#include <ccan/oserver/oserver.h>
#include <ccan/read_write_all/read_write_all.h>
#include <ccan/opt/opt.h>
-#include <ccan/noerr/noerr.h>
+#include <ccan/tevent/tevent.h>
+#include <ccan/array_size/array_size.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
+#include <signal.h>
+#include <assert.h>
-bool oserver_serve(int fd)
+enum state {
+ SENDING_GREETING,
+ RECEIVING_USER_QUESTION,
+ AWAITING_A_SUBCLIENT,
+ SENDING_OTHER_QUESTION_PREFIX,
+ SENDING_OTHER_QUESTION,
+ RECEIVING_OTHER_ANSWER,
+ AWAITING_OUR_ORACLE,
+ SENDING_ANSWER_PREFIX,
+ SENDING_ANSWER,
+ FINISHED
+};
+
+static uint16_t state_flag_map[] = {
+ [SENDING_GREETING] = TEVENT_FD_WRITE,
+ [RECEIVING_USER_QUESTION] = TEVENT_FD_READ,
+ [AWAITING_A_SUBCLIENT] = 0,
+ [SENDING_OTHER_QUESTION_PREFIX] = TEVENT_FD_WRITE,
+ [SENDING_OTHER_QUESTION] = TEVENT_FD_WRITE,
+ [RECEIVING_OTHER_ANSWER] = TEVENT_FD_READ,
+ [AWAITING_OUR_ORACLE] = 0,
+ [SENDING_ANSWER_PREFIX] = TEVENT_FD_WRITE,
+ [SENDING_ANSWER] = TEVENT_FD_WRITE,
+ [FINISHED] = 0
+};
+
+struct client {
+ /* What are we doing today, brain? */
+ enum state state;
+ /* Our event info, and the file descriptor. */
+ struct tevent_fd *fde;
+ int fd;
+ /* The question we read from client. */
+ char *question;
+ /* The answer to the client. */
+ char *answer;
+ /* How many bytes of the reply we sent so far. */
+ size_t bytes_sent;
+ /* Our server. */
+ struct oserver *oserver;
+ /* Whose question this client is answering. */
+ struct client *subclient;
+ /* Who is answering our question. */
+ struct client *oracle;
+};
+
+struct oserver {
+ /* 5 clients should be enough for anybody! */
+ struct client *clients[5];
+ int fd;
+ struct tevent_fd *fde;
+};
+
+static ssize_t write_string(int fd, const char *str)
{
- char buf[1024];
- unsigned int i;
+ return write(fd, str, strlen(str));
+}
- for (i = 0; i < sizeof(buf)-1; i++) {
- if (read(fd, &buf[i], 1) != 1) {
- errno = EIO;
- return false;
- }
- if (buf[i] == '\n' || buf[i] == '\r')
- break;
- buf[i] = toupper(buf[i]);
+static ssize_t read_string(int fd, char **buf)
+{
+ ssize_t ret, len, maxlen;
+
+ len = strlen(*buf);
+ maxlen = talloc_array_length(*buf);
+
+ if (maxlen < len + 100) {
+ maxlen += 100;
+ *buf = talloc_realloc(NULL, *buf, char, maxlen);
}
- buf[i] = '\0';
- if (!write_all(fd, "Louder, like this: '",
- strlen("Louder, like this: '"))
- || !write_all(fd, buf, i)
- || !write_all(fd, "'\r\n", strlen("'\r\n")))
+ ret = read(fd, *buf + len, maxlen - len - 1);
+ if (ret >= 0)
+ (*buf)[len + ret] = '\0';
+ return ret;
+}
+
+static bool input_finished(const char *str)
+{
+ return strchr(str, '\n');
+}
+
+/* Update state, and set our READ/WRITE flags appropriately. */
+static void set_state(struct client *c, enum state state)
+{
+ c->state = state;
+ tevent_fd_set_flags(c->fde, state_flag_map[state]);
+}
+
+/* Returns false on error, increments state on finishing string. */
+static bool send_string(struct client *c, const char *str)
+{
+ ssize_t len = write_string(c->fd, str + c->bytes_sent);
+ if (len < 0)
return false;
+ c->bytes_sent += len;
+ if (c->bytes_sent == strlen(str)) {
+ c->bytes_sent = 0;
+ set_state(c, c->state+1);
+ }
return true;
}
-int oserver_setup(unsigned short port)
+static bool get_subclient(struct client *me)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
+ struct client *c = me->oserver->clients[i];
+ if (!c || c == me)
+ continue;
+ if (c->oracle == NULL && input_finished(c->question)) {
+ me->subclient = c;
+ c->oracle = me;
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool get_oracle(struct client *me)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
+ struct client *c = me->oserver->clients[i];
+ if (!c || c == me)
+ continue;
+ if (c->subclient == NULL && input_finished(c->question)) {
+ me->oracle = c;
+ c->subclient = me;
+ return true;
+ }
+ }
+ return false;
+}
+
+static void service_client(struct tevent_context *ev,
+ struct tevent_fd *fde, uint16_t flags, void *_c)
+{
+ struct client *c = _c;
+ ssize_t len;
+
+ switch (c->state) {
+ case SENDING_GREETING:
+ if (!send_string(c, "Welcome. Please ask your question.\n"))
+ goto fail;
+ break;
+ case RECEIVING_USER_QUESTION:
+ len = read_string(c->fd, &c->question);
+ if (len <= 0)
+ goto fail;
+ if (input_finished(c->question)) {
+ /* Look for someone to be oracle to. */
+ if (get_subclient(c)) {
