132 lines
5.6 KiB
C
132 lines
5.6 KiB
C
#include <fcntl.h>
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#include <pthread.h>
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#include <semaphore.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#define DEBUG 1 // turn of/off debug printing
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#define PROMPT ">> " // prompt for client UI
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#define MAXLINE 1024 // max length of line that can be typed for messages
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#define MAXNAME 256 // max length of user name for clients
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#define MAXPATH 1024 // max length filename paths
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#define MAXCLIENTS 256 // max number of clients accepted
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#define EOT 4 // ascii code of typical EOF character
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#define DEL 127 // ascii code of typical backspace key
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#define DEFAULT_PERMS S_IRUSR | S_IWUSR // default permissions for fifos
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#define ALARM_INTERVAL 1 // seconds between alarm rings and pings to clients
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#define DISCONNECT_SECS \
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5 // seconds before clients are dropped due to lack of contact
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// client_t: data on a client connected to the server
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typedef struct {
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char name[MAXPATH]; // name of the client
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int to_client_fd; // file descriptor to write to to send to client
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int to_server_fd; // file descriptor to read from to receive from client
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char to_client_fname[MAXPATH]; // name of file (FIFO) to write into send to
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// client
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char to_server_fname[MAXPATH]; // name of file (FIFO) to read from receive
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// from client
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int data_ready; // flag indicating a mesg_t can be read from to_server_fd
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int last_contact_time; // ADVANCED: server time at which last contact was
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// made with client
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} client_t;
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// server_t: data pertaining to server operations
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typedef struct {
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char server_name[MAXPATH]; // name of server which dictates file names for
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// joining and logging
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int join_fd; // file descriptor of join file/FIFO
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int join_ready; // flag indicating if a join is available
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int n_clients; // number of clients communicating with server
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client_t client[MAXCLIENTS]; // array of clients populated up to n_clients
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int time_sec; // ADVANCED: time in seconds since server started
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int log_fd; // ADVANCED: file descriptor for log
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sem_t *log_sem; // ADVANCED: posix semaphore to control who_t section of
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// log file
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} server_t;
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// join_t: structure for requests to join the chat room
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typedef struct {
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char name[MAXPATH]; // name of the client joining the server
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char to_client_fname[MAXPATH]; // name of file server writes to to send to
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// client
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char to_server_fname[MAXPATH]; // name of file client writes to to send to
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// server
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} join_t;
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// mesg_kind_t: Kinds of messages between server/client
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typedef enum {
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BL_MESG = 10, // normal messasge from client with name/body
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BL_JOINED = 20, // client joined the server, name only
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BL_DEPARTED = 30, // client leaving/left server normally, name only
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BL_SHUTDOWN =
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40, // server to client : server is shutting down, no name/body
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BL_DISCONNECTED = 50, // ADVANCED: client disconnected abnormally, name only
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BL_PING = 60, // ADVANCED: ping to ask or show liveness
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} mesg_kind_t;
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// mesg_t: struct for messages between server/client
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typedef struct {
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mesg_kind_t kind; // kind of message
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char name[MAXNAME]; // name of sending client or subject of event
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char body[MAXLINE]; // body text, possibly empty depending on kind
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} mesg_t;
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// who_t: data to write into server log for current clients (ADVANCED)
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typedef struct {
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int n_clients; // number of clients on server
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char names[MAXCLIENTS][MAXNAME]; // names of clients
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} who_t;
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// simpio_t: data structure to manage terminal input/output for clients
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typedef struct {
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char buf[MAXLINE]; // line of text to read
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char prompt[MAXNAME]; // prompt to be printed ahead of input
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int pos; // position in buf
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int line_ready; // flag determining if a line in buf is ready for
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// processing
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int end_of_input; // flag determining if end of input has been indicated
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FILE *infile; // FILE to read from for input, usually stdin
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FILE *outfile; // FILE to write to for output, usually stdout
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} simpio_t;
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// server.c
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client_t *server_get_client(server_t *server, int idx);
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void server_start(server_t *server, char *server_name, int perms);
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void server_shutdown(server_t *server);
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int server_add_client(server_t *server, join_t *join);
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int server_remove_client(server_t *server, int idx);
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int server_broadcast(server_t *server, mesg_t *mesg);
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void server_check_sources(server_t *server);
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int server_join_ready(server_t *server);
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int server_handle_join(server_t *server);
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int server_client_ready(server_t *server, int idx);
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int server_handle_client(server_t *server, int idx);
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void server_tick(server_t *server);
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void server_ping_clients(server_t *server);
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void server_remove_disconnected(server_t *server, int disconnect_secs);
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void server_write_who(server_t *server);
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void server_log_message(server_t *server, mesg_t *mesg);
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// simpio.c
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void simpio_noncanonical_terminal_mode();
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void simpio_reset_terminal_mode();
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void simpio_reset(simpio_t *simpio);
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void simpio_set_prompt(simpio_t *simpio, char *prompt);
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void simpio_get_char(simpio_t *simpio);
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void iprintf(simpio_t *simpio, char *fmt, ...);
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// util.c
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void check_fail(int condition, int perr, char *fmt, ...);
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void dbg_printf(char *fmt, ...);
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void pause_for(long nanos, int secs);
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