CSE320/hw5/tests/script_tester.c
2022-04-16 17:19:19 -04:00

643 lines
22 KiB
C

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/time.h>
#include "pbx.h"
#include "server.h"
#include "__test_includes.h"
#include "debug.h"
#define NUM_STATES 7
#define NUM_COMMANDS 5
#define DELAY_COMMAND (NUM_COMMANDS-1)
/*
* Table of expected next states.
* Each entry is a bitmap that specifies a set of possible next states, given
* the current state and the last command that was issued.
*
* An issue that this tester has to handle is that commands to the server can
* "cross in transit" asynchronous state-change notifications coming back from the server.
* If we are currently in the TU_ON_HOOK state and we send a TU_PICKUP_CMD, it might
* be that the TU_PICKUP_CMD crosses in transit a TU_RINGING notification being sent
* back to us. What we will see is a next-state notification of TU_RINGING, rather
* than the TU_DIAL_TONE notification that we would otherwise expect.
*
* To handle this, there are two classes of expected states encoded in each entry of
* the table. The "normal case" encodes a TU_STATE s as the bit value 1<<s, and it
* indicates a state that we would expect to see if there were no "crossing in transit".
* The "abnormal case" encodes additional states that we might see when messages
* cross in transit. These are encoded as 1<<(s+RESYNC), where RESYNC is larger than
* any TU_STATE value. When we receive a state notification, it is checked against
* the expected state bitmap. If we find that state among the "normal case" states,
* then nothing special happens and we proceed on to selecting the next command to send.
* On the other hand, if we find that state among the "abnormal case" states, then
* a "resync" flag is set and we do not immediately select a new command to send.
* Instead, we assume that what we have just received is an asynchronous state-change
* notification that crossed in transit our last command, and that the response to
* our last command is still forthcoming. In this situation, we redetermine the set
* of expected events based on the new state, but the last command that we sent.
* When we finally do receive a "normal case" response, then the resynchronization is
* over and we proceed to send another command.
*
* A deficiency in the current implementation is that there ought to be a timeout after
* which we declare failure if a resynchronization has not completed within a short
* period of time.
*
* Another deficiency at the moment is that the tester tests that "bad things don't happen",
* but it doesn't really check that "good things do happen" (e.g. that calls get connected).
*
* One other deficiency is in the treatment of delays. When the action chosen from a state
* is to delay, the delays will continue until a non-delay action is chosen, without reading
* any notifications from the server until the delay period is over. It would be better if
* the arrival of notifications from the server was checked after each basic delay, but that
* would further complicate the program and it has not been implemented at this time.
*/
#define RESYNC NUM_STATES
int next_states[NUM_STATES][NUM_COMMANDS] = {
[TU_ON_HOOK] {
1<<TU_DIAL_TONE | 1<<(TU_RINGING+RESYNC) | 1<<(TU_ON_HOOK+RESYNC), // TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_RINGING+RESYNC), // TU_HANGUP_CMD
1<<TU_ON_HOOK | 1<<(TU_RINGING+RESYNC), // TU_DIAL_CMD
