Log to zygiskd

loader/src/common/daemon.cpp

@@ -29,7 +29,6 @@ namespace zygiskd {
     }
 
     bool PingHeartbeat() {
-        LOGD("Daemon socket: %s", kZygiskSocket.data());
         UniqueFd fd = Connect(5);
         if (fd == -1) {
             PLOGE("Connect to zygiskd");
@@ -39,6 +38,16 @@ namespace zygiskd {
         return true;
     }
 
+    int RequestLogcatFd() {
+        int fd = Connect(1);
+        if (fd == -1) {
+            PLOGE("RequestLogcatFd");
+            return -1;
+        }
+        socket_utils::write_u8(fd, (uint8_t) SocketAction::RequestLogcatFd);
+        return fd;
+    }
+
     std::string ReadNativeBridge() {
         UniqueFd fd = Connect(1);
         if (fd == -1) {

loader/src/common/logging.cpp

@@ -0,0 +1,36 @@
+#include <android/log.h>
+#include <unistd.h>
+
+#include "logging.h"
+#include "socket_utils.h"
+
+namespace logging {
+    static int logfd = -1;
+
+    void setfd(int fd) {
+        close(logfd);
+        logfd = fd;
+    }
+
+    int getfd() {
+        return logfd;
+    }
+
+    void log(int prio, const char* tag, const char* fmt, ...) {
+        if (logfd == -1) {
+            va_list ap;
+            va_start(ap, fmt);
+            __android_log_vprint(prio, tag, fmt, ap);
+            va_end(ap);
+        } else {
+            char buf[BUFSIZ];
+            va_list ap;
+            va_start(ap, fmt);
+            vsnprintf(buf, sizeof(buf), fmt, ap);
+            va_end(ap);
+            socket_utils::write_u8(logfd, prio);
+            socket_utils::write_string(logfd, tag);
+            socket_utils::write_string(logfd, buf);
+        }
+    }
+}

loader/src/common/socket_utils.cpp

@@ -110,6 +110,10 @@ namespace socket_utils {
         return write_exact<uint8_t>(fd, val);
     }
 
+    bool write_string(int fd, std::string_view str) {
+        return write_usize(fd, str.size()) && str.size() == xwrite(fd, str.data(), str.size());
+    }
+
     int recv_fd(int sockfd) {
         char cmsgbuf[CMSG_SPACE(sizeof(int))];