Release Vulpes OS 2.7-preview.22

tundra/probes/beatles-control-client.c

@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: MPL-2.0 */
+/* Unprivileged one-request relay. The root broker still validates every command. */
+#define _POSIX_C_SOURCE 200809L
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#define REQUEST_LIMIT 8192
+#define RESPONSE_LIMIT 65536
+
+static int write_all(int fd, const char *data, size_t size) {
+  while (size) {
+    ssize_t count=write(fd,data,size);
+    if (count<0 && errno==EINTR) continue;
+    if (count<=0) return -1;
+    data+=count;size-=(size_t)count;
+  }
+  return 0;
+}
+
+int main(int argc,char **argv) {
+  const char *path;
+  if (argc!=2) return 2;
+  if (!strcmp(argv[1],"--radio")) path="/work/phone-control.sock";
+  else if (!strcmp(argv[1],"--wifi")) path="/work/wifi-control.sock";
+  else return 2;
+  signal(SIGPIPE,SIG_IGN);
+  /* Bound the whole exchange, including a truncated stdin or an unresponsive broker. */
+  alarm(40);
+  char request[REQUEST_LIMIT+1];size_t used=0;
+  for (;;) {
+    ssize_t count=read(STDIN_FILENO,request+used,sizeof(request)-used);
+    if (count<0 && errno==EINTR) continue;
+    if (count<0) return 1;
+    if (!count) break;
+    used+=(size_t)count;
+    if (used>REQUEST_LIMIT) return 2;
+  }
+  if (!used || memchr(request,'\n',used) || memchr(request,'\r',used)) return 2;
+  int fd=socket(AF_UNIX,SOCK_STREAM,0);
+  if (fd<0) return 1;
+  struct sockaddr_un address={.sun_family=AF_UNIX};
+  memcpy(address.sun_path,path,strlen(path)+1);
+  if (connect(fd,(struct sockaddr *)&address,sizeof(address)) ||
+      write_all(fd,request,used) || write_all(fd,"\n",1)) {close(fd);return 1;}
+  char response[RESPONSE_LIMIT+1];used=0;
+  for (;;) {
+    ssize_t count=read(fd,response+used,sizeof(response)-used);
+    if (count<0 && errno==EINTR) continue;
+    if (count<=0) {close(fd);return 1;}
+    used+=(size_t)count;
+    if (used>RESPONSE_LIMIT) {close(fd);return 1;}
+    char *end=memchr(response,'\n',used);
+    if (end) {
+      int result=write_all(STDOUT_FILENO,response,(size_t)(end-response)+1);
+      close(fd);return result?1:0;
+    }
+  }
+}