Minor code refactoring

native/jni/su/connect.cpp

@@ -30,7 +30,7 @@ enum {
 ? info->uid / 100000 : 0)
 
 #define get_cmd(to) \
-(to.command[0] ? to.command : to.shell[0] ? to.shell : DEFAULT_SHELL)
+(to.command.empty() ? (to.shell.empty() ? DEFAULT_SHELL : to.shell.data()) : to.command.data())
 
 class Extra {
     const char *key;
@@ -42,7 +42,7 @@ class Extra {
     union {
         int int_val;
         bool bool_val;
-        const char * str_val;
+        const char *str_val;
     };
     char buf[32];
 public:

native/jni/su/su.cpp

@@ -43,18 +43,6 @@ static void usage(int status) {
     exit(status);
 }
 
-static char *concat_commands(int argc, char *argv[]) {
-    char command[ARG_MAX];
-    command[0] = '\0';
-    for (int i = optind - 1; i < argc; ++i) {
-        if (command[0])
-            sprintf(command, "%s %s", command, argv[i]);
-        else
-            strcpy(command, argv[i]);
-    }
-    return strdup(command);
-}
-
 static void sighandler(int sig) {
     restore_stdin();
 
@@ -114,7 +102,13 @@ int su_client_main(int argc, char *argv[]) {
     while ((c = getopt_long(argc, argv, "c:hlmps:Vvuz:M", long_opts, nullptr)) != -1) {
         switch (c) {
             case 'c':
-                su_req.command = concat_commands(argc, argv);
+                for (int i = optind - 1; i < argc; ++i) {
+                    if (!su_req.command.empty())
+                        su_req.command += ' ';
+                    su_req.command += '\'';
+                    su_req.command += argv[i];
+                    su_req.command += '\'';
+                }
                 optind = argc;
                 break;
             case 'h':

native/jni/su/su.hpp

@@ -45,19 +45,9 @@ struct su_req_base {
 } __attribute__((packed));
 
 struct su_request : public su_req_base {
-    const char *shell = DEFAULT_SHELL;
-    const char *command = "";
-    su_request(bool dyn = false) : dyn(dyn) {}
-    ~su_request() {
-        if (dyn) {
-            free(const_cast<char*>(shell));
-            free(const_cast<char*>(command));
-        }
-    }
-
-private:
-    bool dyn;
-} __attribute__((packed));
+    std::string shell = DEFAULT_SHELL;
+    std::string command;
+};
 
 struct su_context {
     std::shared_ptr<su_info> info;

native/jni/su/su_daemon.cpp

@@ -163,14 +163,14 @@ void su_daemon_handler(int client, struct ucred *credential) {
 
     su_context ctx = {
         .info = get_su_info(credential->uid),
-        .req = su_request(true),
+        .req = su_request(),
         .pid = credential->pid
     };
 
     // Read su_request
     xxread(client, &ctx.req, sizeof(su_req_base));
-    ctx.req.shell = read_string(client);
-    ctx.req.command = read_string(client);
+    read_string(client, ctx.req.shell);
+    read_string(client, ctx.req.command);
 
     if (ctx.info->access.log)
         app_log(ctx);
@@ -223,18 +223,18 @@ void su_daemon_handler(int client, struct ucred *credential) {
     xsetsid();
 
     // Get pts_slave
-    char *pts_slave = read_string(client);
+    string pts_slave = read_string(client);
 
     // The FDs for each of the streams
     int infd  = recv_fd(client);
     int outfd = recv_fd(client);
     int errfd = recv_fd(client);
 
-    if (pts_slave[0]) {
-        LOGD("su: pts_slave=[%s]\n", pts_slave);
+    if (!pts_slave.empty()) {
+        LOGD("su: pts_slave=[%s]\n", pts_slave.data());
         // Check pts_slave file is owned by daemon_from_uid
         struct stat st;
-        xstat(pts_slave, &st);
+        xstat(pts_slave.data(), &st);
 
         // If caller is not root, ensure the owner of pts_slave is the caller
         if(st.st_uid != ctx.info->uid && ctx.info->uid != 0)
@@ -243,7 +243,7 @@ void su_daemon_handler(int client, struct ucred *credential) {
         // Opening the TTY has to occur after the
         // fork() and setsid() so that it becomes
         // our controlling TTY and not the daemon's
-        int ptsfd = xopen(pts_slave, O_RDWR);
+        int ptsfd = xopen(pts_slave.data(), O_RDWR);
 
         if (infd < 0)
             infd = ptsfd;
@@ -253,8 +253,6 @@ void su_daemon_handler(int client, struct ucred *credential) {
             errfd = ptsfd;
     }
 
-    free(pts_slave);
-
     // Swap out stdin, stdout, stderr
     xdup2(infd, STDIN_FILENO);
     xdup2(outfd, STDOUT_FILENO);
@@ -290,13 +288,13 @@ void su_daemon_handler(int client, struct ucred *credential) {
             break;
     }
 
-    const char *argv[] = { nullptr, nullptr, nullptr, nullptr };
+    const char *argv[4] = { nullptr };
 
-    argv[0] = ctx.req.login ? "-" : ctx.req.shell;
+    argv[0] = ctx.req.login ? "-" : ctx.req.shell.data();
 
-    if (ctx.req.command[0]) {
+    if (!ctx.req.command.empty()) {
         argv[1] = "-c";
-        argv[2] = ctx.req.command;
+        argv[2] = ctx.req.command.data();
     }
 
     // Setup environment
@@ -321,7 +319,7 @@ void su_daemon_handler(int client, struct ucred *credential) {
             setenv("HOME", pw->pw_dir, 1);
             setenv("USER", pw->pw_name, 1);
             setenv("LOGNAME", pw->pw_name, 1);
-            setenv("SHELL", ctx.req.shell, 1);
+            setenv("SHELL", ctx.req.shell.data(), 1);
         }
     }
 
@@ -330,8 +328,8 @@ void su_daemon_handler(int client, struct ucred *credential) {
     sigemptyset(&block_set);
     sigprocmask(SIG_SETMASK, &block_set, nullptr);
     set_identity(ctx.req.uid);
-    execvp(ctx.req.shell, (char **) argv);
-    fprintf(stderr, "Cannot execute %s: %s\n", ctx.req.shell, strerror(errno));
+    execvp(ctx.req.shell.data(), (char **) argv);
+    fprintf(stderr, "Cannot execute %s: %s\n", ctx.req.shell.data(), strerror(errno));
     PLOGE("exec");
     exit(EXIT_FAILURE);
 }