nghttpx: Don't exit from save_pid and set_alpn_prefs

src/shrpx.cc

@@ -294,7 +294,7 @@ int chown_to_running_user(const char *path) {
 } // namespace
 
 namespace {
-void save_pid() {
+int save_pid() {
   constexpr auto SUFFIX = StringRef::from_lit(".XXXXXX");
   auto &pid_file = get_config()->pid_file;
 
@@ -313,7 +313,7 @@ void save_pid() {
     auto error = errno;
     LOG(ERROR) << "Could not save PID to file " << pid_file << ": "
                << strerror(error);
-    exit(EXIT_FAILURE);
+    return -1;
   }
 
   auto content = util::utos(get_config()->pid) + '\n';
@@ -322,14 +322,14 @@ void save_pid() {
     auto error = errno;
     LOG(ERROR) << "Could not save PID to file " << pid_file << ": "
                << strerror(error);
-    exit(EXIT_FAILURE);
+    return -1;
   }
 
   if (fsync(fd) == -1) {
     auto error = errno;
     LOG(ERROR) << "Could not save PID to file " << pid_file << ": "
                << strerror(error);
-    exit(EXIT_FAILURE);
+    return -1;
   }
 
   close(fd);
@@ -341,7 +341,7 @@ void save_pid() {
 
     unlink(temp_path);
 
-    exit(EXIT_FAILURE);
+    return -1;
   }
 
   if (get_config()->uid != 0) {
@@ -351,6 +351,8 @@ void save_pid() {
                 << " failed: " << strerror(error);
     }
   }
+
+  return 0;
 }
 } // namespace
 
@@ -2379,7 +2381,9 @@ int process_options(Config *config,
 
   tlsconf.tls_proto_mask = ssl::create_tls_proto_mask(tlsconf.tls_proto_list);
 
-  tlsconf.alpn_prefs = ssl::set_alpn_prefs(tlsconf.npn_list);
+  if (ssl::set_alpn_prefs(tlsconf.alpn_prefs, tlsconf.npn_list) != 0) {
+    return -1;
+  }
 
   tlsconf.bio_method = create_bio_method();
 

src/shrpx_ssl.cc

@@ -94,16 +94,14 @@ int verify_callback(int preverify_ok, X509_STORE_CTX *ctx) {
 }
 } // namespace
 
-// This function is meant be called from master process, hence the
-// call exit(3).
-std::vector<unsigned char>
-set_alpn_prefs(const std::vector<std::string> &protos) {
+int set_alpn_prefs(std::vector<unsigned char> &out,
+                   const std::vector<std::string> &protos) {
   size_t len = 0;
 
   for (const auto &proto : protos) {
     if (proto.size() > 255) {
       LOG(FATAL) << "Too long ALPN identifier: " << proto.size();
-      exit(EXIT_FAILURE);
+      return -1;
     }
 
     len += 1 + proto.size();
@@ -111,10 +109,10 @@ set_alpn_prefs(const std::vector<std::string> &protos) {
 
   if (len > (1 << 16) - 1) {
     LOG(FATAL) << "Too long ALPN identifier list: " << len;
-    exit(EXIT_FAILURE);
+    return -1;
   }
 
-  auto out = std::vector<unsigned char>(len);
+  out.resize(len);
   auto ptr = out.data();
 
   for (const auto &proto : protos) {
@@ -123,7 +121,7 @@ set_alpn_prefs(const std::vector<std::string> &protos) {
     ptr += proto.size();
   }
 
-  return out;
+  return 0;
 }
 
 namespace {

src/shrpx_ssl.h

@@ -181,8 +181,8 @@ bool check_http2_requirement(SSL *ssl);
 // passed to SSL_CTX_set_options().
 long int create_tls_proto_mask(const std::vector<std::string> &tls_proto_list);
 
-std::vector<unsigned char>
-set_alpn_prefs(const std::vector<std::string> &protos);
+int set_alpn_prefs(std::vector<unsigned char> &out,
+                   const std::vector<std::string> &protos);
 
 // Setups server side SSL_CTX.  This function inspects get_config()
 // and if upstream_no_tls is true, returns nullptr.  Otherwise