1<<TU_ON_HOOK | 1<<(TU_RINGING+RESYNC), // TU_CHAT_CMD
1<<(TU_ON_HOOK+RESYNC) | 1<<(TU_RINGING+RESYNC) // DELAY
},
[TU_RINGING] {
1<<TU_CONNECTED | 1<<(TU_ON_HOOK+RESYNC) | 1<<(TU_RINGING+RESYNC), // TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_RINGING+RESYNC), // TU_HANGUP_CMD
1<<TU_RINGING | 1<<(TU_ON_HOOK+RESYNC), // TU_DIAL_CMD
1<<TU_RINGING | 1<<(TU_ON_HOOK+RESYNC), // TU_CHAT_CMD
1<<(TU_RINGING+RESYNC) | 1<<(TU_ON_HOOK+RESYNC) // DELAY
},
[TU_DIAL_TONE] {
1<<TU_DIAL_TONE, // TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_DIAL_TONE+RESYNC), // TU_HANGUP_CMD
1<<TU_RING_BACK | 1<<TU_BUSY_SIGNAL | 1<<TU_ERROR
| 1<<(TU_DIAL_TONE+RESYNC), // TU_DIAL_CMD
1<<TU_DIAL_TONE, // TU_CHAT_CMD
1<<(TU_DIAL_TONE+RESYNC) // DELAY
},
[TU_RING_BACK] {
1<<TU_RING_BACK | 1<<(TU_CONNECTED+RESYNC) | 1<<(TU_DIAL_TONE+RESYNC),// TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_CONNECTED+RESYNC) | 1<<(TU_DIAL_TONE+RESYNC)
| 1<<(TU_RING_BACK+RESYNC), // TU_HANGUP_CMD
1<<TU_RING_BACK | 1<<(TU_CONNECTED+RESYNC) | 1<<(TU_DIAL_TONE+RESYNC),// TU_DIAL_CMD
1<<TU_RING_BACK | 1<<(TU_CONNECTED+RESYNC) | 1<<(TU_DIAL_TONE+RESYNC),// TU_CHAT_CMD
1<<(TU_RING_BACK+RESYNC) | 1<<(TU_CONNECTED+RESYNC) | 1<<(TU_DIAL_TONE+RESYNC) // DELAY
},
[TU_BUSY_SIGNAL] {
1<<TU_BUSY_SIGNAL, // TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_BUSY_SIGNAL+RESYNC), // TU_HANGUP_CMD
1<<TU_BUSY_SIGNAL, // TU_DIAL_CMD
1<<TU_BUSY_SIGNAL, // TU_CHAT_CMD
1<<(TU_BUSY_SIGNAL+RESYNC) // DELAY
},
[TU_CONNECTED] {
1<<TU_CONNECTED | 1<<(TU_DIAL_TONE+RESYNC) | 1<<(TU_CONNECTED+RESYNC),// TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_DIAL_TONE+RESYNC) | 1<<(TU_CONNECTED+RESYNC), // TU_HANGUP_CMD
1<<TU_CONNECTED | 1<<(TU_DIAL_TONE+RESYNC), // TU_DIAL_CMD
1<<TU_CONNECTED | 1<<(TU_DIAL_TONE+RESYNC), // TU_CHAT_CMD
1<<(TU_CONNECTED+RESYNC) | 1<<(TU_DIAL_TONE+RESYNC) // DELAY
},
[TU_ERROR] {
1<<TU_ERROR, // TU_PICKUP_CMD
1<<TU_ON_HOOK | 1<<(TU_ERROR+RESYNC), // TU_HANGUP_CMD
1<<TU_ERROR, // TU_DIAL_CMD
1<<TU_ERROR, // TU_CHAT_CMD
1<<(TU_ERROR+RESYNC) // DELAY
}
};
/*
* Structure that records the state of a single TU under test.
*/
typedef struct tu {
/* File descriptor for input from server connection, or 0 if not connected. */
int infd;
/* File descriptor for output to server connection, or 0 if not connected. */
int outfd;
/* Input stream from the server. */
FILE *in;
/* Output stream to the server. */
FILE *out;
/* Extension number we have been assigned by the server. */
int extension;
/* Extension to which we are connnected. */
int peer;
/* The current state of the TU simulated by the tester. */
TU_STATE current_state;
/*
* A bitmap that specifies the set of next states we expect, as described above.
* A transition to a state not in this set results in a test failure.
*/
int expected_states;
/*
* Flag that indicates whether we are currently resynchronizing, as a result of
* due to messages that "crossed in transit".
*/
int resync;
/*
* The last command sent to the server. This is used during resynchronization,
* to determine a new set of expected states as each successive asynchronous
* notification is received.
*/
TU_COMMAND last_command;
} TU;
/*
* Table giving the states of all TUs under test.
*/
#define MAX_TUS 20
TU tus[MAX_TUS];
#define TU_ID(tu) ((tu) - &tus[0])
/*
* "Meta-commands" for the test script.
* These are not actual TU commands, but rather specify other actions to
* be performed during a test script.
