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freebsd-src/usr.bin/fetch/http.c
Garrett Wollman efd4ad4cd2 Fix the error message for when mirroring and restarting are rejected 
due to the output not being a regular file.  Also split the error message
in any error case here to be on two lines to lessen the likelihood of it
being too long to fit on just one.
1997-07-26 20:00:05 +00:00

1714 lines
43 KiB
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/*-
* Copyright 1997 Massachusetts Institute of Technology
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
* granted, provided that both the above copyright notice and this
* permission notice appear in all copies, that both the above
* copyright notice and this permission notice appear in all
* supporting documentation, and that the name of M.I.T. not be used
* in advertising or publicity pertaining to distribution of the
* software without specific, written prior permission. M.I.T. makes
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied
* warranty.
*
* THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
* ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
* SHALL M.I.T. 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.
*
* $Id: http.c,v 1.8 1997/07/26 19:25:56 wollman Exp $
*/
#include <sys/types.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <md5.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <time.h>
#include <unistd.h>
#include <sys/param.h> /* for MAXHOSTNAMELEN */
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "fetch.h"
struct http_state {
char *http_hostname;
char *http_remote_request;
char *http_decoded_file;
char *http_host_header;
char *http_authentication;
char *http_proxy_authentication;
unsigned http_port;
int http_redirected;
};
struct http_auth {
TAILQ_ENTRY(http_auth) ha_link;
char *ha_scheme;
char *ha_realm;
char *ha_params;
const struct http_auth_method *ha_ham;
};
TAILQ_HEAD(http_auth_head, http_auth);
static int http_parse(struct fetch_state *fs, const char *uri);
static int http_proxy_parse(struct fetch_state *fs, const char *uri);
static int http_close(struct fetch_state *fs);
static int http_retrieve(struct fetch_state *fs);
static int basic_doauth(struct fetch_state *fs, struct http_auth *ha, int prx);
struct uri_scheme http_scheme =
{ "http", http_parse, http_proxy_parse, "HTTP_PROXY", "http" };
struct http_auth_head http_auth, http_proxy_auth;
struct http_auth_method {
const char *ham_scheme;
int (*ham_doauth)(struct fetch_state *, struct http_auth *, int);
} http_auth_methods[] = {
{ "basic", basic_doauth },
{ 0, 0 }
};
/* We are only concerned with headers we might receive. */
enum http_header {
ht_accept_ranges, ht_age, ht_allow, ht_cache_control, ht_connection,
ht_content_base, ht_content_encoding, ht_content_language,
ht_content_length, ht_content_location, ht_content_md5,
ht_content_range, ht_content_type, ht_date, ht_etag, ht_expires,
ht_last_modified, ht_location, ht_pragma, ht_proxy_authenticate,
ht_public, ht_retry_after, ht_server, ht_transfer_encoding,
ht_upgrade, ht_vary, ht_via, ht_www_authenticate, ht_warning,
/* unusual cases */
ht_syntax_error, ht_unknown, ht_end_of_header
};
static char *format_http_date(time_t when);
static char *format_http_user_agent(void);
static enum http_header http_parse_header(char *line, char **valuep);
static int check_md5(FILE *fp, char *base64ofmd5);
static int http_first_line(const char *line);
static int http_suck(struct fetch_state *fs, FILE *remote, FILE *local,
off_t total_length, int timo);
static int http_suck_chunked(struct fetch_state *fs, FILE *remote, FILE *local,
off_t total_length, int timo);
static int parse_http_content_range(char *orig, off_t *first, off_t *total);
static int process_http_auth(struct fetch_state *fs, char *hdr, int autherr);
static struct http_auth *find_http_auth(struct http_auth_head *list,
const char *scheme, const char *realm);
static time_t parse_http_date(char *datestring);
static void setup_http_auth(void);
static int
http_parse(struct fetch_state *fs, const char *uri)
{
const char *p, *colon, *slash, *ques, *q;
char *hostname, *hosthdr, *trimmed_name;
unsigned port;
struct http_state *https;
p = uri + 5;
port = 0;
if (p[0] != '/' || p[1] != '/') {
warnx("`%s': malformed `http' URL", uri);
return EX_USAGE;
}
p += 2;
colon = strchr(p, ':');
slash = strchr(p, '/');
if (colon && slash && colon < slash)
q = colon;
else
q = slash;
if (q == 0) {
warnx("`%s': malformed `http' URL", uri);
return EX_USAGE;
}
hostname = alloca(q - p + 1);
hostname[0] = '\0';
strncat(hostname, p, q - p);
p = slash;
if (colon && colon + 1 != slash) {
unsigned long ul;
char *ep;
errno = 0;
ul = strtoul(colon + 1, &ep, 10);
if (ep != slash || ep == colon + 1 || errno != 0
|| ul < 1 || ul > 65534) {
warn("`%s': invalid port in URL", uri);
return EX_USAGE;
}
port = ul;
} else {
port = 80;
}
p = slash;
https = safe_malloc(sizeof *https);
/*
* Now, we have a copy of the hostname in hostname, the specified port
* (or the default value) in port, and p points to the filename part
* of the URI.
