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pi_server.c
219 lines (157 loc) · 5.02 KB
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pi_server.c
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/*
* Raspberry Pi Server
*/
#include "pi_server.h"
//Constants
static const int LISTEN_PORT_NUM = 55000;
static const int QUEUE_LENGTH = 1024;
static const int MAX_LENGTH = 8192;
static const int MAX_BUF = 8192;
//Variables
static Queue q;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static bool is_init = false;
/* Adds a message to the message queue. */
void add_message(char * message, int message_length) {
pthread_mutex_lock(&mutex);
if (!is_init || !message || message_length <= 0)
return;
string_node * snode = alloc_string_node(message, message_length);
add_queue(&q, &(snode->node));
pthread_mutex_unlock(&mutex);
}
/* main function */
void * run_server_args(void * port_number) {
int port;
if (!port_number)
port = LISTEN_PORT_NUM;
else
port = *(int *) port_number;
if (port <= 1024)
port = LISTEN_PORT_NUM;
init_queue(&q);
struct sockaddr sock_addr;
int listen_fd = init(port, &sock_addr);
is_init = true;
wait_for_listen(listen_fd, &sock_addr);
return NULL;
}
/* main function, no arguments, uses default port number. */
void * run_server() {
int port_number = LISTEN_PORT_NUM;
return run_server_args(&port_number);
}
/* Getter for the is_init bool. Indicates server is setup and listening */
bool is_server_init() {
return is_init;
}
/*
* Set up threadpool and listening socket for normal listening server.
* Set up threadpool, commandcenter, and listening socket.
*/
static int init(int portnum, struct sockaddr * sock_addr) {
char strportnum[10];
sprintf(strportnum, "%d", portnum);
int listening_fd = -1;
struct addrinfo * it;
//Setup and run getaddrinfo
struct addrinfo hints, * ai;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_flags = AI_PASSIVE;
hints.ai_socktype = SOCK_STREAM;
Getaddrinfo(NULL, strportnum, &hints, &ai);
//iterate over results of getaddrinfo and bind ipvX address
for (it = ai; it != NULL; it = it->ai_next) {
//check if this addrinfo has the correct family
if (it->ai_family == AF_INET) {
//begin listening
sock_addr = it->ai_addr;
listening_fd = init_listen(sock_addr);
}
}
freeaddrinfo(ai);
return listening_fd;
}
/* Helper function that initializes the listening socket for ipv4 addresses. */
static int init_listen(struct sockaddr * sock_addr) {
//Set vars for sockopt depending on IP family
int optname = SO_REUSEADDR;
int level = SOL_SOCKET;
int listen_fd = Socket(AF_INET, SOCK_STREAM, 0);
Setsockopt(listen_fd, level, optname);
Bind(listen_fd, sock_addr, sizeof(struct sockaddr_in));
Listen(listen_fd, QUEUE_LENGTH);
return listen_fd;
}
/* Wait for a new connection. Takes a wrapper struct of sockfd and sockaddr_in as argument */
static void wait_for_listen(int sockfd, struct sockaddr * addr) {
unsigned int addrlen = sizeof(addr);
int connected_fd;
// Infinite loop for constant acceptance
while(true){
connected_fd = Accept(sockfd, addr, &addrlen);
run(connected_fd);
}
Close(sockfd);
}
/*
* Receives requests and places the messages in a queue.
*/
static void run(int fd) {
char buf[MAX_LENGTH], method[MAX_LENGTH], uri[MAX_LENGTH], version[MAX_LENGTH], error[MAX_LENGTH];
char * args = NULL;
//clear variables to prevent corruption
memset(error, '\0', MAX_LENGTH);
memset(uri, '\0', MAX_LENGTH);
memset(buf, '\0', MAX_LENGTH);
memset(version, '\0', MAX_LENGTH);
memset(method, '\0', MAX_LENGTH);
// Parse and perform requests if we haven't hit timeout and if the headers are still valid
while (read(fd, buf, MAX_LENGTH) > 0) {
sscanf(buf, "%s %s %s", method, uri, version);
//Check for non GET method call
if (strncasecmp(method, "GET", 3)) {
snprintf(error, sizeof(error), "501 error: %s not supported The server does not support the method provided %s", method, version);
write(fd, error, sizeof(error));
Close(fd);
return;
}
//check if version is HTTP 1.0, if so, break.
if (strcmp(version, "HTTP/1.0") == 0) {
fprintf(stderr, "NON HTTP 1.0 MESSAGE RECEIVED\n");
break;
}
if ((args = strstr(uri, "/get_messages")))
send_messages(fd, version);
//clear variables to prevent corruption
memset(error, '\0', MAX_LENGTH);
memset(uri, '\0', MAX_LENGTH);
memset(buf, '\0', MAX_LENGTH);
memset(version, '\0', MAX_LENGTH);
memset(method, '\0', MAX_LENGTH);
}
Close(fd);
}
static void send_messages(int fd, char * version) {
char buf[MAX_BUF];
char msg[MAX_LENGTH];
int message_size = 0;
QNode * qnode;
string_node * snode;
pthread_mutex_lock(&mutex);
while(!is_empty(&q)) {
qnode = remove_queue(&q);
snode = QUEUE_ENTRY(qnode, string_node, node);
strncat(msg, snode->str, snode->str_length);
message_size += snode->str_length;
free_string_node(snode);
}
// Send response headers to client
sprintf(buf, "%s 200 OK\r\n", version);
sprintf(buf, "%sServer: Pi Web Server\r\n", buf);
sprintf(buf, "%sContent-length: %d\r\n", buf, message_size);
sprintf(buf, "%sContent-type: text/html\r\n\r\n", buf);
write(fd, buf, sizeof(buf));
write(fd, msg, sizeof(msg));
pthread_mutex_unlock(&mutex);
}