*/
#if 0
#define TU_NO_CMD 100
#define TU_CONNECT_CMD 101
#define TU_DISCONNECT_CMD 102
#define TU_AWAIT_CMD 103 // Await a specified TU state (e.g. TU_RINGING)
#define TU_DELAY_CMD 104 // Timeout specifies time delay
#endif
/*
* Sample test script.
* Later these will be provided by individual Criterion tests.
*/
#if 0
TEST_STEP sample_test_script[] = {
// ID, COMMAND, ID_TO_DIAL, RESPONSE, TIMEOUT
{ 0, TU_CONNECT_CMD, -1, TU_ON_HOOK, { 1, 0 }},
{ 1, TU_CONNECT_CMD, -1, TU_ON_HOOK, { 1, 0 }},
{ 1, TU_PICKUP_CMD, -1, TU_DIAL_TONE, { 1, 0 }},
{ 1, TU_DIAL_CMD, 0, TU_RING_BACK, { 1, 0 }},
{ 0, TU_AWAIT_CMD, -1, TU_RINGING, { 1, 0 }},
{ 0, TU_PICKUP_CMD, -1, TU_CONNECTED, { 1, 0 }},
{ 0, TU_DISCONNECT_CMD, -1, -1, { 1, 0 }},
{ 1, TU_DISCONNECT_CMD, -1, -1, { 1, 0 }},
{ -1, -1, -1, -1, { 0, 0 }}
};
#endif
/* Prototypes for functions that appear below. */
static void test(FILE *in, FILE *out, int cmds);
static int choose_action(void);
static TU_STATE parse_message(char *msg, char **arg);
static char *unparse_state_set(int set);
static void trim_eol(char *msg);
static char *timestamp(void);
static int connect_command(TU *tu, int port);
static void disconnect_command(TU *tu);
static int connect_to_server(struct in_addr *addr, int port);
static int read_responses(TU *tu, TU_STATE exp, struct timeval tv);
/*
* Temporary main until this is fleshed out.
* Then it will be hooked to Criterion.
*/
#if 0
int main(int argc, char *argv[]) {
if(run_test_script(sample_test_script, SERVER_PORT) == -1) {
debug("Script failed");
return EXIT_FAILURE;
} else {
debug("Script succeeded");
return EXIT_SUCCESS;
}
}
#endif
static void alert(int sig) {
fprintf(stderr, "Unexpected signal: %d\n", sig);
abort();
}
/*
* Run a test script provided as a parameter.
* Returns 0 on success, -1 on failure.
*/
int run_test_script(char *name, TEST_STEP *scr, int port) {
fprintf(stderr, "Running test %s\n", name);
signal(SIGPIPE, alert);
signal(SIGSEGV, alert);
signal(SIGHUP, alert);
signal(SIGINT, alert);
TEST_STEP *ts = scr;
struct timespec tms = {0};
while(ts->id != -1) {
if(ts->id >= MAX_TUS) {
fprintf(stderr, "Script error: TU ID %d too large (>= %d)\n", ts->id, MAX_TUS);
return -1;
}
int cmd = ts->command;
int ext = -1;
TU *tu = &tus[ts->id];
// First, deal with performing any explicit action.
switch(ts->command) {
// Meta-commands
case TU_NO_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) TU_NO_CMD\n", timestamp(), TU_ID(tu), ts - scr);
break;
case TU_CONNECT_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) TU_CONNECT_CMD\n", timestamp(), TU_ID(tu), ts - scr);
if(tu->infd) {
fprintf(stderr, "%s: [%ld] Test error: already connected\n",
timestamp(), TU_ID(tu));
return -1;
}
// Otherwise connect to server and update state.
if(connect_command(tu, port) == -1)
return -1;
break;
case TU_DISCONNECT_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) TU_DISCONNECT_CMD\n", timestamp(), TU_ID(tu), ts - scr);
if(!tu->infd) {
fprintf(stderr, "%s: [%ld] Test error: not connected\n", timestamp(), TU_ID(tu));
return -1;
}
disconnect_command(tu);
break;
case TU_DELAY_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) TU_DELAY_CMD\n", timestamp(), TU_ID(tu), ts - scr);
// Pause for the specified amount of time.
