Move kms client and server to separate directories

1 files changed, 244 insertions, 0 deletions

diff --git a/kms/server/kms_server.c b/kms/server/kms_server.c
new file mode 100644
index 0000000..73cf9d0
--- /dev/null
+++ b/kms/server/kms_server.c
@@ -0,0 +1,244 @@
+#include "../kms_shared.h"
+
+#include <asm-generic/socket.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#define DRM_CLIENT_CAP_UNIVERSAL_PLANES 2
+
+static int max_int(int a, int b) {
+    return a > b ? a : b;
+}
+
+static int send_msg_to_client(int client_fd, gsr_kms_response *response, int *fds, int num_fds) {
+    struct iovec iov;
+    iov.iov_base = response;
+    iov.iov_len = sizeof(*response);
+
+    struct msghdr response_message = {0};
+    response_message.msg_iov = &iov;
+    response_message.msg_iovlen = 1;
+
+    char cmsgbuf[CMSG_SPACE(sizeof(int)) * max_int(1, num_fds)];
+    memset(cmsgbuf, 0, sizeof(cmsgbuf));
+
+    if(num_fds > 0) {
+        response_message.msg_control = cmsgbuf;
+        response_message.msg_controllen = sizeof(cmsgbuf);
+
+        int total_msg_len = 0;
+        struct cmsghdr *cmsg = NULL;
+        for(int i = 0; i < num_fds; ++i) {
+            if(i == 0)
+                cmsg = CMSG_FIRSTHDR(&response_message);
+            else
+                cmsg = CMSG_NXTHDR(&response_message, cmsg);
+
+            cmsg->cmsg_level = SOL_SOCKET;
+            cmsg->cmsg_type = SCM_RIGHTS;
+            cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+            memcpy(CMSG_DATA(cmsg), &fds[i], sizeof(int));
+            total_msg_len += cmsg->cmsg_len;
+        }
+
+        response_message.msg_controllen = total_msg_len;
+    }
+
+    return sendmsg(client_fd, &response_message, 0);
+}
+
+static int get_kms(const char *card_path, gsr_kms_response *response) {
+    response->result = KMS_RESULT_OK;
+    response->data.fd.fd = 0;
+    response->data.fd.width = 0;
+    response->data.fd.height = 0;
+
+    const int drmfd = open(card_path, O_RDONLY);
+    if (drmfd < 0) {
+        response->result = KMS_RESULT_FAILED_TO_OPEN_CARD;
+        snprintf(response->data.err_msg, sizeof(response->data.err_msg), "failed to open %s, error: %s", card_path, strerror(errno));
+        return -1;
+    }
+
+    if (0 != drmSetClientCap(drmfd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1)) {
+        response->result = KMS_RESULT_INSUFFICIENT_PERMISSIONS;
+        snprintf(response->data.err_msg, sizeof(response->data.err_msg), "drmSetClientCap failed, error: %s", strerror(errno));
+        close(drmfd);
+        return -1;
+    }
+
+    drmModePlaneResPtr planes = drmModeGetPlaneResources(drmfd);
+    if (!planes) {
+        response->result = KMS_RESULT_FAILED_TO_GET_KMS;
+        snprintf(response->data.err_msg, sizeof(response->data.err_msg), "failed to access planes, error: %s", strerror(errno));
+        close(drmfd);
+        return -1;
+    }
+
+    fprintf(stderr, "DRM planes %d:\n", planes->count_planes);
+    for (uint32_t i = 0; i < planes->count_planes; ++i) {
+        drmModePlanePtr plane = drmModeGetPlane(drmfd, planes->planes[i]);
+        if (!plane) {
+            fprintf(stderr, "Cannot get drmModePlanePtr for plane %#x: %s (%d)\n", planes->planes[i], strerror(errno), errno);
+            continue;
+        }
+
+        fprintf(stderr, "\t%d: fb_id=%#x\n", i, plane->fb_id);
+
+        if (!plane->fb_id)
+            goto plane_continue;
+
+        drmModeFB2Ptr drmfb = drmModeGetFB2(drmfd, plane->fb_id);
+        if (!drmfb) {
+            fprintf(stderr, "Cannot get drmModeFBPtr for fb %#x: %s (%d)\n", plane->fb_id, strerror(errno), errno);
+        } else {
+            if (!drmfb->handles[0]) {
+                fprintf(stderr, "\t\tFB handle for fb %#x is NULL\n", plane->fb_id);
+                fprintf(stderr, "\t\tPossible reason: not permitted to get FB handles. Do `sudo setcap cap_sys_admin+ep`\n");
+            } else {
+                int fb_fd = -1;
+                const int ret = drmPrimeHandleToFD(drmfd, drmfb->handles[0], 0, &fb_fd);
+                if (ret != 0 || fb_fd == -1) {
+                    fprintf(stderr, "Cannot get fd for fb %#x handle %#x: %s (%d)\n", plane->fb_id, drmfb->handles[0], strerror(errno), errno);
+                } else if(drmfb->width * drmfb->height > response->data.fd.width * response->data.fd.height) {
+                    if(response->data.fd.fd != 0) {
+                        close(response->data.fd.fd);
+                        response->data.fd.fd = 0;
+                    }
+
+                    response->data.fd.fd = fb_fd;
+                    response->data.fd.width = drmfb->width;
