dadada/netcalc
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Cleanup error handling.

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This commit is contained in:
tim.schubert@tu-bs.de 2016-10-27 17:10:22 +02:00
parent 13a38cd92e
commit 85a5452600
1 changed files with 103 additions and 41 deletions
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144
netcalc.c
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@ -12,17 +12,20 @@
#define BUFLEN 512
int sockfd;
int SOCKFD;
int CLIENT;
void cleanup(int signum)
{
if (close(sockfd) != 0) {
if (close(SOCKFD) != 0) {
perror("close");
}
}
int prepaddr(char *host, char *port, struct addrinfo **ainfo)
{
fprintf(stderr, "debug: %s %s\n", host, port);
struct addrinfo hints; // hints to what we want
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET6; // AF_INET or AF_INET6 to force version
@ -38,34 +41,39 @@ int prepaddr(char *host, char *port, struct addrinfo **ainfo)
return 0;
}
int prepsocket(struct addrinfo *ainfo)
int bindsocket(int sockd, struct addrinfo *ainfo)
{
sockfd = socket(ainfo->ai_family, ainfo->ai_socktype, ainfo->ai_protocol);
if (sockfd == -1) {
perror("socket");
return -1;
}
int yes = 1;
if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) == -1) {
perror("setsockopt");
cleanup(0);
return -1;
}
if (bind(sockfd, ainfo->ai_addr, ainfo->ai_addrlen) != 0) {
if (bind(SOCKFD, ainfo->ai_addr, ainfo->ai_addrlen) != 0) {
perror("bind");
cleanup(0);
return -1;
}
if (listen(sockfd, 5) != 0) {
if (listen(SOCKFD, 5) != 0) {
perror("listen");
cleanup(0);
return -1;
}
return sockfd;
return sockd;
}
int prepsocket(struct addrinfo *ainfo)
{
SOCKFD = socket(ainfo->ai_family, ainfo->ai_socktype, ainfo->ai_protocol);
if (SOCKFD == -1) {
perror("socket");
return -1;
}
int yes = 1;
if (setsockopt(SOCKFD, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) == -1) {
perror("setsockopt");
cleanup(0);
return -1;
}
return SOCKFD;
}
int readnum(char *buf, size_t buflen, unsigned int *res)
@ -105,7 +113,6 @@ int readnum(char *buf, size_t buflen, unsigned int *res)
int calc(unsigned int num1, unsigned int num2, char op, unsigned int *result)
{
// TODO check for over/under flow
switch (op) {
case '+':
if (__builtin_uadd_overflow(num1, num2, result)) {
@ -157,18 +164,27 @@ int parse(char *buf, size_t buflen, unsigned int *first, unsigned int *second, c
return 0;
}
void report_error(char *buf, unsigned long buflen, char *msg)
{
fprintf(stderr, "%s\n", msg);
memset(buf, 0, buflen);
sprintf(buf, "%s\n", msg);
}
int server()
{
while (1) {
struct sockaddr_storage c_addr;
socklen_t sin_size = sizeof c_addr;
int c_fd = accept(sockfd, (struct sockaddr *)&c_addr, &sin_size);
int c_fd = accept(SOCKFD, (struct sockaddr *)&c_addr, &sin_size);
if (c_fd == -1) {
perror("accept");
continue; // we do not care
}
fprintf(stderr, "debug: connected\n");
char buf[BUFLEN];
ssize_t byte_count;
@ -181,49 +197,82 @@ int server()
unsigned int first;
unsigned int second;
char op;
if (parse(buf, sizeof buf, &first, &second, &op) == -1) {
fprintf(stderr, "parser: failed to parse");
continue;
}
memset(buf, 0, sizeof buf);
unsigned int result;
if (calc(first, second, op, &result) == -1) {
char *errormsg = "error: %u %c %u invalid\n";
fprintf(stderr, errormsg, first, op, second);
sprintf(buf, errormsg, first, op, second);
if (parse(buf, sizeof buf, &first, &second, &op) == -1) {
report_error(buf, BUFLEN, "parse: failed to parse");
} else if (calc(first, second, op, &result) == -1) {
report_error(buf, BUFLEN, "calc: failed to calculate");
fprintf(stderr, "debug: %u %c %u\n", first, op, second);
} else {
printf("%u %c %u = %u\n", first, op, second, result);
fprintf(stderr, "debug: %u %c %u = %u\n", first, op, second, result);
// TODO output binary format
memset(buf, 0, sizeof buf);
sprintf(buf, "%u 0x%X \n", result, result);
}
if (send(c_fd, buf, sizeof buf, 0) == -1) {
perror("send");
continue;
}
}
close(c_fd);
}
}
int connectclient(struct addrinfo *ainfo)
{
if (connect(SOCKFD, ainfo->ai_addr, ainfo->ai_addrlen) == -1) {
perror("connect");
return -1;
}
return 0;
}
int client()
{
char sendbuf[512];
char *num1 = NULL;
char *num2 = NULL;
char *op = NULL;
while (scanf("%m[0-9,A-F,x,b]%m[+,-,*,/]%m[0-9,A-F,x,b]", &num1, &op, &num2)) {
//fprintf(stdout, "%s %s %s\n", num1, op, num2);
free(num1);
free(num2);
free(op);
}
}
int main(int argc, char *argv[])
{
char* host = NULL;
char* host = "localhost";
char* port = "5000";
if (argc > 1) {
port = argv[1];
if (strcmp(argv[1], "-c") == 0) {
printf("debug: argv[1] = %s running in client mode\n", argv[1]);
CLIENT = 1; // client mode
if (argc > 3) {
host = argv[2];
port = argv[3];
}
} else {
printf("debug: argv[1] = %s running in server mode\n", argv[1]);
CLIENT = 0;
if (argc > 2) {
host = NULL;
port = argv[1];
}
}
}
struct addrinfo *ainfo;
if (prepaddr(host, port, &ainfo) != 0) {
fprintf(stderr, "server: failed to obtain adress.");
fprintf(stderr, "prepaddr: failed to obtain adress.\n");
return 1;
}
if ((sockfd = prepsocket(ainfo)) == -1) {
if ((SOCKFD = prepsocket(ainfo)) == -1) {
return 1;
}
@ -232,7 +281,20 @@ int main(int argc, char *argv[])
action.sa_handler = cleanup;
sigaction(SIGTERM, &action, NULL);
server();
if (CLIENT) {
connectclient(ainfo);
if (client() == -1) {
fprintf(stderr, "client: error");
}
} else {
if ((SOCKFD = bindsocket(SOCKFD, ainfo)) == -1) {
fprintf(stderr, "bindsocket: failed to bind or listen.");
return 1;
}
if (server() == -1) {
fprintf(stderr, "server: error");
}
}
cleanup(0);
freeaddrinfo(ainfo); // free the linked list