tms.tv_sec = ts->timeout.tv_sec;
tms.tv_nsec = ts->timeout.tv_usec * 1000l;
nanosleep(&tms, NULL);
break;
case TU_AWAIT_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) TU_AWAIT_CMD\n", timestamp(), TU_ID(tu), ts - scr);
// Process incoming messages until specified state seen
// or timeout occurs.
break;
// Real commands
case TU_PICKUP_CMD:
case TU_HANGUP_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) %s\n",
timestamp(), TU_ID(tu), ts - scr, tu_command_names[cmd]);
fprintf(tu->out, "%s%s", tu_command_names[cmd], EOL);
fflush(tu->out);
break;
case TU_DIAL_CMD:
ext = tus[ts->id_to_dial].extension;
fprintf(stderr, "%s: [%ld] (step #%ld) %s extension %d (id %d)\n",
timestamp(), TU_ID(tu), ts - scr, tu_command_names[cmd], ext, ts->id_to_dial);
fprintf(tu->out, "%s %d%s", tu_command_names[cmd], ext, EOL);
fflush(tu->out);
break;
case TU_CHAT_CMD:
fprintf(stderr, "%s: [%ld] (step #%ld) %s\n",
timestamp(), TU_ID(tu), ts - scr, tu_command_names[cmd]);
fprintf(tu->out, "%s%s", tu_command_names[cmd], EOL);
fflush(tu->out);
break;
// Unknown command
default:
fprintf(stderr, "%s: [%ld] (step #%ld) Test error: unknown command (%d)\n",
timestamp(), TU_ID(tu), ts - scr, cmd);
return -1;
}
if(cmd <= TU_CHAT_CMD) {
tu->last_command = cmd;
tu->expected_states = next_states[tu->current_state][cmd];
} else if(cmd == TU_CONNECT_CMD) {
// This is to get the right set of expected commands on initial connect,
// when no previous command has actually been sent.
tu->last_command = TU_HANGUP_CMD;
tu->expected_states = next_states[tu->current_state][TU_HANGUP_CMD];
} else if(cmd == TU_DISCONNECT_CMD) {
fprintf(stderr, "%s: [%ld] Disconnected, now expecting EOF\n", timestamp(), TU_ID(tu));
tu->last_command = cmd;
tu->expected_states = ~0; // We allow anything to drain pending notifications.
} else {
// For pseudo-commands, just recalculate the expected states based on
// the last real command.
tu->expected_states = next_states[tu->current_state][tu->last_command];
}
// Next, read responses while keeping track of timeout.
// If expected response seen, go to next step.
// If unexpected response seen, fail.
// If timeout occurs, shutdown the connection so that read will fail.
if(tu->infd && read_responses(tu, ts->response, ts->timeout) == -1)
return -1;
// Advance script to next test step.
ts++;
}
return 0;
}
/*
* Connect a specified TU to the server.
* Returns 0 on success, -1 on error.
*/
static int connect_command(TU *tu, int port) {
char *hostname = "localhost";
struct in_addr sa;
struct hostent *he;
int sfd;
// Connect to server on specified port and set sfd.
if((he = gethostbyname(hostname)) == NULL) {
herror("gethostbyname");
return -1;
}
memcpy(&sa, he->h_addr, sizeof(sa));
if((sfd = connect_to_server(&sa, port)) == -1) {
fprintf(stdout, "%s [%ld]: Failed to connect to server %s:%d\n",
timestamp(), TU_ID(tu), hostname, port);
return -1;
}
struct sockaddr_in s;
socklen_t sl = sizeof(s);
getsockname(sfd, (struct sockaddr *)&s, &sl);
port = s.sin_port;
fprintf(stdout, "%s: [%ld] Connected to server %s:%d\n",
timestamp(), TU_ID(tu), hostname, port);
// Save file descriptor and set up streams and initial test state.
memset(tu, 0, sizeof(*tu));
tu->infd = sfd;
tu->outfd = dup(sfd); // So they can be closed independently.
tu->in = fdopen(tu->infd, "r");
tu->out = fdopen(tu->outfd, "w");
// Initial expected state notification is TU_ON_HOOK
tu->expected_states = 1<<TU_ON_HOOK;
// Set initial last command to TU_HANGUP so that updating expected states
// works properly.
tu->last_command = TU_HANGUP_CMD;
return 0;
}
/*
* Disconnect a specified TU from the server.
