From ffc8a8702d9e1568995ce155c648fd029909cdac Mon Sep 17 00:00:00 2001
From: Tom Marshall <tdm@cyngn.com>
Date: Thu, 5 Nov 2015 21:30:40 -0800
Subject: recovery: Provide sideload cancellation

Change-Id: I13f0c9ae5444652a2141442ef24258679a78d320
---
 fuse_sideload.cpp | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

(limited to 'fuse_sideload.cpp')

diff --git a/fuse_sideload.cpp b/fuse_sideload.cpp
index 9c3e75f..39c7237 100644
--- a/fuse_sideload.cpp
+++ b/fuse_sideload.cpp
@@ -65,10 +65,8 @@
 #include "fuse_sideload.h"
 
 #define PACKAGE_FILE_ID   (FUSE_ROOT_ID+1)
-#define EXIT_FLAG_ID      (FUSE_ROOT_ID+2)
 
 #define NO_STATUS         1
-#define NO_STATUS_EXIT    2
 
 struct fuse_data {
     int ffd;   // file descriptor for the fuse socket
@@ -179,14 +177,12 @@ static int handle_getattr(void* /* data */, struct fuse_data* fd, const struct f
         fill_attr(&(out.attr), fd, hdr->nodeid, 4096, S_IFDIR | 0555);
     } else if (hdr->nodeid == PACKAGE_FILE_ID) {
         fill_attr(&(out.attr), fd, PACKAGE_FILE_ID, fd->file_size, S_IFREG | 0444);
-    } else if (hdr->nodeid == EXIT_FLAG_ID) {
-        fill_attr(&(out.attr), fd, EXIT_FLAG_ID, 0, S_IFREG | 0);
     } else {
         return -ENOENT;
     }
 
     fuse_reply(fd, hdr->unique, &out, sizeof(out));
-    return (hdr->nodeid == EXIT_FLAG_ID) ? NO_STATUS_EXIT : NO_STATUS;
+    return NO_STATUS;
 }
 
 static int handle_lookup(void* data, struct fuse_data* fd,
@@ -201,21 +197,15 @@ static int handle_lookup(void* data, struct fuse_data* fd,
         out.nodeid = PACKAGE_FILE_ID;
         out.generation = PACKAGE_FILE_ID;
         fill_attr(&(out.attr), fd, PACKAGE_FILE_ID, fd->file_size, S_IFREG | 0444);
-    } else if (strncmp(FUSE_SIDELOAD_HOST_EXIT_FLAG, reinterpret_cast<const char*>(data),
-                       sizeof(FUSE_SIDELOAD_HOST_EXIT_FLAG)) == 0) {
-        out.nodeid = EXIT_FLAG_ID;
-        out.generation = EXIT_FLAG_ID;
-        fill_attr(&(out.attr), fd, EXIT_FLAG_ID, 0, S_IFREG | 0);
     } else {
         return -ENOENT;
     }
 
     fuse_reply(fd, hdr->unique, &out, sizeof(out));
-    return (out.nodeid == EXIT_FLAG_ID) ? NO_STATUS_EXIT : NO_STATUS;
+    return NO_STATUS;
 }
 
 static int handle_open(void* /* data */, struct fuse_data* fd, const struct fuse_in_header* hdr) {
-    if (hdr->nodeid == EXIT_FLAG_ID) return -EPERM;
     if (hdr->nodeid != PACKAGE_FILE_ID) return -ENOENT;
 
     struct fuse_open_out out;
@@ -361,6 +351,12 @@ static int handle_read(void* data, struct fuse_data* fd, const struct fuse_in_he
     return NO_STATUS;
 }
 
+static volatile int terminated = 0;
+static void sig_term(int sig)
+{
+    terminated = 1;
+}
+
 int run_fuse_sideload(struct provider_vtab* vtab, void* cookie,
                       uint64_t file_size, uint32_t block_size)
 {
@@ -418,6 +414,8 @@ int run_fuse_sideload(struct provider_vtab* vtab, void* cookie,
         goto done;
     }
 
+    signal(SIGTERM, sig_term);
+
     fd.ffd = open("/dev/fuse", O_RDWR);
     if (fd.ffd < 0) {
         perror("open /dev/fuse");
@@ -438,7 +436,17 @@ int run_fuse_sideload(struct provider_vtab* vtab, void* cookie,
         goto done;
     }
     uint8_t request_buffer[sizeof(struct fuse_in_header) + PATH_MAX*8];
-    for (;;) {
+    while (!terminated) {
+        fd_set fds;
+        struct timeval tv;
+        FD_ZERO(&fds);
+        FD_SET(fd.ffd, &fds);
+        tv.tv_sec = 1;
+        tv.tv_usec = 0;
+        int rc = select(fd.ffd+1, &fds, NULL, NULL, &tv);
+        if (rc <= 0) {
+            continue;
+        }
         ssize_t len = TEMP_FAILURE_RETRY(read(fd.ffd, request_buffer, sizeof(request_buffer)));
         if (len == -1) {
             perror("read request");
@@ -493,11 +501,6 @@ int run_fuse_sideload(struct provider_vtab* vtab, void* cookie,
                 break;
         }
 
-        if (result == NO_STATUS_EXIT) {
-            result = 0;
-            break;
-        }
-
         if (result != NO_STATUS) {
             struct fuse_out_header outhdr;
             outhdr.len = sizeof(outhdr);
-- 
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