[PATCH 18/33] Socket operations

Janani Venkataraman
2014-03-20T09:41:42Z

Creates a file socket using socket passing PF_UNIX, binds and then listens on
the connection.

Signed-off-by: Janani Venkataraman <jananive@linux.vnet.ibm.com>
---
src/Makefile.am | 3 +-
src/coredump.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 112 insertions(+), 1 deletion(-)

diff --git a/src/Makefile.am b/src/Makefile.am
index 90d8b25..b9b2e9b 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,6 +1,7 @@
AUTOMAKE_OPTIONS = foreign
HAVE_SYSTEMD_SOCKET_SUPPORT = 0
-CFLAGS += -I. -DHAVE_SYSTEMD_SOCKET_SUPPORT='$(HAVE_SYSTEMD_SOCKET_SUPPORT)'
+SOCKET_PATH = /var/run/gencored.socket
+CFLAGS += -I. -DHAVE_SYSTEMD_SOCKET_SUPPORT='$(HAVE_SYSTEMD_SOCKET_SUPPORT)' -DSOCKET_PATH='"$(SOCKET_PATH)"'

bin_PROGRAMS = gencore
gencore_SOURCES = coredump.c proc.c elf32.c elf64.c
diff --git a/src/coredump.c b/src/coredump.c
index 09fb8da..c992c66 100644
--- a/src/coredump.c
+++ b/src/coredump.c
@@ -33,8 +33,15 @@
#include <syslog.h>
#include <signal.h>
#include <sys/ptrace.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#include <coredump.h>

+/* Main Socket */
+int socket_fd;
+
/* For logging all the messages */
FILE *fp_log;

@@ -255,9 +262,98 @@ cleanup:
return ret;
}

+/* Creating a Unix socket */
+int create_socket(void)
+{
+ socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (socket_fd < 0) {
+ gencore_log("[%d]: Could not create a socket:%s.\n",
+ pid_log, strerror(errno));
+ return -1;
+ }
+
+ gencore_log("[%d]: Created socket.\n", pid_log);
+
+ return 0;
+}
+
+/* Binding the socket to a address */
+int bind_socket(void)
+{
+ struct sockaddr_un address;
+ struct stat buffer;
+ if (stat(SOCKET_PATH, &buffer) == 0)
+ unlink(SOCKET_PATH);
+
+ memset(&address, 0, sizeof(struct sockaddr_un));
+
+ address.sun_family = PF_FILE;
+ strcpy(address.sun_path, SOCKET_PATH);
+
+ if (bind(socket_fd, (struct sockaddr *) &address,
+ sizeof(struct sockaddr_un)) != 0) {
+ gencore_log("[%d]: Could not bind:%s.\n", pid_log,
+ strerror(errno));
+ close(socket_fd);
+ return -1;
+ }
+
+ if (chmod(SOCKET_PATH, S_IROTH | S_IWOTH
+ | S_IRUSR | S_IWUSR)) {
+ gencore_log("[%d]: Could not change permissions of socket:%s.\n",
+ pid_log, strerror(errno));
+ close(socket_fd);
+ return -1;
+ }
+
+ gencore_log("[%d]: Bind done.\n", pid_log);
+
+ return 0;
+}
+
+/* Listen for connections */
+int listen_conn(void)
+{
+ if (listen(socket_fd, 5) != 0) {
+ gencore_log("[%d]: Could not listen:%s.\n", pid_log,
+ strerror(errno));
+ close(socket_fd);
+ return -1;
+ }
+
+ gencore_log("[%d]: Listening.\n", pid_log);
+
+ return 0;
+}
+
+/* Setting up server */
+int setup_server(void)
+{
+ int ret;
+
+ /* Create Socket */
+ ret = create_socket();
+ if (ret)
+ return -1;
+
+ /* Bind Socket */
+ ret = bind_socket();
+ if (ret)
+ return -1;
+
+ /* Listen for connections */
+ ret = listen_conn();
+ if (ret)
+ return -1;
+
+ return 0;
+}
+
/* Daemon for self dump */
int daemon_dump(void)
{
+ int ret;
+
/* Check if daemon is running as root */
if (geteuid()) {
fprintf(stderr, "Run the daemon as root.\n");
@@ -282,7 +378,21 @@ int daemon_dump(void)
return -1;
}

+ /* Setting up server */
+ ret = setup_server();
+ if (ret)
+ goto cleanup;
+
+ /* Flush the log */
+ fflush(fp_log);
+
+cleanup:
+
fclose(fp_log);
+
+ if (ret == -1)
+ return -1;
+
return 0;
}