*/
https->http_hostname = safe_strdup(hostname);
https->http_port = port;
hosthdr = alloca(sizeof("Host: :\r\n") + 5 + strlen(hostname));
sprintf(hosthdr, "Host: %s:%d\r\n", hostname, port);
https->http_host_header = safe_strdup(hosthdr);
/*
* NB: HTTP/1.1 servers MUST also accept a full URI.
* However, HTTP/1.0 servers will ONLY accept a trimmed URI.
*/
https->http_remote_request = safe_strdup(p);
p++;
ques = strpbrk(p, "?#");
if (ques) {
trimmed_name = safe_strndup(p, ques - p);
} else {
trimmed_name = safe_strdup(p);
}
https->http_decoded_file = percent_decode(trimmed_name);
free(trimmed_name);
p = https->http_decoded_file;
/* now p is the decoded version, so we can extract the basename */
if (fs->fs_outputfile == 0) {
slash = strrchr(p, '/');
if (slash)
fs->fs_outputfile = slash + 1;
else
fs->fs_outputfile = p;
}
https->http_redirected = 0;
https->http_authentication = https->http_proxy_authentication = 0;
fs->fs_proto = https;
fs->fs_close = http_close;
fs->fs_retrieve = http_retrieve;
return 0;
}
/*
* An HTTP proxy works by accepting a complete URI in a GET request,
* retrieving that object, and then forwarding it back to us. Because
* it can conceivably handle any URI, we have to do a bit more work
* in the parsing of it.
*/
static int
http_proxy_parse(struct fetch_state *fs, const char *uri)
{
struct http_state *https;
const char *env, *slash, *ques;
char *file;
int rv;
https = safe_malloc(sizeof *https);
https->http_remote_request = safe_strdup(uri);
env = getenv("HTTP_PROXY");
rv = parse_host_port(env, &https->http_hostname, &https->http_port);
if (rv) {
out:
free(https->http_remote_request);
free(https);
return rv;
}
if (strncmp(uri, "http://", 7) == 0) {
char *hosthdr;
slash = strchr(uri + 7, '/');
if (slash == 0) {
warnx("`%s': malformed `http' URL", uri);
rv = EX_USAGE;
free(https->http_hostname);
goto out;
}
ques = strpbrk(slash, "?#");
if (ques == 0)
file = safe_strdup(slash);
else
file = safe_strndup(slash, ques - slash);
hosthdr = alloca(sizeof("Host: \r\n") + slash - uri - 7);
strcpy(hosthdr, "Host: ");
strncat(hosthdr, uri + 7, slash - uri - 7);
strcat(hosthdr, "\r\n");
https->http_host_header = safe_strdup(hosthdr);
} else {
slash = uri;
while (*slash && *slash != ':')
slash++;
if (*slash)
slash++;
if (slash[0] == '/' && slash[1] == '/') {
slash += 2;
while (*slash && *slash != '/')
slash++;
}
file = safe_strdup(slash);
https->http_host_header = safe_strdup("");
}
https->http_decoded_file = percent_decode(file);
https->http_redirected = 0;
https->http_authentication = https->http_proxy_authentication = 0;
free(file);
if (fs->fs_outputfile == 0) {
slash = strrchr(https->http_decoded_file, '/');
/* NB: we are not guaranteed to find one... */
fs->fs_outputfile = slash ? slash + 1
: https->http_decoded_file;
}
fs->fs_proto = https;
fs->fs_close = http_close;
fs->fs_retrieve = http_retrieve;
return 0;
}
static int
http_close(struct fetch_state *fs)
{
struct http_state *https = fs->fs_proto;
free(https->http_hostname);
free(https->http_remote_request);
free(https->http_decoded_file);
free(https->http_host_header);
if (https->http_authentication)
free(https->http_authentication);
if (https->http_proxy_authentication)
free(https->http_proxy_authentication);
free(https);
fs->fs_outputfile = 0;
return 0;
}
static int
nullclose(struct fetch_state *fs)
{
return 0;
}
/*
* Process a redirection. This has a small memory leak.
