add an alarm, so we don't wait forever for input (#23482)

wait another second
add an upper bound on how much stuff we'll keep in memory

1 files changed, 23 insertions, 11 deletions

diff --git a/src/minilogd.c b/src/minilogd.c
index aba5e7c5..90bce3f8 100644
--- a/src/minilogd.c
+++ b/src/minilogd.c
@@ -25,6 +25,14 @@ static int buflines=0;
 
 int debug;
 
+int recvsock;
+
+void alarm_handler(int x) {
+	alarm(0);
+	close(recvsock);
+	recvsock = -1;
+}
+
 void freeBuffer() {
    struct sockaddr_un addr;
    int sock;
@@ -34,7 +42,7 @@ void freeBuffer() {
    addr.sun_family = AF_LOCAL;
    strncpy(addr.sun_path,_PATH_LOG,sizeof(addr.sun_path)-1);
    /* wait for klogd to hit syslog */
-   sleep(1);
+   sleep(2);
    sock = socket(AF_LOCAL, SOCK_DGRAM,0);
    conn=connect(sock,(struct sockaddr *) &addr,sizeof(addr));
    while (x<buflines) {
@@ -61,7 +69,7 @@ void cleanup(int exitcode) {
 
 void runDaemon(int sock) {
    struct sockaddr_un addr;
-   int x,len,addrlen,recvsock,done=0;
+   int x,len,addrlen,done=0;
    char *message;
    struct stat s1,s2;
    struct pollfd pfds;
@@ -94,19 +102,23 @@ void runDaemon(int sock) {
       if ( (x>0) && pfds.revents & (POLLIN | POLLPRI)) {
 	 message = calloc(8192,sizeof(char));
 	 recvsock = accept(sock,(struct sockaddr *) &addr, &addrlen);
+	 alarm(2);
+	 signal(SIGALRM, alarm_handler);
 	 len = read(recvsock,message,8192);
-	 if (buffer)
-	   buffer = realloc(buffer,(buflines+1)*sizeof(char *));
-	 else
-	   buffer = malloc(sizeof(char *));
+	 alarm(0);
+	 close(recvsock);
 	 if (len>0) {
-	     message[strlen(message)]='\n';
-	    buffer[buflines]=message;
-	    buflines++;
-	    close(recvsock);
+		 if (buflines < 200000) {
+			 if (buffer)
+			   buffer = realloc(buffer,(buflines+1)*sizeof(char *));
+			 else
+			   buffer = malloc(sizeof(char *));
+			 message[strlen(message)]='\n';
+			 buffer[buflines]=message;
+			 buflines++;
+		 }
 	 }
 	 else {
-	    close(recvsock);
 	    recvsock=-1;
 	 }
       }