/*      $OpenBSD: util.c,v 1.3 2021/07/06 11:50:34 bluhm Exp $  */

/*
 * Copyright (c) 2020 Alexander Bluhm <bluhm@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>

#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "util.h"

void
task_enqueue(struct task *todo, int ch, const char *msg)
{
        switch (ch) {
        case 'E':
                todo->t_type = TEOF;
                todo->t_msg = NULL;
                break;
        case 'N':
                todo->t_type = TDWN;
                todo->t_msg = NULL;
                break;
        case 'r':
                todo->t_type = TRCV;
                todo->t_msg = msg;
                break;
        case 's':
                todo->t_type = TSND;
                todo->t_msg = msg;
                break;
        }
}

void
task_run(int s, struct task *todolist, size_t tlen)
{
        size_t t;

        for (t = 0; t < tlen; t++) {
                switch(todolist[t].t_type) {
                case TEOF:
                        receive_eof(s);
                        break;
                case TDWN:
                        send_shutdown(s);
                        break;
                case TRCV:
                        receive_line(s, todolist[t].t_msg);
                        break;
                case TSND:
                        send_line(s, todolist[t].t_msg);
                        break;
                }
        }
}

void
print_sockname(int s)
{
        struct sockaddr_storage ss;
        socklen_t slen;
        char host[NI_MAXHOST], port[NI_MAXSERV];

        slen = sizeof(ss);
        if (getsockname(s, (struct sockaddr *)&ss, &slen) == -1)
                err(1, "getsockname");
        if (getnameinfo((struct sockaddr *)&ss, ss.ss_len, host, sizeof(host),
            port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV))
                errx(1, "getnameinfo");
        printf("%s\n", port);
        if (fflush(stdout) != 0)
                err(1, "fflush stdout");
        fprintf(stderr, "sock: %s %s\n", host, port);
}

void
print_peername(int s)
{
        struct sockaddr_storage ss;
        socklen_t slen;
        char host[NI_MAXHOST], port[NI_MAXSERV];

        slen = sizeof(ss);
        if (getpeername(s, (struct sockaddr *)&ss, &slen) == -1)
                err(1, "getpeername");
        if (getnameinfo((struct sockaddr *)&ss, ss.ss_len, host, sizeof(host),
            port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV))
                errx(1, "getnameinfo");
        fprintf(stderr, "peer: %s %s\n", host, port);
}

void
receive_eof(int s)
{
        char buf[100];
        size_t len;
        ssize_t n;

        n = recv(s, buf, sizeof(buf) - 1, 0);
        if (n == -1)
                err(1, "recv");
        if (n == 0) {
                fprintf(stderr, "<<< EOF\n");
                return;
        }
        len = n;
        buf[len] = '\0';
        if (buf[len - 1] == '\n')
                buf[--len] = '\0';
        fprintf(stderr, "<<< %s\n", buf);
        errx(1, "expected receive EOF, got '%s'", buf);
}

void
send_shutdown(int s)
{
        if (shutdown(s, SHUT_WR) == -1)
                err(1, "shutdown");
}

void
receive_line(int s, const char *msg)
{
        char buf[100];
        size_t off, len;
        ssize_t n;

        len = 0;
        while (len < sizeof(buf) - 1) {
                off = len;
                n = recv(s, buf + off, sizeof(buf) - 1 - off, 0);
                if (n == -1)
                        err(1, "recv");
                if (n == 0) {
                        fprintf(stderr, "<<< EOF\n");
                        break;
                }
                len += n;
                buf[len] = '\0';
                if (buf[len - 1] == '\n')
                        fprintf(stderr, "<<< %s", buf + off);
                else
                        fprintf(stderr, "<<< %s\n", buf + off);
                if (strchr(buf + off, '\n') != NULL)
                        break;
        }
        if (len == 0)
                errx(1, "empty receive buffer");
        if (buf[len - 1] != '\n')
                errx(1, "new line missing in receive buffer");
        buf[--len] = '\0';
        if (strcmp(msg, buf) != 0)
                errx(1, "expected receive '%s', got '%s'", msg, buf);
}

void
send_line(int s, const char *msg)
{
        char buf[100];
        size_t off, len;
        ssize_t n;

        len = strlcpy(buf, msg, sizeof(buf));
        if (len >= sizeof(buf))
                errx(1, "message too long for send buffer");
        if (buf[len] != '\n') {
                buf[len++] = '\n';
                if (len >= sizeof(buf))
                        errx(1, "new line too long for send buffer");
                buf[len] = 0;
        }

        off = 0;
        while (off < len) {
                fprintf(stderr, ">>> %s", buf + off);
                n = send(s, buf + off, len - off, 0);
                if (n == -1)
                        err(1, "send");
                off += n;
        }
}