Reverse kms server connect direction to fix umask issue

4 files changed, 109 insertions, 82 deletions

diff --git a/kms/client/kms_client.c b/kms/client/kms_client.c
index 0b28b48..05cf8d7 100644
--- a/kms/client/kms_client.c
+++ b/kms/client/kms_client.c
@@ -174,12 +174,10 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
     int result = -1;
     self->kms_server_pid = -1;
     self->initial_socket_fd = -1;
-    self->initial_client_fd = -1;
     self->initial_socket_path[0] = '\0';
     self->socket_pair[0] = -1;
     self->socket_pair[1] = -1;
     struct sockaddr_un local_addr = {0};
-    struct sockaddr_un remote_addr = {0};
 
     if(!create_socket_path(self->initial_socket_path, sizeof(self->initial_socket_path))) {
         fprintf(stderr, "gsr error: gsr_kms_client_init: failed to create path to kms socket\n");
@@ -231,20 +229,6 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
     local_addr.sun_family = AF_UNIX;
     strncpy_safe(local_addr.sun_path, self->initial_socket_path, sizeof(local_addr.sun_path));
 
-    const mode_t prev_mask = umask(0000);
-    int bind_res = bind(self->initial_socket_fd, (struct sockaddr*)&local_addr, sizeof(local_addr.sun_family) + strlen(local_addr.sun_path));
-    umask(prev_mask);
-
-    if(bind_res == -1) {
-        fprintf(stderr, "gsr error: gsr_kms_client_init: failed to bind socket, error: %s\n", strerror(errno));
-        goto err;
-    }
-
-    if(listen(self->initial_socket_fd, 1) == -1) {
-        fprintf(stderr, "gsr error: gsr_kms_client_init: failed to listen on socket, error: %s\n", strerror(errno));
-        goto err;
-    }
-
     pid_t pid = fork();
     if(pid == -1) {
         fprintf(stderr, "gsr error: gsr_kms_client_init: fork failed, error: %s\n", strerror(errno));
@@ -271,41 +255,50 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
         self->kms_server_pid = pid;
     }
 
-    fprintf(stderr, "gsr info: gsr_kms_client_init: waiting for server to connect\n");
-    for(;;) {
-        struct timeval tv;
-        fd_set rfds;
-        FD_ZERO(&rfds);
-        FD_SET(self->initial_socket_fd, &rfds);
-
-        tv.tv_sec = 0;
-        tv.tv_usec = 100 * 1000; // 100 ms
-
-        int select_res = select(1 + self->initial_socket_fd, &rfds, NULL, NULL, &tv);
-        if(select_res > 0) {
-            socklen_t sock_len = 0;
-            self->initial_client_fd = accept(self->initial_socket_fd, (struct sockaddr*)&remote_addr, &sock_len);
-            if(self->initial_client_fd == -1) {
-                fprintf(stderr, "gsr error: gsr_kms_client_init: accept failed on socket, error: %s\n", strerror(errno));
-                goto err;
+    fprintf(stderr, "gsr info: connecting to the server\n");
+    bool connected = false;
+    while(true) {
+        struct sockaddr_un remote_addr = {0};
+        remote_addr.sun_family = AF_UNIX;
+        strncpy_safe(remote_addr.sun_path, self->initial_socket_path, sizeof(remote_addr.sun_path));
+        // TODO: Check if parent disconnected
+        if(connect(self->initial_socket_fd, (struct sockaddr*)&remote_addr, sizeof(remote_addr.sun_family) + strlen(remote_addr.sun_path)) == -1) {
+            if(errno == ECONNREFUSED || errno == ENOENT) {
+                goto next;
+            } else if(errno == EISCONN) {
+                connected = true;
+                break;
             }
+
+            fprintf(stderr, "gsr error: gsr_kms_client_init: connect failed, error: %s (%d)\n", strerror(errno), errno);
+            goto err;
+        }
+
+        next:
+        if(connected)
             break;
-        } else {
-            int status = 0;
-            int wait_result = waitpid(self->kms_server_pid, &status, WNOHANG);
-            if(wait_result != 0) {
-                int exit_code = -1;
-                if(WIFEXITED(status))
-                    exit_code = WEXITSTATUS(status);
-                fprintf(stderr, "gsr error: gsr_kms_client_init: kms server died or never started, exit code: %d\n", exit_code);
-                self->kms_server_pid = -1;
-                if(exit_code != 0)
-                    result = exit_code;
-                goto err;
-            }
+
+        int status = 0;
+        int wait_result = waitpid(self->kms_server_pid, &status, WNOHANG);
+        if(wait_result != 0) {
+            int exit_code = -1;
+            if(WIFEXITED(status))
+                exit_code = WEXITSTATUS(status);
+            fprintf(stderr, "gsr error: gsr_kms_client_init: kms server died or never started, exit code: %d\n", exit_code);
+            self->kms_server_pid = -1;
+            if(exit_code != 0)
+                result = exit_code;
+            goto err;
         }
+        usleep(30 * 1000); // 30 milliseconds
+    }
+
+    if(connected) {
+        fprintf(stderr, "gsr info: connected to the server\n");
+    } else {
+        fprintf(stderr, "gsr error: gsr_kms_client_init: failed to connect to the server\n");
+        goto err;
     }
-    fprintf(stderr, "gsr info: gsr_kms_client_init: server connected\n");
 
