/*-
 * Copyright (c) 1998-2004 Dag-Erling Coïdan Smørgrav
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer
 *    in this position and unchanged.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "free2net.h"

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libfetch/common.c,v 1.48.4.2 2006/11/11 00:16:07 des Exp $");

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <netinet/in.h>

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

#include "fetch.h"
#include "common.h"


/*** Local data **************************************************************/

/*
 * Error messages for resolver errors
 */
static struct fetcherr _netdb_errlist[] = {
#ifdef EAI_NODATA
        { EAI_NODATA,   FETCH_RESOLV,   "Host not found" },
#endif
        { EAI_AGAIN,    FETCH_TEMP,     "Transient resolver failure" },
        { EAI_FAIL,     FETCH_RESOLV,   "Non-recoverable resolver failure" },
        { EAI_NONAME,   FETCH_RESOLV,   "No address record" },
        { -1,           FETCH_UNKNOWN,  "Unknown resolver error" }
};

/* End-of-Line */
static const char ENDL[2] = "\r\n";


/*** Error-reporting functions ***********************************************/

/*
 * Map error code to string
 */
static struct fetcherr *
_fetch_finderr(struct fetcherr *p, int e)
{
        while (p->num != -1 && p->num != e)
                p++;
        return (p);
}

/*
 * Set error code
 */
void
_fetch_seterr(struct fetcherr *p, int e)
{
        p = _fetch_finderr(p, e);
        fetchLastErrCode = p->cat;
        snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
}

/*
 * Set error code according to errno
 */
void
_fetch_syserr(void)
{
        switch (errno) {
        case 0:
                fetchLastErrCode = FETCH_OK;
                break;
        case EPERM:
        case EACCES:
        case EROFS:
        case EAUTH:
        case ENEEDAUTH:
                fetchLastErrCode = FETCH_AUTH;
                break;
        case ENOENT:
        case EISDIR: /* XXX */
                fetchLastErrCode = FETCH_UNAVAIL;
                break;
        case ENOMEM:
                fetchLastErrCode = FETCH_MEMORY;
                break;
        case EBUSY:
        case EAGAIN:
                fetchLastErrCode = FETCH_TEMP;
                break;
        case EEXIST:
                fetchLastErrCode = FETCH_EXISTS;
                break;
        case ENOSPC:
                fetchLastErrCode = FETCH_FULL;
                break;
        case EADDRINUSE:
        case EADDRNOTAVAIL:
        case ENETDOWN:
        case ENETUNREACH:
        case ENETRESET:
        case EHOSTUNREACH:
                fetchLastErrCode = FETCH_NETWORK;
                break;
        case ECONNABORTED:
        case ECONNRESET:
                fetchLastErrCode = FETCH_ABORT;
                break;
        case ETIMEDOUT:
                fetchLastErrCode = FETCH_TIMEOUT;
                break;
        case ECONNREFUSED:
        case EHOSTDOWN:
                fetchLastErrCode = FETCH_DOWN;
                break;
default:
                fetchLastErrCode = FETCH_UNKNOWN;
        }
        snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
}


/*
 * Emit status message
 */
void
_fetch_info(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vfprintf(stderr, fmt, ap);
        va_end(ap);
        fputc('\n', stderr);
}


/*** Network-related utility functions ***************************************/

/*
 * Return the default port for a scheme
 */
int
_fetch_default_port(const char *scheme)
{
        struct servent *se;

        if ((se = getservbyname(scheme, "tcp")) != NULL)
                return (ntohs(se->s_port));
        if (strcasecmp(scheme, SCHEME_FTP) == 0)
                return (FTP_DEFAULT_PORT);
        if (strcasecmp(scheme, SCHEME_HTTP) == 0)
                return (HTTP_DEFAULT_PORT);
        return (0);
}

/*
 * Return the default proxy port for a scheme
 */
int
_fetch_default_proxy_port(const char *scheme)
{
        if (strcasecmp(scheme, SCHEME_FTP) == 0)
                return (FTP_DEFAULT_PROXY_PORT);
        if (strcasecmp(scheme, SCHEME_HTTP) == 0)
                return (HTTP_DEFAULT_PROXY_PORT);
        return (0);
}


/*
 * Create a connection for an existing descriptor.
 */
conn_t *
_fetch_reopen(int sd)
{
        conn_t *conn;

        /* allocate and fill connection structure */
        if ((conn = calloc(1, sizeof(*conn))) == NULL)
                return (NULL);
        conn->sd = sd;
        ++conn->ref;
        return (conn);
}