*/
static void disconnect_command(TU *tu) {
if(tu->outfd) {
shutdown(tu->outfd, SHUT_WR); // This lets us see if the server notices.
tu->outfd = 0;
}
if(tu->out) {
fclose(tu->out);
tu->out = NULL;
}
// Closing the input should go where we detect EOF.
#if 0
if(tu->in) {
fclose(tu->in);
tu->in = NULL;
}
#endif
}
/* There isn't really a maximum message length, but this is just a test driver... */
#define MAX_MESSAGE_LEN 256
static struct timeval current_timeout;
static TU *tu_to_read;
static void alarm_handler(int sig) {
fprintf(stderr, "%s: [%ld] Timeout (%ld, %ld)\n", timestamp(), TU_ID(tu_to_read),
current_timeout.tv_sec, current_timeout.tv_usec);
shutdown(tu_to_read->infd, SHUT_RD); // Force return from fgets
}
/*
* Read responses from the server for a specified TU until an expected state is reached.
*/
static int read_responses(TU *tu, TU_STATE exp, struct timeval tv) {
TU_STATE new;
char msg[MAX_MESSAGE_LEN];
char *arg;
int ret = 0;
fprintf(stderr, "%s: [%ld] Read responses until %s\n",
timestamp(), TU_ID(tu), exp == -1 ? "EOF" : tu_state_names[exp]);
tu_to_read = tu;
struct itimerval itv = {0};
struct sigaction sa = {0}, oa;
sa.sa_handler = alarm_handler;
sa.sa_flags = SA_RESTART;
itv.it_value = tv;
current_timeout = tv;
sigaction(SIGALRM, &sa, &oa);
setitimer(ITIMER_REAL, &itv, NULL);
memset(&itv, 0, sizeof(itv));
itv.it_value = tv;
setitimer(ITIMER_REAL, &itv, NULL);
do {
fprintf(stderr, "%s: [%ld] Expecting: %s\n", timestamp(), TU_ID(tu),
unparse_state_set(tu->expected_states));
if(fgets(msg, MAX_MESSAGE_LEN, tu->in) == NULL) {
fprintf(stderr, "%s: [%ld] EOF reading message from server\n", timestamp(), TU_ID(tu));
fclose(tu->in);
tu->infd = 0;
if(tu->resync) {
fprintf(stderr, "%s: [%ld] Premature disconnection during resync\n",
timestamp(), TU_ID(tu));
ret = -1;
goto disarm;
} else {
if(tu->expected_states == ~0) {
fprintf(stderr, "%s: [%ld] Matched EOF after disconnect\n",
timestamp(), TU_ID(tu));
goto disarm;
} else {
if(exp == -1) {
fprintf(stderr, "%s: [%ld] Expected EOF correctly seen\n",
timestamp(), TU_ID(tu));
} else {
fprintf(stderr, "%s: [%ld] EOF seen when it shouldn't have been\n",
timestamp(), TU_ID(tu));
ret = -1;
}
goto disarm;
}
}
}
trim_eol(msg);
fprintf(stderr, "%s: [%ld] Message from server: %s\n", timestamp(), TU_ID(tu), msg);
new = parse_message(msg, &arg);
if(new > NUM_STATES) {
// Tracing output already produced by parse_message.
ret = -1;
goto disarm;
}
if(new == NUM_STATES) {
// The message is chat. There is no state transition, but we must be
// in the connected state.
if(tu->current_state != TU_CONNECTED) {
fprintf(stderr, "%s: [%ld] Chat received when not in state %s\n",
timestamp(), TU_ID(tu), tu_state_names[tu->current_state]);
ret = -1;
goto disarm;
}
continue;
}
// Check state transition to see if it is as expected.
