freebsd-dev/lib/libfetch/common.c
Colin Percival fc2841a92f Fix one-byte buffer overflow: NUL gets written to the buffer, but isn't
counted in the width specification in scanf.

This is not a security problem, since this function is only used to
parse a user's configuration file.

Submitted by:	Joerg Sonnenberger
Obtained from:	dragonflybsd
MFC after:	1 week
2008-04-15 23:29:51 +00:00

787 lines
16 KiB
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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <ctype.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;
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 now, timeout, delta;
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);
delta.tv_sec = timeout.tv_sec - now.tv_sec;
delta.tv_usec = timeout.tv_usec - now.tv_usec;
if (delta.tv_usec < 0) {
delta.tv_usec += 1000000;
delta.tv_sec--;
}
if (delta.tv_sec < 0) {
errno = ETIMEDOUT;
fetch_syserr();
return (-1);
}
errno = 0;
r = select(conn->sd + 1, &readfds, NULL, NULL, &delta);
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, delta;
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);
delta.tv_sec = timeout.tv_sec - now.tv_sec;
delta.tv_usec = timeout.tv_usec - now.tv_usec;
if (delta.tv_usec < 0) {
delta.tv_usec += 1000000;
delta.tv_sec--;
}
if (delta.tv_sec < 0) {
errno = ETIMEDOUT;
fetch_syserr();
return (-1);
}
errno = 0;
r = select(conn->sd + 1, NULL, &writefds, NULL, &delta);
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);
memcpy(&tmp->stat, us, 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, " %1023s ", 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);
}
/*
* The no_proxy environment variable specifies a set of domains for
* which the proxy should not be consulted; the contents is a comma-,
* or space-separated list of domain names. A single asterisk will
* override all proxy variables and no transactions will be proxied
* (for compatability with lynx and curl, see the discussion at
* <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
*/
int
fetch_no_proxy_match(const char *host)
{
const char *no_proxy, *p, *q;
size_t h_len, d_len;
if ((no_proxy = getenv("NO_PROXY")) == NULL &&
(no_proxy = getenv("no_proxy")) == NULL)
return (0);
/* asterisk matches any hostname */
if (strcmp(no_proxy, "*") == 0)
return (1);
h_len = strlen(host);
p = no_proxy;
do {
/* position p at the beginning of a domain suffix */
while (*p == ',' || isspace((unsigned char)*p))
p++;
/* position q at the first separator character */
for (q = p; *q; ++q)
if (*q == ',' || isspace((unsigned char)*q))
break;
d_len = q - p;
if (d_len > 0 && h_len > d_len &&
strncasecmp(host + h_len - d_len,
p, d_len) == 0) {
/* domain name matches */
return (1);
}
p = q + 1;
} while (*q);
return (0);
}