path: root/lib/libfetch/common.c

/*-
* 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 <sys/cdefs.h>

#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:
    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;
int err;

memset(&hints, 0, sizeof(hints));
hints.ai_family = af;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
if ((err = 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
(void)conn;
(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 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);
        }
        */
        wait.tv_sec = fetchTimeout / 1000;
        wait.tv_usec = (fetchTimeout % 1000) * 1000;
        errno = 0;
        r = select(conn->sd + 1, &readfds, NULL, NULL, &wait);
        if (r == -1) {
            if (errno == EINTR && fetchRestartCalls)
                continue;
            _fetch_syserr();
            return (-1);
        } else if (r == 0) {
            errno = ETIMEDOUT;
            _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 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);
			}
            */
            wait.tv_sec = fetchTimeout / 1000;
            wait.tv_usec = (fetchTimeout % 1000) * 1000;
			errno = 0;
			r = select(conn->sd + 1, NULL, &writefds, NULL, &wait);
			if (r == -1) {
				if (errno == EINTR && fetchRestartCalls)
					continue;
				return (-1);
			} else if (r == 0) {
                errno = ETIMEDOUT;
				_fetch_syserr();
				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);
}