     fprintf(stderr, "gsr info: replacing file-backed unix domain socket with socketpair\n");
     if(gsr_kms_client_replace_connection(self) != 0)
@@ -322,11 +315,6 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
 }
 
 void cleanup_socket(gsr_kms_client *self, bool kill_server) {
-    if(self->initial_client_fd != -1) {
-        close(self->initial_client_fd);
-        self->initial_client_fd = -1;
-    }
-
     if(self->initial_socket_fd != -1) {
         close(self->initial_socket_fd);
         self->initial_socket_fd = -1;
@@ -366,7 +354,7 @@ int gsr_kms_client_replace_connection(gsr_kms_client *self) {
     request.version = GSR_KMS_PROTOCOL_VERSION;
     request.type = KMS_REQUEST_TYPE_REPLACE_CONNECTION;
     request.new_connection_fd = self->socket_pair[GSR_SOCKET_PAIR_REMOTE];
-    if(send_msg_to_server(self->initial_client_fd, &request) == -1) {
+    if(send_msg_to_server(self->initial_socket_fd, &request) == -1) {
         fprintf(stderr, "gsr error: gsr_kms_client_replace_connection: failed to send request message to server\n");
         return -1;
     }
diff --git a/kms/client/kms_client.h b/kms/client/kms_client.h
index 02f2dd1..27caca2 100644
--- a/kms/client/kms_client.h
+++ b/kms/client/kms_client.h
@@ -8,7 +8,6 @@
 typedef struct {
     pid_t kms_server_pid;
     int initial_socket_fd;
-    int initial_client_fd;
     char initial_socket_path[PATH_MAX];
     int socket_pair[2];
 } gsr_kms_client;
diff --git a/kms/kms_shared.h b/kms/kms_shared.h
index b72d75d..d31302b 100644
--- a/kms/kms_shared.h
+++ b/kms/kms_shared.h
@@ -4,7 +4,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-#define GSR_KMS_PROTOCOL_VERSION 1
+#define GSR_KMS_PROTOCOL_VERSION 2
 #define GSR_KMS_MAX_PLANES 32
 
 typedef enum {
diff --git a/kms/server/kms_server.c b/kms/server/kms_server.c
index 6062074..9a64543 100644
--- a/kms/server/kms_server.c
+++ b/kms/server/kms_server.c
@@ -9,6 +9,7 @@
 #include <fcntl.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <sys/stat.h>
 #include <time.h>
 
 #include <xf86drm.h>
@@ -361,6 +362,7 @@ static void strncpy_safe(char *dst, const char *src, int len) {
 int main(int argc, char **argv) {
     int res = 0;
     int socket_fd = 0;
+    int client_socket_fd = 0;
     gsr_drm drm;
     drm.drmfd = 0;
     drm.planes = NULL;
@@ -407,36 +409,59 @@ int main(int argc, char **argv) {
     c2crtc_map.num_maps = 0;
     map_crtc_to_connector_ids(&drm, &c2crtc_map);
 
-    fprintf(stderr, "kms server info: connecting to the client\n");
+    struct sockaddr_un local_addr = {0};
+    local_addr.sun_family = AF_UNIX;
+    strncpy_safe(local_addr.sun_path, domain_socket_path, sizeof(local_addr.sun_path));
+
+    const mode_t prev_mask = umask(0000);
+    const int bind_res = bind(socket_fd, (struct sockaddr*)&local_addr, sizeof(local_addr.sun_family) + strlen(local_addr.sun_path));
+    umask(prev_mask);
+
+    if(bind_res == -1) {
+        fprintf(stderr, "kms server error: failed to bind socket, error: %s\n", strerror(errno));
+        res = 2;
+        goto done;
+    }
+
+    if(listen(socket_fd, 1) == -1) {
+        fprintf(stderr, "kms server error: failed to listen on socket, error: %s\n", strerror(errno));
+        res = 2;
+        goto done;
+    }
+
+    fprintf(stderr, "kms server info: waiting for client to connect\n");
     bool connected = false;
     const double connect_timeout_sec = 5.0;
     const double start_time = clock_get_monotonic_seconds();
     while(clock_get_monotonic_seconds() - start_time < connect_timeout_sec) {
-        struct sockaddr_un remote_addr = {0};
-        remote_addr.sun_family = AF_UNIX;
-        strncpy_safe(remote_addr.sun_path, domain_socket_path, sizeof(remote_addr.sun_path));
-        // TODO: Check if parent disconnected
-        if(connect(socket_fd, (struct sockaddr*)&remote_addr, sizeof(remote_addr.sun_family) + strlen(remote_addr.sun_path)) == -1) {
-            if(errno == ECONNREFUSED || errno == ENOENT) {
-                goto next;
-            } else if(errno == EISCONN) {
-                connected = true;
-                break;
+        struct timeval tv;
+        fd_set rfds;
+        FD_ZERO(&rfds);
+        FD_SET(socket_fd, &rfds);
+
+        tv.tv_sec = 0;
+        tv.tv_usec = 100 * 1000; // 100 ms
+
+        int select_res = select(1 + socket_fd, &rfds, NULL, NULL, &tv);
+        if(select_res > 0) {
+            struct sockaddr_un remote_addr = {0};
+            socklen_t sock_len = 0;
+            client_socket_fd = accept(socket_fd, (struct sockaddr*)&remote_addr, &sock_len);
+            if(client_socket_fd == -1) {
+                fprintf(stderr, "kms server error: accept failed on socket, error: %s\n", strerror(errno));
+                res = 2;
+                goto done;
             }
 
