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#include <nserve.h>
int slurpsock(char *buf, size_t buf_sz, int sock)
{
ssize_t bytes;
bytes = recv(sock, buf, buf_sz, 0);
check(bytes >= 0, "Failed to read from socket: %d", sock);
return bytes;
error:
return -1;
}
int barfsock(char *buf, size_t buf_sz, int sock)
{
ssize_t bytes = 0;
bytes = send(sock, buf, buf_sz, 0);
check(bytes >= 0, "barfsock: send failed");
return bytes;
error:
return -1;
}
int sanitize(char *cmd)
{
check(cmd != NULL, "cmd is NULL");
size_t len = strlen(cmd);
check(len > 0, "cmd empty");
// strip newline character at the end.
cmd[len - 1] = '\0';
return 0;
error:
return -1;
}
char *check_cmd(char *cmd)
{
char *err = NULL;
check(cmd != NULL, "cmd is NULL");
int rc = sanitize(cmd);
check(rc != -1, "sanitize failed");
size_t len = strlen(cmd);
if (len >= CMD_MIN_SIZE && len <= CMD_MAX_SIZE) {
return NULL;
}
if (len == 0) {
err = "closing connection\n";
} else {
err = "command size invalid\n";
}
return err;
error:
err = "internal error\n";
return err;
}
void nserve(int sock)
{
size_t cmd_sz = 200;
char *cmd = calloc(sizeof(char), cmd_sz);
check_mem(cmd);
int rc = 0;
char *err = NULL;
do {
// clear cmd.
memset(cmd, '\0', cmd_sz);
// Read command from socket.
ssize_t bytes = slurpsock(cmd, cmd_sz, sock);
check(bytes >= 0, "nserve: slurpsock failed");
err = check_cmd(cmd);
if (err != NULL) {
// cmd invalid; quit.
rc = barfsock(err, strlen(err), sock);
check(rc != -1, "barfsock failed");
break;
}
// Write response to socket.
rc = barfsock(cmd, bytes, sock);
check(rc != -1, "nserve: echo failed");
} while(1);
// Close socket.
rc = close(sock);
check(rc == 0, "nserve: close failed");
// Cleanup.
free(cmd);
exit(0);
error:
rc = close(sock);
check(rc == 0, "nserve: close failed");
// Cleanup if needed.
if (cmd)
free(cmd);
exit(1);
}
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