*/
static int
http_redirect(struct fetch_state *fs, char *new, int permanent)
{
struct http_state *https = fs->fs_proto;
int num_redirects = https->http_redirected + 1;
char *out = safe_strdup(fs->fs_outputfile);
int rv;
if (num_redirects > 5) {
warnx("%s: HTTP redirection limit exceeded");
return EX_PROTOCOL;
}
free(https->http_hostname);
free(https->http_remote_request);
free(https->http_decoded_file);
free(https);
warnx("%s: resource has moved %s to `%s'", out,
permanent ? "permanently" : "temporarily", new);
rv = http_parse(fs, new);
if (rv != 0) {
fs->fs_close = nullclose; /* XXX rethink interface? */
return rv;
}
https = fs->fs_proto;
https->http_redirected = num_redirects;
/*
* This ensures that the output file name doesn't suddenly change
* under the user's feet. Unfortunately, this results in a small
* memory leak. I wish C had garbage collection...
*/
fs->fs_outputfile = out;
rv = http_retrieve(fs);
return rv;
}
/*
* Read HTML-formatted data from remote and display it on stderr.
* This is extremely incomplete, as all it does is delete anything
* between angle brackets. However, this is usually good enough for
* error messages.
*/
static void
html_display(FILE *remote)
{
char *line;
int linelen;
int inbracket = 0;
while ((line = fgetln(remote, &linelen)) != 0) {
char *end = line + linelen;
char *p;
int content = 0;
for (p = line; p < end; p++) {
if (*p == '<' && !inbracket) {
fwrite(line, 1, (p - line),
stderr);
inbracket = 1;
}
if (!inbracket && !content &&
*p != '\n' && *p != '\r')
content = 1;
if (*p == '>' && inbracket) {
line = p + 1;
inbracket = 0;
}
}
if (content && line < end)
fwrite(line, 1, (end - line), stderr);
}
}
/*
* Get a file using HTTP. We will try to implement HTTP/1.1 eventually.
* This subroutine makes heavy use of the 4.4-Lite standard I/O library,
* in particular the `fgetln' which allows us to slurp an entire `line'
* (an arbitrary string of non-NUL characters ending in a newline) directly
* out of the stdio buffer. This makes interpreting the HTTP headers much
* easier, since they are all guaranteed to end in `\r\n' and we can just
* ignore the `\r'.
*/
static int
http_retrieve(struct fetch_state *fs)
{
struct http_state *https;
FILE *remote, *local;
int s;
struct sockaddr_in sin;
struct msghdr msg;
#define NIOV 16 /* max is currently 14 */
struct iovec iov[NIOV];
int n, status;
const char *env;
int timo;
char *line, *new_location;
char *errstr = 0;
size_t linelen, writeresult;
off_t total_length, restart_from;
time_t last_modified, when_to_retry;
char *base64ofmd5;
int to_stdout, restarting, redirection, retrying, autherror, chunked;
char rangebuf[sizeof("Range: bytes=18446744073709551616-\r\n")];
setup_http_auth();
https = fs->fs_proto;
to_stdout = (strcmp(fs->fs_outputfile, "-") == 0);
restarting = fs->fs_restart;
redirection = 0;
retrying = 0;
/*
* Figure out the timeout. Prefer the -T command-line value,
* otherwise the HTTP_TIMEOUT envar, or else don't time out at all.