/*
 * Bump a connection's reference count.
 */
conn_t *
_fetch_ref(conn_t *conn)
{

        ++conn->ref;
        return (conn);
}


/*
 * Bind a socket to a specific local address
 */
int
_fetch_bind(int sd, int af, const char *addr)
{
        struct addrinfo hints, *res, *res0;

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = af;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_protocol = 0;
        if (getaddrinfo(addr, NULL, &hints, &res0) != 0)
                return (-1);
        for (res = res0; res; res = res->ai_next)
                if (bind(sd, res->ai_addr, res->ai_addrlen) == 0)
                        return (0);
        return (-1);
}


/*
 * Establish a TCP connection to the specified port on the specified host.
 */
conn_t *
_fetch_connect(const char *host, int port, int af, int verbose)
{
        conn_t *conn;
        char pbuf[10];
        const char *bindaddr;
        struct addrinfo hints, *res, *res0;
        int sd, err;

        DEBUG(fprintf(stderr, "---> %s:%d\n", host, port));

        if (verbose)
                _fetch_info("looking up %s", host);

        /* look up host name and set up socket address structure */
        snprintf(pbuf, sizeof(pbuf), "%d", port);
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = af;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_protocol = 0;
        if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) {
                _netdb_seterr(err);
                return (NULL);
        }
        bindaddr = getenv("FETCH_BIND_ADDRESS");

        if (verbose)
                _fetch_info("connecting to %s:%d", host, port);

        /* try to connect */
        for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) {
                if ((sd = socket(res->ai_family, res->ai_socktype,
                         res->ai_protocol)) == -1)
                        continue;
                if (bindaddr != NULL && *bindaddr != '\0' &&
                    _fetch_bind(sd, res->ai_family, bindaddr) != 0) {
                        _fetch_info("failed to bind to '%s'", bindaddr);
                        close(sd);
                        continue;
                }
                if (connect(sd, res->ai_addr, res->ai_addrlen) == 0)
                        break;
                close(sd);
        }
        freeaddrinfo(res0);
        if (sd == -1) {
                _fetch_syserr();
                return (NULL);
        }

        if ((conn = _fetch_reopen(sd)) == NULL) {
                _fetch_syserr();
                close(sd);
        }
        return (conn);
}


/*
 * Enable SSL on a connection.
 */
int
_fetch_ssl(conn_t *conn, int verbose)
{

#ifdef WITH_SSL
        /* Init the SSL library and context */
        if (!SSL_library_init()){
                fprintf(stderr, "SSL library init failed\n");
                return (-1);
        }

        SSL_load_error_strings();

        conn->ssl_meth = SSLv23_client_method();
        conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
        SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);

        conn->ssl = SSL_new(conn->ssl_ctx);
        if (conn->ssl == NULL){
                fprintf(stderr, "SSL context creation failed\n");
                return (-1);
        }
        SSL_set_fd(conn->ssl, conn->sd);
        if (SSL_connect(conn->ssl) == -1){
                ERR_print_errors_fp(stderr);
                return (-1);
        }

        if (verbose) {
                X509_NAME *name;
                char *str;

                fprintf(stderr, "SSL connection established using %s\n",
                    SSL_get_cipher(conn->ssl));
                conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
                name = X509_get_subject_name(conn->ssl_cert);
                str = X509_NAME_oneline(name, 0, 0);
                printf("Certificate subject: %s\n", str);
                free(str);
                name = X509_get_issuer_name(conn->ssl_cert);
                str = X509_NAME_oneline(name, 0, 0);
                printf("Certificate issuer: %s\n", str);
                free(str);
        }

        return (0);
#else
        /* LINTED */
        (void)conn;
        /* LINTED */
        (void)verbose;
        fprintf(stderr, "SSL support disabled\n");
        return (-1);
#endif
}


/*
 * Read a character from a connection w/ timeout
 */
ssize_t
_fetch_read(conn_t *conn, char *buf, size_t len)
{
        struct timeval now, timeout, wait;
        fd_set readfds;
        ssize_t rlen, total;
        int r;

        if (fetchTimeout) {
                FD_ZERO(&readfds);
                gettimeofday(&timeout, NULL);
                timeout.tv_sec += fetchTimeout;
        }

