */
+int handle_request(void)
+{
+ int pid_new;
+ struct sockaddr_un client_address;
+ socklen_t client_size = sizeof(client_address);
+
+ new_sock = accept(socket_fd, (struct sockaddr *) &client_address,
+ &client_size);
+ if (new_sock < 0) {
+ gencore_log("[%d]: Could not accept:%s\n", pid_log,
+ strerror(errno));
+ close(socket_fd);
+ fclose(fp_log);
+ return -1;
+ }
+
+ gencore_log("[%d]: Accepted.\n", pid_log);
+
+ gencore_log("[%d]: Handling request.\n", pid_log);
+
+ /* New thread to service request */
+ pid_new = fork();
+ if (pid_new == 0) {
+ pid_log = getpid();
+ service_request();
+ }
+
+ return 0;
+}
+
/* Daemon for self dump */
int daemon_dump(void)
{
@@ -418,6 +517,9 @@ int daemon_dump(void)
/* Flush the log */
fflush(fp_log);

+ /* SIGCHILD - Signal handler */
+ signal(SIGCHLD, sigchild_handler);
+
while (1) {

/* Blocks on request */
@@ -427,6 +529,14 @@ int daemon_dump(void)

/* Flush the log */
fflush(fp_log);
+
+ /* Handle new connections */
+ ret = handle_request();
+ if (ret)
+ goto cleanup;
+
+ /* Flush the log */
+ fflush(fp_log);
}

return 0;