update: some loader/ code to C

This commit changes some code from "loader" folder to use C keywords and not C++ only keywords.

.gitignore

@@ -1,6 +1,7 @@
 .gradle
 .idea
 .cxx
+.vscode
 build
 local.properties
 Cargo.lock

loader/src/ptracer/main.cpp

@@ -1,55 +1,53 @@
-#include <cstdio>
-#include <cstdlib>
-#include <string_view>
-#include <unistd.h>
-#include <fcntl.h>
-#include <time.h>
-#include <sys/system_properties.h>
-
-#include "main.hpp"
+#include "main.h"
 #include "utils.hpp"
 #include "daemon.h"
-#include <sys/mount.h>
-
-using namespace std::string_view_literals;
 
 int main(int argc, char **argv) {
-    zygiskd::Init(getenv("TMP_PATH"));
-    if (argc >= 2 && argv[1] == "monitor"sv) {
-        init_monitor();
-        return 0;
-    } else if (argc >= 3 && argv[1] == "trace"sv) {
-        if (argc >= 4 && argv[3] == "--restart"sv) {
-            zygiskd::ZygoteRestart();
-        }
-        auto pid = strtol(argv[2], 0, 0);
-        if (!trace_zygote(pid)) {
-            kill(pid, SIGKILL);
-            return 1;
-        }
-        return 0;
-    } else if (argc >= 2 && argv[1] == "ctl"sv) {
-        if (argc == 3) {
-            if (argv[2] == "start"sv) {
-                send_control_command(START);
-                return 0;
-            } else if (argv[2] == "stop"sv) {
-                send_control_command(STOP);
-                return 0;
-            } else if (argv[2] == "exit"sv) {
-                send_control_command(EXIT);
-                return 0;
-            }
-        }
-        printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
-        printf("Usage: %s ctl start|stop|exit\n", argv[0]);
+  zygiskd::Init(getenv("TMP_PATH"));
+  if (argc >= 2 && strcmp(argv[1], "monitor") == 0) {
+    init_monitor();
+
+    return 0;
+  } else if (argc >= 3 && strcmp(argv[1], "trace") == 0) {
+      if (argc >= 4 && strcmp(argv[3], "--restart") == 0) zygiskd::ZygoteRestart();
+
+      long pid = strtol(argv[2], 0, 0);
+      if (!trace_zygote(pid)) {
+        kill(pid, SIGKILL);
+
         return 1;
-    } else if (argc >= 2 && argv[1] == "version"sv) {
-        printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
+      }
+
+      return 0;
+  } else if (argc >= 2 && strcmp(argv[1], "ctl") == 0) {
+    if (argc == 3) {
+      if (strcmp(argv[2], "start") == 0) {
+        send_control_command(START);
+
         return 0;
-    } else {
-        printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
-        printf("usage: %s monitor | trace <pid> | ctl <start|stop|exit> | version\n", argv[0]);
-        return 1;
+      } else if (strcmp(argv[2], "stop") == 0) {
+        send_control_command(STOP);
+
+        return 0;
+      } else if (strcmp(argv[2], "exit") == 0) {
+        send_control_command(EXIT);
+
+        return 0;
+      }
     }
+
+    printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
+    printf("Usage: %s ctl start|stop|exit\n", argv[0]);
+
+    return 1;
+  } else if (argc >= 2 && strcmp(argv[1], "version") == 0) {
+    printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
+
+    return 0;
+  } else {
+    printf("ReZygisk Tracer %s\n", ZKSU_VERSION);
+    printf("usage: %s monitor | trace <pid> | ctl <start|stop|exit> | version\n", argv[0]);
+
+    return 1;
+  }
 }

loader/src/ptracer/main.h

@@ -0,0 +1,26 @@
+#ifndef MAIN_HPP
+#define MAIN_HPP
+
+#include <stdbool.h>
+
+void init_monitor();
+bool trace_zygote(int pid);
+
+enum Command {
+  START = 1,
+  STOP = 2,
+  EXIT = 3,
+
+  /* sent from daemon */
+  ZYGOTE64_INJECTED = 4,
+  ZYGOTE32_INJECTED = 5,
+  DAEMON64_SET_INFO = 6,
+  DAEMON32_SET_INFO = 7,
+  DAEMON64_SET_ERROR_INFO = 8,
+  DAEMON32_SET_ERROR_INFO = 9,
+  SYSTEM_SERVER_STARTED = 10
+};
+
+void send_control_command(enum Command cmd);
+
+#endif /* MAIN_HPP */

loader/src/ptracer/main.hpp

@@ -1,21 +0,0 @@
-#pragma once
-
-
-void init_monitor();
-bool trace_zygote(int pid);
-
-enum Command {
-    START = 1,
-    STOP = 2,
-    EXIT = 3,
-    // sent from daemon
-    ZYGOTE64_INJECTED = 4,
-    ZYGOTE32_INJECTED = 5,
-    DAEMON64_SET_INFO = 6,
-    DAEMON32_SET_INFO = 7,
-    DAEMON64_SET_ERROR_INFO = 8,
-    DAEMON32_SET_ERROR_INFO = 9,
-    SYSTEM_SERVER_STARTED = 10
-};
-
-void send_control_command(Command cmd);