*/
if (fs->fs_timeout) {
timo = fs->fs_timeout;
} else if ((env = getenv("HTTP_TIMEOUT")) != 0) {
char *ep;
unsigned long ul;
errno = 0;
ul = strtoul(env, &ep, 0);
if (*ep != '\0' || *env == '\0' || errno != 0
|| ul > INT_MAX) {
warnx("`%s': invalid timeout", env);
return EX_USAGE;
}
timo = ul;
} else {
timo = 0;
}
memset(&sin, 0, sizeof sin);
sin.sin_family = AF_INET;
sin.sin_len = sizeof sin;
sin.sin_port = htons(https->http_port);
fs->fs_status = "looking up hostname";
if (inet_aton(https->http_hostname, &sin.sin_addr) == 0) {
struct hostent *hp;
/* XXX - do timeouts for name resolution? */
hp = gethostbyname2(https->http_hostname, AF_INET);
if (hp == 0) {
warnx("`%s': cannot resolve: %s", https->http_hostname,
hstrerror(h_errno));
return EX_NOHOST;
}
memcpy(&sin.sin_addr, hp->h_addr_list[0], sizeof sin.sin_addr);
}
fs->fs_status = "creating request message";
msg.msg_name = (caddr_t)&sin;
msg.msg_namelen = sizeof sin;
msg.msg_iov = iov;
n = 0;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = fs->fs_linux_bug ? 0 : MSG_EOF;
#define addstr(Iov, N, Str) \
do { \
Iov[N].iov_base = (void *)Str; \
Iov[N].iov_len = strlen(Iov[n].iov_base); \
N++; \
} while(0)
retry:
addstr(iov, n, "GET ");
addstr(iov, n, https->http_remote_request);
addstr(iov, n, " HTTP/1.1\r\n");
/*
* The choice of HTTP/1.1 may be a bit controversial. The
* specification says that implementations which are not at
* least conditionally compliant MUST NOT call themselves
* HTTP/1.1. We choose not to comply with that requirement.
* (Eventually we will support the full HTTP/1.1, at which
* time this comment will not apply. But it's amusing how
* specifications attempt to define behavior for implementations
* which aren't obeying the spec in the first place...)
*/
addstr(iov, n, format_http_user_agent());
/* do content negotiation here */
addstr(iov, n, "Accept: */*\r\n");
addstr(iov, n, https->http_host_header);
addstr(iov, n, "Connection: close\r\n");
if (https->http_proxy_authentication)
addstr(iov, n, https->http_proxy_authentication);
if (https->http_authentication)
addstr(iov, n, https->http_authentication);
if (fs->fs_mirror) {
struct stat stab;
errno = 0;
if (((!to_stdout && stat(fs->fs_outputfile, &stab) == 0)
|| (to_stdout && fstat(STDOUT_FILENO, &stab) == 0))
&& S_ISREG(stab.st_mode)) {
addstr(iov, n, "If-Modified-Since: ");
addstr(iov, n, format_http_date(stab.st_mtime));
addstr(iov, n, "\r\n");
} else if (errno != 0 || !S_ISREG(stab.st_mode)) {
if (errno != 0)
warn("%s", fs->fs_outputfile);
else
warnx("%s: not a regular file",
fs->fs_outputfile);
warnx("cannot mirror; will retrieve anew");
}
}
if (restarting) {
struct stat stab;
errno = 0;
if (((!to_stdout && stat(fs->fs_outputfile, &stab) == 0)
|| (to_stdout && fstat(STDOUT_FILENO, &stab) == 0))
&& S_ISREG(stab.st_mode)) {
addstr(iov, n, "If-Range: ");
addstr(iov, n, format_http_date(stab.st_mtime));
addstr(iov, n, "\r\n");
sprintf(rangebuf, "Range: bytes=%qd-\r\n",
(quad_t)stab.st_size);
addstr(iov, n, rangebuf);
} else if (errno != 0 || !S_ISREG(stab.st_mode)) {
if (errno != 0)
warn("%s", fs->fs_outputfile);
else
warnx("%s: not a regular file",
fs->fs_outputfile);
restarting = 0;
warnx("cannot restart; will retrieve anew");
}
}
addstr(iov, n, "\r\n");
msg.msg_iovlen = n;
if (n >= NIOV)
err(EX_SOFTWARE, "request vector length exceeded: %d", n);
s = socket(PF_INET, SOCK_STREAM, 0);
if (s < 0) {
warn("socket");
return EX_OSERR;
}
remote = fdopen(s, "r");
if (remote == 0) {
warn("fdopen");
close(s);
return EX_OSERR;
}
fs->fs_status = "sending request message";
setup_sigalrm();
alarm(timo);
if (sendmsg(s, &msg, fs->fs_linux_bug ? 0 : MSG_EOF) < 0) {
warn("sendmsg: %s", https->http_hostname);
fclose(remote);
return EX_OSERR;
}
got100reply:
fs->fs_status = "reading reply status";
alarm(timo);
line = fgetln(remote, &linelen);
alarm(0);
if (line == 0) {
if (ferror(remote)) {
warn("reading reply from %s", https->http_hostname);
fclose(remote);
unsetup_sigalrm();
return EX_OSERR;
} else {
warnx("empty reply from %s", https->http_hostname);
fclose(remote);
unsetup_sigalrm();
return EX_PROTOCOL;
}
}
/*
* If the other end is HTTP 0.9, then we just suck their
* response over; can't do anything fancy. We assume that
* the file is a text file, so it is safe to use fgetln()
* to suck the entire file. (It had better be, since
* we used it to grab the first line.)