        total = 0;
        while (len > 0) {
                while (fetchTimeout && !FD_ISSET(conn->sd, &readfds)) {
                        FD_SET(conn->sd, &readfds);
                        gettimeofday(&now, NULL);
                        wait.tv_sec = timeout.tv_sec - now.tv_sec;
                        wait.tv_usec = timeout.tv_usec - now.tv_usec;
                        if (wait.tv_usec < 0) {
                                wait.tv_usec += 1000000;
                                wait.tv_sec--;
                        }
                        if (wait.tv_sec < 0) {
                                errno = ETIMEDOUT;
                                _fetch_syserr();
                                return (-1);
                        }
                        errno = 0;
                        r = select(conn->sd + 1, &readfds, NULL, NULL, &wait);
                        if (r == -1) {
                                if (errno == EINTR && fetchRestartCalls)
                                        continue;
                                _fetch_syserr();
                                return (-1);
                        }
                }
#ifdef WITH_SSL
                if (conn->ssl != NULL)
                        rlen = SSL_read(conn->ssl, buf, len);
                else
#endif
                        rlen = read(conn->sd, buf, len);
                if (rlen == 0)
                        break;
                if (rlen < 0) {
                        if (errno == EINTR && fetchRestartCalls)
                                continue;
                        return (-1);
                }
                len -= rlen;
                buf += rlen;
                total += rlen;
        }
        return (total);
}


/*
 * Read a line of text from a connection w/ timeout
 */
#define MIN_BUF_SIZE 1024

int
_fetch_getln(conn_t *conn)
{
        char *tmp;
        size_t tmpsize;
        ssize_t len;
        char c;

        if (conn->buf == NULL) {
                if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
                        errno = ENOMEM;
                        return (-1);
                }
                conn->bufsize = MIN_BUF_SIZE;
        }

        conn->buf[0] = '\0';
        conn->buflen = 0;

        do {
                len = _fetch_read(conn, &c, 1);
                if (len == -1)
                        return (-1);
                if (len == 0)
                        break;
                conn->buf[conn->buflen++] = c;
                if (conn->buflen == conn->bufsize) {
                        tmp = conn->buf;
                        tmpsize = conn->bufsize * 2 + 1;
                        if ((tmp = realloc(tmp, tmpsize)) == NULL) {
                                errno = ENOMEM;
                                return (-1);
                        }
                        conn->buf = tmp;
                        conn->bufsize = tmpsize;
                }
        } while (c != '\n');

        conn->buf[conn->buflen] = '\0';
        DEBUG(fprintf(stderr, "<<< %s", conn->buf));
        return (0);
}


/*
 * Write to a connection w/ timeout
 */
ssize_t
_fetch_write(conn_t *conn, const char *buf, size_t len)
{
        struct iovec iov;

        iov.iov_base = __DECONST(char *, buf);
        iov.iov_len = len;
        return _fetch_writev(conn, &iov, 1);
}

/*
 * Write a vector to a connection w/ timeout
 * Note: can modify the iovec.
 */
ssize_t
_fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
{
        struct timeval now, timeout, wait;
        fd_set writefds;
        ssize_t wlen, total;
        int r;

        if (fetchTimeout) {
                FD_ZERO(&writefds);
                gettimeofday(&timeout, NULL);
                timeout.tv_sec += fetchTimeout;
        }

        total = 0;
        while (iovcnt > 0) {
                while (fetchTimeout && !FD_ISSET(conn->sd, &writefds)) {
                        FD_SET(conn->sd, &writefds);
                        gettimeofday(&now, NULL);
                        wait.tv_sec = timeout.tv_sec - now.tv_sec;
                        wait.tv_usec = timeout.tv_usec - now.tv_usec;
                        if (wait.tv_usec < 0) {
                                wait.tv_usec += 1000000;
                                wait.tv_sec--;
                        }
                        if (wait.tv_sec < 0) {
                                errno = ETIMEDOUT;
                                _fetch_syserr();
                                return (-1);
                        }
                        errno = 0;
                        r = select(conn->sd + 1, NULL, &writefds, NULL, &wait);
                        if (r == -1) {
                                if (errno == EINTR && fetchRestartCalls)
                                        continue;
                                return (-1);
                        }
                }
                errno = 0;
#ifdef WITH_SSL
                if (conn->ssl != NULL)
                        wlen = SSL_write(conn->ssl,
                            iov->iov_base, iov->iov_len);
                else
#endif
                        wlen = writev(conn->sd, iov, iovcnt);
                if (wlen == 0) {
                        /* we consider a short write a failure */
                        errno = EPIPE;
                        _fetch_syserr();
                        return (-1);
                }
                if (wlen < 0) {
                        if (errno == EINTR && fetchRestartCalls)
                                continue;
                        return (-1);
                }
                total += wlen;
                while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
                        wlen -= iov->iov_len;
                        iov++;
                        iovcnt--;
                }
                if (iovcnt > 0) {
                        iov->iov_len -= wlen;
                        iov->iov_base = (__DECONST(char *, iov->iov_base)) + wlen;
                }
        }
        return (total);
}