loader/src/ptracer/ptracer.cpp

@@ -161,7 +161,10 @@ bool inject_on_main(int pid, const char *lib_path) {
 
         return true;
     } else {
-        LOGE("stopped by other reason: %s", parse_status(status).c_str());
+        char status_str[64];
+        parse_status(status, status_str, sizeof(status_str));
+
+        LOGE("stopped by other reason: %s", status_str);
     }
     return false;
 }
@@ -205,12 +208,18 @@ bool trace_zygote(int pid) {
                 ptrace(PTRACE_DETACH, pid, 0, SIGCONT);
             }
         } else {
-            LOGE("unknown state %s, not SIGTRAP + EVENT_STOP", parse_status(status).c_str());
+            char status_str[64];
+            parse_status(status, status_str, sizeof(status_str));
+
+            LOGE("unknown state %s, not SIGTRAP + EVENT_STOP", status_str);
             ptrace(PTRACE_DETACH, pid, 0, 0);
             return false;
         }
     } else {
-        LOGE("unknown state %s, not SIGSTOP + EVENT_STOP", parse_status(status).c_str());
+        char status_str[64];
+        parse_status(status, status_str, sizeof(status_str));
+
+        LOGE("unknown state %s, not SIGSTOP + EVENT_STOP", status_str);
         ptrace(PTRACE_DETACH, pid, 0, 0);
         return false;
     }

loader/src/ptracer/utils.cpp

@@ -359,7 +359,10 @@ uintptr_t remote_call(int pid, struct user_regs_struct &regs, uintptr_t func_add
         }
         return regs.REG_RET;
     } else {
-        LOGE("stopped by other reason %s at addr %p", parse_status(status).c_str(), (void*) regs.REG_IP);
+        char status_str[64];
+        parse_status(status, status_str, sizeof(status_str));
+
+        LOGE("stopped by other reason %s at addr %p", status_str, (void*) regs.REG_IP);
     }
     return 0;
 }
@@ -394,42 +397,45 @@ void wait_for_trace(int pid, int* status, int flags) {
             }
         }
         if (!WIFSTOPPED(*status)) {
-            LOGE("process %d not stopped for trace: %s, exit", pid, parse_status(*status).c_str());
+            char status_str[64];
+            parse_status(*status, status_str, sizeof(status_str));
+
+            LOGE("process %d not stopped for trace: %s, exit", pid, status_str);
             exit(1);
         }
         return;
     }
 }
 
-std::string parse_status(int status) {
-    std::ostringstream os;
-    os << "0x" << std::hex << status << std::dec << " ";
-    if (WIFEXITED(status)) {
-        os << "exited with " << WEXITSTATUS(status);
-    } else if (WIFSIGNALED(status)) {
-        os << "signaled with " << sigabbrev_np(WTERMSIG(status)) << "(" << WTERMSIG(status) << ")";
-    } else if (WIFSTOPPED(status)) {
-        os << "stopped by ";
-        auto stop_sig = WSTOPSIG(status);
-        os << "signal=" << sigabbrev_np(stop_sig) << "(" << stop_sig << "),";
-        os << "event=" << parse_ptrace_event(status);
-    } else {
-        os << "unknown";
-    }
-    return os.str();
+void parse_status(int status, char *buf, size_t len) {
+  snprintf(buf, len, "0x%x ", status);
+  if (WIFEXITED(status)) {
+    snprintf(buf + strlen(buf), len - strlen(buf), "exited with %d", WEXITSTATUS(status));
+  } else if (WIFSIGNALED(status)) {
+    snprintf(buf + strlen(buf), len - strlen(buf), "signaled with %s(%d)", sigabbrev_np(WTERMSIG(status)), WTERMSIG(status));
+  } else if (WIFSTOPPED(status)) {
+    snprintf(buf + strlen(buf), len - strlen(buf), "stopped by ");
+    auto stop_sig = WSTOPSIG(status);
+    snprintf(buf + strlen(buf), len - strlen(buf), "signal=%s(%d),", sigabbrev_np(stop_sig), stop_sig);
+    snprintf(buf + strlen(buf), len - strlen(buf), "event=%s", parse_ptrace_event(status));
+  } else {
+    snprintf(buf + strlen(buf), len - strlen(buf), "unknown");
+  }
 }
 
-std::string get_program(int pid) {
-    std::string path = "/proc/";
-    path += std::to_string(pid);
-    path += "/exe";
-    constexpr const auto SIZE = 256;
-    char buf[SIZE + 1];
-    auto sz = readlink(path.c_str(), buf, SIZE);
-    if (sz == -1) {
-        PLOGE("readlink /proc/%d/exe", pid);
-        return "";
-    }
-    buf[sz] = 0;
-    return buf;
+int get_program(int pid, char *buf, size_t size) {
+  char path[64];
+  snprintf(path, sizeof(path), "/proc/%d/exe", pid);
+
+  ssize_t sz = readlink(path, buf, size);
+
+  if (sz == -1) {
+    PLOGE("readlink /proc/%d/exe", pid);
+
+    return -1;
+  }
+
+  buf[sz] = 0;
+
+  return 0;
 }

loader/src/ptracer/utils.hpp

@@ -89,7 +89,7 @@ int fork_dont_care();
 
 void wait_for_trace(int pid, int* status, int flags);
 
-std::string parse_status(int status);
+void parse_status(int status, char *buf, size_t len);
 
 #define WPTEVENT(x) (x >> 16)
 
@@ -116,7 +116,7 @@ inline const char* sigabbrev_np(int sig) {
     return "(unknown)";
 }
 
-std::string get_program(int pid);
+int get_program(int pid, char *buf, size_t size);
 void *find_module_return_addr(std::vector<MapInfo> &info, std::string_view suffix);
 
 // pid = 0, fd != nullptr -> set to fd