*/
if (linelen < 5 || strncasecmp(line, "http", 4) != 0) {
if (to_stdout)
local = fopen("/dev/stdout", "w");
else
local = fopen(fs->fs_outputfile, "w");
if (local == 0) {
warn("%s: fopen", fs->fs_outputfile);
fclose(remote);
unsetup_sigalrm();
return EX_OSERR;
}
fs->fs_status = "retrieving from HTTP/0.9 server";
display(fs, -1, 0);
do {
writeresult = fwrite(line, 1, linelen, local);
display(fs, -1, writeresult);
if (writeresult != linelen)
break;
alarm(timo);
line = fgetln(remote, &linelen);
alarm(0);
} while(line != 0);
unsetup_sigalrm();
if (ferror(local)) {
warn("%s", fs->fs_outputfile);
fclose(local);
fclose(remote);
rm(fs);
return EX_OSERR;
} else if(ferror(remote)) {
warn("%s", https->http_hostname);
fclose(local);
fclose(remote);
rm(fs);
return EX_OSERR;
}
fclose(local);
fclose(remote);
display(fs, -1, -1);
return 0;
}
/*
* OK. The other end is doing HTTP 1.0 at the very least.
* This means that some of the fancy stuff is at least possible.
*/
autherror = 0;
line[linelen - 1] = '\0'; /* turn line into a string */
status = http_first_line(line);
/* In the future, we might handle redirection and other responses. */
switch(status) {
case 100: /* Continue */
goto got100reply;
case 200: /* Here come results */
case 203: /* Non-Authoritative Information */
restarting = 0;
break;
case 206: /* Here come partial results */
/* can only happen when restarting */
break;
case 301: /* Resource has moved permanently */
if (!fs->fs_auto_retry)
errstr = safe_strdup(line);
else
redirection = 301;
break;
case 302: /* Resource has moved temporarily */
/*
* We don't test fs->fs_auto_retry here so that this
* sort of redirection is transparent to the user.
*/
redirection = 302;
break;
case 304: /* Object is unmodified */
if (fs->fs_mirror) {
fclose(remote);
unsetup_sigalrm();
return 0;
}
errstr = safe_strdup(line);
break;
case 401: /* Unauthorized */
if (https->http_authentication)
errstr = safe_strdup(line);
else
autherror = 401;
break;
case 407: /* Proxy Authentication Required */
if (https->http_proxy_authentication)
errstr = safe_strdup(line);
else
autherror = 407;
break;
case 503: /* Service Unavailable */
if (!fs->fs_auto_retry)
errstr = safe_strdup(line);
else
retrying = 503;
break;
default:
errstr = safe_strdup(line);
break;
}
total_length = -1; /* -1 means ``don't know'' */
last_modified = when_to_retry = -1;
base64ofmd5 = 0;
new_location = 0;
restart_from = 0;
chunked = 0;
fs->fs_status = "parsing reply headers";
while((line = fgetln(remote, &linelen)) != 0) {
char *value, *ep;
enum http_header header;
unsigned long ul;
line[linelen - 1] = '\0';
header = http_parse_header(line, &value);
if (header == ht_end_of_header)
break;
switch(header) {
case ht_content_length:
errno = 0;
ul = strtoul(value, &ep, 10);
if (errno != 0 || *ep)
warnx("invalid Content-Length: `%s'", value);
if (!restarting)
total_length = ul;
break;
case ht_last_modified:
last_modified = parse_http_date(value);
if (last_modified == -1 && fs->fs_verbose > 0)
warnx("invalid Last-Modified: `%s'", value);
break;
case ht_content_md5:
base64ofmd5 = safe_strdup(value);
break;
case ht_content_range:
if (!restarting) /* XXX protocol error */
break;
/* NB: we might have to restart from farther back
than we asked. */
status = parse_http_content_range(value, &restart_from,
&total_length);
/* If we couldn't understand the reply, get the whole
thing. */
if (status) {
restarting = 0;
doretry:
fclose(remote);
if (base64ofmd5)
free(base64ofmd5);
if (new_location)
free(new_location);
restart_from = 0;
n = 0;
goto retry;
}
break;
case ht_location:
if (redirection) {
char *s = value;
while (*s && !isspace(*s))
s++;
new_location = safe_strndup(value, s - value);
}
break;