/*
 * Write a line of text to a connection w/ timeout
 */
int
_fetch_putln(conn_t *conn, const char *str, size_t len)
{
        struct iovec iov[2];
        int ret;

        DEBUG(fprintf(stderr, ">>> %s\n", str));
        iov[0].iov_base = __DECONST(char *, str);
        iov[0].iov_len = len;
        iov[1].iov_base = __DECONST(char *, ENDL);
        iov[1].iov_len = sizeof(ENDL);
        if (len == 0)
                ret = _fetch_writev(conn, &iov[1], 1);
        else
                ret = _fetch_writev(conn, iov, 2);
        if (ret == -1)
                return (-1);
        return (0);
}


/*
 * Close connection
 */
int
_fetch_close(conn_t *conn)
{
        int ret;

        if (--conn->ref > 0)
                return (0);
        ret = close(conn->sd);
        free(conn->buf);
        free(conn);
        return (ret);
}


/*** Directory-related utility functions *************************************/

int
_fetch_add_entry(struct url_ent **p, int *size, int *len,
    const char *name, struct url_stat *us)
{
        struct url_ent *tmp;

        if (*p == NULL) {
                *size = 0;
                *len = 0;
        }

        if (*len >= *size - 1) {
                tmp = realloc(*p, (*size * 2 + 1) * sizeof(**p));
                if (tmp == NULL) {
                        errno = ENOMEM;
                        _fetch_syserr();
                        return (-1);
                }
                *size = (*size * 2 + 1);
                *p = tmp;
        }

        tmp = *p + *len;
        snprintf(tmp->name, PATH_MAX, "%s", name);
        bcopy(us, &tmp->stat, sizeof(*us));

        (*len)++;
        (++tmp)->name[0] = 0;

        return (0);
}


/*** Authentication-related utility functions ********************************/

static const char *
_fetch_read_word(FILE *f)
{
        static char word[1024];

        if (fscanf(f, " %1024s ", word) != 1)
                return (NULL);
        return (word);
}

/*
 * Get authentication data for a URL from .netrc
 */
int
_fetch_netrc_auth(struct url *url)
{
        char fn[PATH_MAX];
        const char *word;
        char *p;
        FILE *f;

        if ((p = getenv("NETRC")) != NULL) {
                if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
                        _fetch_info("$NETRC specifies a file name "
                            "longer than PATH_MAX");
                        return (-1);
                }
        } else {
                if ((p = getenv("HOME")) != NULL) {
                        struct passwd *pwd;

                        if ((pwd = getpwuid(getuid())) == NULL ||
                            (p = pwd->pw_dir) == NULL)
                                return (-1);
                }
                if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
                        return (-1);
        }

        if ((f = fopen(fn, "r")) == NULL)
                return (-1);
        while ((word = _fetch_read_word(f)) != NULL) {
                if (strcmp(word, "default") == 0) {
                        DEBUG(_fetch_info("Using default .netrc settings"));
                        break;
                }
                if (strcmp(word, "machine") == 0 &&
                    (word = _fetch_read_word(f)) != NULL &&
                    strcasecmp(word, url->host) == 0) {
                        DEBUG(_fetch_info("Using .netrc settings for %s", word));
                        break;
                }
        }
        if (word == NULL)
                goto ferr;
        while ((word = _fetch_read_word(f)) != NULL) {
                if (strcmp(word, "login") == 0) {
                        if ((word = _fetch_read_word(f)) == NULL)
                                goto ferr;
                        if (snprintf(url->user, sizeof(url->user),
                                "%s", word) > (int)sizeof(url->user)) {
                                _fetch_info("login name in .netrc is too long");
                                url->user[0] = '\0';
                        }
                } else if (strcmp(word, "password") == 0) {
                        if ((word = _fetch_read_word(f)) == NULL)
                                goto ferr;
                        if (snprintf(url->pwd, sizeof(url->pwd),
                                "%s", word) > (int)sizeof(url->pwd)) {
                                _fetch_info("password in .netrc is too long");
                                url->pwd[0] = '\0';
                        }
                } else if (strcmp(word, "account") == 0) {
                        if ((word = _fetch_read_word(f)) == NULL)
                                goto ferr;
                        /* XXX not supported! */
                } else {
                        break;
                }
        }
        fclose(f);
        return (0);
 ferr:
        fclose(f);
        return (-1);
}