+                    response->data.fd.height = drmfb->height;
+                    response->data.fd.pitch = drmfb->pitches[0];
+                    response->data.fd.offset = drmfb->offsets[0];
+                    response->data.fd.pixel_format = drmfb->pixel_format;
+                    response->data.fd.modifier = drmfb->modifier;
+                    fprintf(stderr, "kms width: %u, height: %u, pixel format: %u, modifier: %lu\n", response->data.fd.width, response->data.fd.height, response->data.fd.pixel_format, response->data.fd.modifier);
+                } else {
+                    close(fb_fd);
+                }
+            }
+            drmModeFreeFB2(drmfb);
+        }
+
+    plane_continue:
+        drmModeFreePlane(plane);
+    }
+
+    drmModeFreePlaneResources(planes);
+    close(drmfd);
+
+    if(response->data.fd.fd == 0) {
+        response->result = KMS_RESULT_NO_KMS_AVAILABLE;
+        snprintf(response->data.err_msg, sizeof(response->data.err_msg), "no kms found");
+        return -1;
+    }
+
+    return 0;
+}
+
+int main(int argc, char **argv) {
+    if(argc != 2) {
+        fprintf(stderr, "usage: kms_server <domain_socket_path>\n");
+        return 1;
+    }
+
+    const char *domain_socket_path = argv[1];
+    int socket_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if(socket_fd == -1) {
+        fprintf(stderr, "kms server error: failed to create socket, error: %s\n", strerror(errno));
+        return 2;
+    }
+
+    fprintf(stderr, "kms server info: connecting to the server\n");
+    for(;;) {
+        struct sockaddr_un remote_addr = {0};
+        remote_addr.sun_family = AF_UNIX;
+        strncpy(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)
+                continue; // Host not ready yet? TODO: sleep
+            if(errno == EISCONN) // TODO?
+                break;
+            fprintf(stderr, "kms server error: connect failed, error: %s (%d)\n", strerror(errno), errno);
+            return 2;
+        }
+    }
+    fprintf(stderr, "kms server info: connected to the server\n");
+
+    int res = 0;
+    for(;;) {
+        gsr_kms_request request;
+        struct iovec iov;
+        iov.iov_base = &request;
+        iov.iov_len = sizeof(request);
+
+        struct msghdr request_message = {0};
+        request_message.msg_iov = &iov;
+        request_message.msg_iovlen = 1;
+        const int recv_res = recvmsg(socket_fd, &request_message, MSG_WAITALL);
+        if(recv_res == 0) {
+            fprintf(stderr, "kms server info: kms client shutdown, shutting down the server\n");
+            res = 3;
+            goto done;
+        } else if(recv_res == -1) {
+            const int err = errno;
+            fprintf(stderr, "kms server error: failed to read all data in client request (error: %s), ignoring\n", strerror(err));
+            if(err == EBADF) {
+                fprintf(stderr, "kms server error: invalid client fd, shutting down the server\n");
+                res = 3;
+                goto done;
+            }
+            continue;
+        }
+        request.data.card_path[254] = '\0';
+
+        switch(request.type) {
+            case KMS_REQUEST_TYPE_GET_KMS: {
+                gsr_kms_response response;
+                int kms_fd = 0;
+                if (get_kms(request.data.card_path, &response) == 0) {
+                    kms_fd = response.data.fd.fd;
+                }
+
+                if(send_msg_to_client(socket_fd, &response, &kms_fd, kms_fd == 0 ? 0 : 1) == -1) {
+                    fprintf(stderr, "kms server error: failed to respond to client KMS_REQUEST_TYPE_GET_KMS request\n");
+                    if(kms_fd != 0)
+                        close(kms_fd);
+                    break;
+                }
+
+                if(kms_fd != 0)
+                    close(kms_fd);
+
+                break;
+            }
+            default: {
+                gsr_kms_response response;
+                response.result = KMS_RESULT_INVALID_REQUEST;
+                snprintf(response.data.err_msg, sizeof(response.data.err_msg), "invalid request type %d, expected %d (%s)", request.type, KMS_REQUEST_TYPE_GET_KMS, "KMS_REQUEST_TYPE_GET_KMS");
+                fprintf(stderr, "%s\n", response.data.err_msg);
+                if(send_msg_to_client(socket_fd, &response, NULL, 0) == -1) {
+                    fprintf(stderr, "kms server error: failed to respond to client request\n");
+                    break;
+                }
+                break;
+            }
+        }
+    }
+
+    done:
+    close(socket_fd);
+    return res;
+}