case ht_transfer_encoding:
if (strncasecmp(value, "chunked", 7) == 0) {
chunked = 1;
break;
}
warnx("%s: %s specified Transfer-Encoding `%s'",
fs->fs_outputfile, https->http_hostname,
value);
warnx("%s: output file may be uninterpretable",
fs->fs_outputfile);
break;
case ht_retry_after:
if (!retrying)
break;
errno = 0;
ul = strtoul(value, &ep, 10);
if (errno != 0 || (*ep && !isspace(*ep))) {
time_t when;
when = parse_http_date(value);
if (when == -1)
break;
when_to_retry = when;
} else {
when_to_retry = time(0) + ul;
}
break;
case ht_www_authenticate:
if (autherror != 401)
break;
status = process_http_auth(fs, value, autherror);
if (status != 0)
goto cantauth;
break;
case ht_proxy_authenticate:
if (autherror != 407)
break;
status = process_http_auth(fs, value, autherror);
if (status != 0)
goto cantauth;
break;
default:
break;
}
}
if (autherror == 401 && https->http_authentication)
goto doretry;
if (autherror == 407 && https->http_proxy_authentication)
goto doretry;
if (autherror) {
goto spewerror;
}
if (retrying) {
int howlong;
if (when_to_retry == -1) {
errstr = safe_strdup("HTTP/1.1 503 Service Unavailable");
goto spewerror;
}
howlong = when_to_retry - time(0);
if (howlong < 30)
howlong = 30;
warnx("%s: service unavailable; retrying in %d seconds",
https->http_hostname, howlong);
fs->fs_status = "waiting to retry";
sleep(howlong);
goto doretry;
}
if (errstr != 0) {
spewerror:
warnx("%s: %s: HTTP server returned error code %d",
fs->fs_outputfile, https->http_hostname, status);
if (fs->fs_verbose > 1) {
fputs(errstr, stderr);
fputc('\n', stderr);
html_display(remote);
}
free(errstr);
fclose(remote);
unsetup_sigalrm();
return EX_UNAVAILABLE;
}
if (redirection && new_location) {
fclose(remote);
if (base64ofmd5)
free(base64ofmd5);
fs->fs_status = "processing redirection";
status = http_redirect(fs, new_location, redirection == 301);
free(new_location);
return status;
} else if (redirection) {
warnx("%s: redirection but no new location",
fs->fs_outputfile);
fclose(remote);
if (base64ofmd5)
free(base64ofmd5);
return EX_PROTOCOL;
}
fs->fs_status = "retrieving file from HTTP/1.x server";
/*
* OK, if we got here, then we have finished parsing the header
* and have read the `\r\n' line which denotes the end of same.
* We may or may not have a good idea of the length of the file
* or its modtime. At this point we will have to deal with
* any special byte-range, content-negotiation, redirection,
* or authentication, and probably jump back up to the top,
* once we implement those features. So, all we have left to
* do is open up the output file and copy data from input to
* output until EOF.
*/
if (to_stdout)
local = fopen("/dev/stdout", restarting ? "a" : "w");
else
local = fopen(fs->fs_outputfile, restarting ? "a" : "w");
if (local == 0) {
warn("%s: fopen", fs->fs_outputfile);
fclose(remote);
unsetup_sigalrm();
return EX_OSERR;
}
fs->fs_modtime = last_modified;
fseek(local, restart_from, SEEK_SET); /* XXX truncation off_t->long */
display(fs, total_length, restart_from); /* XXX truncation */
if (chunked)
status = http_suck_chunked(fs, remote, local, total_length,
timo);
else
status = http_suck(fs, remote, local, total_length, timo);
if (status)
goto out;
status = errno; /* save errno for warn(), below, if needed */
display(fs, total_length, -1); /* do here in case we have to warn */
errno = status;
if (ferror(remote)) {
warn("reading remote file from %s", https->http_hostname);
status = EX_OSERR;
} else if(ferror(local)) {
warn("`%s': fwrite", fs->fs_outputfile);
status = EX_OSERR;
} else {
status = 0;
}
if (base64ofmd5) {
/*
* Ack. When restarting, the MD5 only covers the parts
* we are getting, not the whole thing.