-            fprintf(stderr, "kms server error: connect failed, error: %s (%d)\n", strerror(errno), errno);
-            res = 2;
-            goto done;
+            connected = true;
+            break;
         }
-
-        next:
-        usleep(30 * 1000); // 30 milliseconds
     }
 
     if(connected) {
-        fprintf(stderr, "kms server info: connected to the client\n");
+        fprintf(stderr, "kms server info: client connected\n");
     } else {
-        fprintf(stderr, "kms server error: failed to connect to the client in %f seconds\n", connect_timeout_sec);
+        fprintf(stderr, "kms server error: client failed to connect in %f seconds\n", connect_timeout_sec);
         res = 2;
         goto done;
     }
@@ -447,7 +472,7 @@ int main(int argc, char **argv) {
         request.type = -1;
         request.new_connection_fd = 0;
 
-        const int recv_res = recv_msg_from_client(socket_fd, &request);
+        const int recv_res = recv_msg_from_client(client_socket_fd, &request);
         if(recv_res == 0) {
             fprintf(stderr, "kms server info: kms client shutdown, shutting down the server\n");
             res = 3;
@@ -479,18 +504,29 @@ int main(int argc, char **argv) {
                 response.num_fds = 0;
 
                 if(request.new_connection_fd > 0) {
-                    if(socket_fd > 0)
+                    if(socket_fd > 0) {
                         close(socket_fd);
-                    socket_fd = request.new_connection_fd;
+                        socket_fd = -1;
+                    }
+
+                    if(client_socket_fd > 0)
+                        close(client_socket_fd);
+
+                    client_socket_fd = request.new_connection_fd;
 
                     response.result = KMS_RESULT_OK;
-                    if(send_msg_to_client(socket_fd, &response) == -1)
+                    if(send_msg_to_client(client_socket_fd, &response) == -1)
                         fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_REPLACE_CONNECTION request\n");
+
+                    if(domain_socket_path) {
+                        remove(domain_socket_path);
+                        domain_socket_path = NULL;
+                    }
                 } else {
                     response.result = KMS_RESULT_INVALID_REQUEST;
                     snprintf(response.err_msg, sizeof(response.err_msg), "received invalid connection fd");
                     fprintf(stderr, "kms server error: %s\n", response.err_msg);
-                    if(send_msg_to_client(socket_fd, &response) == -1)
+                    if(send_msg_to_client(client_socket_fd, &response) == -1)
                         fprintf(stderr, "kms server error: failed to respond to client request\n");
                 }
 
@@ -502,10 +538,10 @@ int main(int argc, char **argv) {
                 response.num_fds = 0;
                 
                 if(kms_get_fb(&drm, &response, &c2crtc_map) == 0) {
-                    if(send_msg_to_client(socket_fd, &response) == -1)
+                    if(send_msg_to_client(client_socket_fd, &response) == -1)
                         fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_GET_KMS request\n");
                 } else {
-                    if(send_msg_to_client(socket_fd, &response) == -1)
+                    if(send_msg_to_client(client_socket_fd, &response) == -1)
                         fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_GET_KMS request\n");
                 }
 
@@ -523,7 +559,7 @@ int main(int argc, char **argv) {
 
                 snprintf(response.err_msg, sizeof(response.err_msg), "invalid request type %d, expected %d (%s)", request.type, KMS_REQUEST_TYPE_GET_KMS, "KMS_REQUEST_TYPE_GET_KMS");
                 fprintf(stderr, "kms server error: %s\n", response.err_msg);
-                if(send_msg_to_client(socket_fd, &response) == -1)
+                if(send_msg_to_client(client_socket_fd, &response) == -1)
                     fprintf(stderr, "kms server error: failed to respond to client request\n");
 
                 break;
@@ -536,7 +572,11 @@ int main(int argc, char **argv) {
         drmModeFreePlaneResources(drm.planes);
     if(drm.drmfd > 0)
         close(drm.drmfd);
+    if(client_socket_fd > 0)
+        close(client_socket_fd);
     if(socket_fd > 0)
         close(socket_fd);
+    if(domain_socket_path)
+        remove(domain_socket_path);
     return res;
 }