if(1<<new & tu->expected_states) {
// OK
tu->resync = 0;
} else if(1<<(new+RESYNC) & tu->expected_states) {
// OK, but set resync because messages crossed in transit.
fprintf(stderr, "%s: [%ld] Resync: state %s, expecting %s\n",
timestamp(), TU_ID(tu), tu_state_names[new],
unparse_state_set(tu->expected_states));
tu->resync = 1;
} else {
// New state is not one that is expected -- testing fails.
fprintf(stderr, "%s: [%ld] New state %s is not in expected set %s\n",
timestamp(), TU_ID(tu), tu_state_names[new],
unparse_state_set(tu->expected_states));
ret = -1;
goto disarm;
}
// Update current state to that specified in message
fprintf(stderr, "%s: [%ld] Change state: %s -> %s\n",
timestamp(), TU_ID(tu), tu_state_names[tu->current_state], tu_state_names[new]);
tu->current_state = new;
if(new == TU_ON_HOOK) {
int ext = atoi(arg);
if(tu->extension != ext) {
tu->extension = ext;
}
}
if(new == TU_CONNECTED) {
int ext = atoi(arg);
tu->peer = ext;
} else {
tu->peer = -1;
}
if(tu->resync) {
// If resyncing, update expected states based on last command sent,
// unless we are draining to get EOF.
//fprintf(stderr, "%s: [%ld] Resync\n", timestamp(), TU_ID(tu));
if(tu->expected_states != ~0)
tu->expected_states = next_states[new][tu->last_command];
}
} while(tu->current_state != exp);
disarm:
itv = (struct itimerval) {0};
setitimer(ITIMER_REAL, &itv, NULL);
sigaction(SIGALRM, &oa, NULL);
tu_to_read = NULL;
return ret;
}
/*
* Parse a message from the PBX, determining the new state.
*/
static TU_STATE parse_message(char *msg, char **arg) {
for(int i = 0; i < NUM_STATES; i++) {
if(strstr(msg, tu_state_names[i]) == msg) {
if(arg)
*arg = msg + strlen(tu_state_names[i]);
return i;
}
}
if(strstr(msg, "CHAT") == msg) {
if(arg)
*arg = msg + strlen("CHAT");
return NUM_STATES;
}
fprintf(stderr, "%s: Unrecognized message: %s\n", timestamp(), msg);
return NUM_STATES+1;
}
/*
* Connect to the server at a specified address.
*
* Returns: connection file descriptor in case of success.
* Returns -1 and sets errno in case of error.
*/
static int connect_to_server(struct in_addr *addr, int port) {
struct sockaddr_in sa;
int sfd;
if((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
return(-1);
}
memset(&sa, 0, sizeof(sa));
sa.sin_family = AF_INET;
sa.sin_port = htons(port);
memcpy(&sa.sin_addr.s_addr, addr, sizeof(struct in_addr));
if(connect(sfd, (struct sockaddr *)(&sa), sizeof(sa)) < 0) {
close(sfd);
return(-1);
}
return sfd;
}
/*
* Construct a string representation of an expected state bitmap.
*/
static char *unparse_state_set(int set) {
static char buf[100];
buf[0] = '\0';
strcat(buf, "{ ");
for(int i = 0; i < NUM_STATES; i++) {
if(set & (1<<i) || set & (1<<(i+RESYNC))) {
strcat(buf, tu_state_names[i]);
if(set & (1<<(i+RESYNC)))
strcat(buf, "*");
strcat(buf, " ");
}
}
strcat(buf, "}");
return buf;
}
/*
* Trim EOL characters from the end of a message.
*/
static void trim_eol(char *msg) {
for(char *mp = msg; *mp != '\0'; mp++) {
if(*mp == '\n' || *mp == '\r')
*mp = '\0';
}
}
/*
* Construct a timestamp string for tracing printout.
*/
static char *timestamp() {
static char buf[100];
struct timeval tv;
gettimeofday(&tv, NULL);
sprintf(buf, "%ld.%06ld", tv.tv_sec, tv.tv_usec);
return buf;
}