*/
fseek(local, restart_from, SEEK_SET);
fs->fs_status = "computing MD5 message digest";
status = check_md5(local, base64ofmd5);
free(base64ofmd5);
}
fclose(local);
out:
unsetup_sigalrm();
fclose(remote);
if (status != 0)
rm(fs);
else
adjmodtime(fs);
return status;
#undef addstr
cantauth:
warnx("%s: cannot authenticate with %s %s",
fs->fs_outputfile,
(autherror == 401) ? "server" : "proxy",
https->http_hostname);
status = EX_NOPERM;
goto out;
}
/*
* Suck over an HTTP body in standard form.
*/
static int
http_suck(struct fetch_state *fs, FILE *remote, FILE *local,
off_t total_length, int timo)
{
static char buf[BUFFER_SIZE];
ssize_t readresult, writeresult;
do {
alarm(timo);
readresult = fread(buf, 1, sizeof buf, remote);
alarm(0);
if (readresult == 0)
return 0;
display(fs, total_length, readresult);
writeresult = fwrite(buf, 1, readresult, local);
} while (writeresult == readresult);
return 0;
}
/*
* Suck over an HTTP body in chunked form. Ick.
* Note that the return value convention here is a bit strange.
* A zero return does not necessarily mean success; rather, it means
* that this routine has already taken care of error reporting and
* just wants to exit.
*/
static int
http_suck_chunked(struct fetch_state *fs, FILE *remote, FILE *local,
off_t total_length, int timo)
{
static char buf[BUFFER_SIZE];
ssize_t readresult, writeresult;
size_t linelen;
u_long chunklen;
char *line, *ep;
for (;;) {
alarm(timo);
line = fgetln(remote, &linelen);
alarm(0);
if (line == 0) {
warnx("%s: error processing chunked encoding: "
"missing length", fs->fs_outputfile);
return EX_PROTOCOL;
}
line[--linelen] = '\0';
for (; linelen > 0; linelen--) {
if (isspace(line[linelen - 1]))
line[linelen - 1] = '\0';
}
errno = 0;
chunklen = strtoul(line, &ep, 16);
if (errno || *line == 0
|| (*ep && !isspace(*ep) && *ep != ';')) {
warnx("%s: error processing chunked encoding: "
"uninterpretable length: %s", line);
return EX_PROTOCOL;
}
if (chunklen == 0)
break;
#ifndef MIN
#define MIN(a,b) ((a)>(b)?(b):(a))
#endif
while (chunklen > 0) {
alarm(timo);
readresult = fread(buf, 1, MIN(sizeof buf, chunklen),
remote);
alarm(0);
if (readresult == 0) {
warnx("%s: EOF with %lu left in chunk",
fs->fs_outputfile, chunklen);
return EX_PROTOCOL;
}
display(fs, total_length, readresult);
chunklen -= readresult;
writeresult = fwrite(buf, 1, readresult, local);
if (writeresult != readresult)
return 0; /* main code will diagnose */
}
/*
* Read the bogus CRLF after the chunk's body.
*/
alarm(timo);
fread(buf, 1, 2, remote);
alarm(0);
}
/*
* If we got here, then we successfully read every chunk and got
* the end-of-chunks indicator. Now we have to ignore any trailer
* lines which come across---or we would if we cared about keeping
* the connection open. Since we are just going to close it anyway,
* we won't bother with that here. If ever something important is
* defined for the trailer, we will have to revisit that decision.
*/
return 0;
}
/*
* The format of the response line for an HTTP request is:
* HTTP/V.vv{WS}999{WS}Explanatory text for humans to read\r\n
* Old pre-HTTP/1.0 servers can return
* HTTP{WS}999{WS}Explanatory text for humans to read\r\n
* Where {WS} represents whitespace (spaces and/or tabs) and 999
* is a machine-interprable result code. We return the integer value
* of that result code, or the impossible value `0' if we are unable to
* parse the result.