+ set_state(c, SENDING_OTHER_QUESTION_PREFIX);
+ } else {
+ /* We sit here until someone find_oracles us */
+ set_state(c, AWAITING_A_SUBCLIENT);
+ }
+
+ /* Look for an oracle for ourselves. */
+ if (get_oracle(c)) {
+ assert(c->oracle->state
+ == AWAITING_A_SUBCLIENT);
+ set_state(c->oracle,
+ SENDING_OTHER_QUESTION_PREFIX);
+ }
+ }
+ break;
+ case SENDING_OTHER_QUESTION_PREFIX:
+ if (!send_string(c, "While the Oracle ponders,"
+ " please answer the following question:\n"))
+ goto fail;
+ break;
+ case SENDING_OTHER_QUESTION:
+ if (!send_string(c, c->subclient->question))
+ goto fail;
+ break;
+ case RECEIVING_OTHER_ANSWER:
+ len = read_string(c->fd, &c->subclient->answer);
+ if (len <= 0)
+ goto fail;
+ if (input_finished(c->subclient->answer)) {
+ /* Did our oracle answer for us already? */
+ if (input_finished(c->answer))
+ set_state(c, SENDING_ANSWER_PREFIX);
+ else
+ set_state(c, AWAITING_OUR_ORACLE);
+
+ /* If they were waiting for an answer, move them. */
+ if (c->subclient->state == AWAITING_OUR_ORACLE)
+ set_state(c->subclient, SENDING_ANSWER_PREFIX);
+ }
+ break;
+ case SENDING_ANSWER_PREFIX:
+ if (!send_string(c, "The Oracle spake thus:\n"))
+ goto fail;
+ break;
+ case SENDING_ANSWER:
+ if (!send_string(c, c->answer))
+ goto fail;
+ break;
+ default:
+ goto fail;
+ }
+
+ if (c->state != FINISHED)
+ return;
+
+fail:
+ talloc_free(c);
+}
+
+static int cleanup_client(struct client *client)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(client->oserver->clients); i++) {
+ if (client->oserver->clients[i] == client) {
+ client->oserver->clients[i] = NULL;
+ tevent_fd_set_flags(client->oserver->fde,
+ TEVENT_FD_READ);
+ return 0;
+ }
+ }
+ abort();
+}
+
+static void add_client(struct tevent_context *ev,
+ struct tevent_fd *fde, uint16_t flags, void *_oserver)
+{
+ struct oserver *oserver = _oserver;
+ struct client *client;
+ unsigned int i;
+
+ client = talloc(oserver, struct client);
+ client->fd = accept(oserver->fd, NULL, 0);
+ if (client->fd < 0)
+ err(1, "Accepting client connection");
+
+ client->state = SENDING_GREETING;
+ client->bytes_sent = 0;
+ client->question = talloc_strdup(client, "");
+ client->oserver = oserver;
+ client->oracle = NULL;
+ client->subclient = NULL;
+ client->answer = talloc_strdup(client, "");
+ client->fde = tevent_add_fd(ev, client, client->fd,
+ state_flag_map[client->state],
+ service_client, client);
+ tevent_fd_set_auto_close(client->fde);
+
+ /* Find empty slot in array for this client. */
+ for (i = 0; oserver->clients[i]; i++);
+ oserver->clients[i] = client;
+ talloc_set_destructor(client, cleanup_client);
+
+ /* Full? Stop listening... */
+ if (i == ARRAY_SIZE(oserver->clients)-1)
+ tevent_fd_set_flags(oserver->fde, 0);
+}
+
+static void clear_clients(struct oserver *oserver)
+{
+ memset(oserver->clients, 0,
+ ARRAY_SIZE(oserver->clients) * sizeof(oserver->clients[0]));
+}
+
+static int destroy_oserver(struct oserver *oserver)
{
- int sockfd;
+ close(oserver->fd);
+ return 0;
+}
+
+struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
+{
+ struct oserver *oserver;
int one = 1;
union {
struct sockaddr addr;
struct sockaddr_in in;
} u;
- sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
- if (sockfd < 0)
- return -1;
+ oserver = talloc(ev, struct oserver);
+ clear_clients(oserver);
+ oserver->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+ if (oserver->fd < 0) {
+ talloc_free(oserver);
+ return NULL;
+ }
+
+ talloc_set_destructor(oserver, destroy_oserver);
- if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
+ if (setsockopt(oserver->fd, SOL_SOCKET, SO_REUSEADDR,
+ &one, sizeof(one)))
warn("Setting socket reuse");
u.in.sin_family = AF_INET;
u.in.sin_port = htons(port);
u.in.sin_addr.s_addr = INADDR_ANY;
- if (bind(sockfd, &u.addr, sizeof(u.in)) == -1) {
- close_noerr(sockfd);
- return -1;
+ if (bind(oserver->fd, &u.addr, sizeof(u.in)) == -1) {
+ talloc_free(oserver);
+ return NULL;
}
- if (listen(sockfd, 0) != 0) {
- close_noerr(sockfd);
- return -1;
+ if (listen(oserver->fd, 0) != 0) {
+ talloc_free(oserver);
+ return NULL;
}
- return sockfd;
+
+ oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
+ TEVENT_FD_READ, add_client, oserver);
+ if (!oserver->fde) {
+ talloc_free(oserver);
+ return NULL;
+ }
+
+ /* Don't kill us if client dies. */
+ signal(SIGPIPE, SIG_IGN);
+
+ return oserver;
}
projects / ccan-lca-2011.git / blobdiff