Add simple HTTP server

Makefile

@@ -1,2 +1,2 @@
 camera_stream: *.c *.h
-	gcc -g -o camera_stream *.c
+	gcc -g -lpthread -o camera_stream *.c

http.c

@@ -0,0 +1,86 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+
+#include "http.h"
+
+#define BUFSIZE 256
+
+int http_listen(int listen_port, int maxcons)
+{
+  struct sockaddr_in server = {0};
+  int listenfd = -1;
+
+  // getaddrinfo for host
+  server.sin_family = AF_INET;
+  server.sin_addr.s_addr = INADDR_ANY;
+  server.sin_port = htons(listen_port);
+
+  listenfd = socket(AF_INET, SOCK_STREAM, 0);
+  if (listenfd < 0) {
+    return -1;
+  }
+
+  if (bind(listenfd, (struct sockaddr *)&server, sizeof(server)) < 0) {
+    goto error;
+  }
+
+  if (listen(listenfd, maxcons) < 0) {
+    goto error;
+  }
+
+  return listenfd;
+error:
+  if (listenfd >= 0)
+    close(listenfd);
+  return -1;
+}
+
+void http_process(int fd, struct sockaddr_in *addr)
+{
+  FILE *stream = fdopen(fd, "r+");
+  if (!stream) {
+    return;
+  }
+
+  char line[BUFSIZE];
+  fgets(line, BUFSIZE, stream);
+
+  fprintf(stream, "HTTP/1.1 200 OK\n");
+  fprintf(stream, "Content-Type: text/plain\n");
+  fprintf(stream, "\r\n");
+  fprintf(stream, "Text.\n");
+  fflush(stream);
+  fclose(stream);
+}
+
+int http_worker(int listenfd)
+{
+  while (1) {
+    struct sockaddr_in addr;
+    int addrlen = sizeof(addr);
+    int ret = accept(listenfd, (struct sockaddr *)&addr, &addrlen);
+    if (ret < 0) {
+      return -1;
+    }
+
+    http_process(ret, &addr);
+    close(ret);
+  }
+
+  return -1;
+}
+
+int http_worker_threads(int listenfd, int nthreads)
+{
+  while (nthreads-- > 0) {
+    pthread_t thread;
+    pthread_create(&thread, NULL, (void *(*)(void*))http_worker, (void*)listenfd);
+  }
+
+  return 0;
+}

http.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include "v4l2.h"
+
+int http_listen(int listen_port, int maxcons);
+int http_worker(int listenfd);
+int http_worker_threads(int listenfd, int nthreads);

main.c

@@ -3,6 +3,7 @@
 #include "device.h"
 #include "links.h"
 #include "v4l2.h"
+#include "http.h"
 
 int camera_width = 1920;
 int camera_height = 1080;
@@ -103,6 +104,11 @@ int main(int argc, char *argv[])
   //   return -1;
   // }
 
+  int httpfd = http_listen(9090, 5);
+  if (httpfd >= 0) {
+    http_worker_threads(httpfd, 8);
+  }
+
   bool running = false;
   links_loop(links, &running);
 

v4l2.h

@@ -11,6 +11,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <unistd.h>
+#include <pthread.h>
 
 #include <sys/ioctl.h>
 #include <sys/mman.h>