*/
static int
http_first_line(const char *line)
{
char *ep;
unsigned long ul;
if (strncasecmp(line, "http", 4) != 0)
return 0;
line += 4;
while (*line && !isspace(*line)) /* skip non-whitespace */
line++;
while (*line && isspace(*line)) /* skip first whitespace */
line++;
errno = 0;
ul = strtoul(line, &ep, 10);
if (errno != 0 || ul > 999 || ul < 100 || !isspace(*ep))
return 0;
return ul;
}
/*
* The format of a header line for an HTTP request is:
* Header-Name: header-value (with comments in parens)\r\n
* This would be a nice application for gperf(1), except that the
* names are case-insensitive and gperf can't handle that.
*/
static enum http_header
http_parse_header(char *line, char **valuep)
{
char *colon, *value;
if (*line == '\0' /* protocol error! */
|| (line[0] == '\r' && line[1] == '\0'))
return ht_end_of_header;
colon = strchr(line, ':');
if (colon == 0)
return ht_syntax_error;
*colon = '\0';
for (value = colon + 1; *value && isspace(*value); value++)
; /* do nothing */
/* Trim trailing whitespace (including \r). */
*valuep = value;
value += strlen(value) - 1;
while (value > *valuep && isspace(*value))
value--;
*++value = '\0';
#define cmp(name, num) do { if (!strcasecmp(line, name)) return num; } while(0)
cmp("Accept-Ranges", ht_accept_ranges);
cmp("Age", ht_age);
cmp("Allow", ht_allow);
cmp("Cache-Control", ht_cache_control);
cmp("Connection", ht_connection);
cmp("Content-Base", ht_content_base);
cmp("Content-Encoding", ht_content_encoding);
cmp("Content-Language", ht_content_language);
cmp("Content-Length", ht_content_length);
cmp("Content-Location", ht_content_location);
cmp("Content-MD5", ht_content_md5);
cmp("Content-Range", ht_content_range);
cmp("Content-Type", ht_content_type);
cmp("Date", ht_date);
cmp("ETag", ht_etag);
cmp("Expires", ht_expires);
cmp("Last-Modified", ht_last_modified);
cmp("Location", ht_location);
cmp("Pragma", ht_pragma);
cmp("Proxy-Authenticate", ht_proxy_authenticate);
cmp("Public", ht_public);
cmp("Retry-After", ht_retry_after);
cmp("Server", ht_server);
cmp("Transfer-Encoding", ht_transfer_encoding);
cmp("Upgrade", ht_upgrade);
cmp("Vary", ht_vary);
cmp("Via", ht_via);
cmp("WWW-Authenticate", ht_www_authenticate);
cmp("Warning", ht_warning);
#undef cmp
return ht_unknown;
}
/*
* Compute the RSA Data Security, Inc., MD5 Message Digest of the file
* given in `fp', see if it matches the one given in base64 encoding by
* `base64ofmd5'. Warn and return an error if it doesn't.
*/
static int
check_md5(FILE *fp, char *base64ofmd5) {
MD5_CTX ctx;
unsigned char digest[16];
char buf[512];
size_t len;
char *ourval;
MD5Init(&ctx);
while ((len = fread(buf, 1, sizeof buf, fp)) != 0) {
MD5Update(&ctx, buf, len);
}
MD5Final(digest, &ctx);
ourval = to_base64(digest, 16);
if (strcmp(ourval, base64ofmd5) != 0) {
warnx("MD5 digest mismatch: %s, should be %s", ourval,
base64ofmd5);
free(ourval);
return EX_DATAERR;
}
free(ourval);
return 0;
}
static const char *wkdays[] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char *months[] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct",
"Nov", "Dec"
};
/*
* Interpret one of the three possible formats for an HTTP date.
* All of them are really bogus; HTTP should use either ISO 8601
* or NTP timestamps. We make some attempt to accept a subset of 8601
* format. The three standard formats are all fixed-length subsets of their
* respective standards (except 8601, which puts all of the stuff we
* care about up front).
*/
static time_t
parse_http_date(char *string)
{
static struct tm tm; /* get good initialization */
time_t rv;
const char *tz;
int i;
/* 8601 has the shortest minimum length */
if (strlen(string) < 15)
return -1;
if (isdigit(*string)) {
/* ISO 8601: 19970127T134551stuffwedon'tcareabout */
for (i = 0; i < 15; i++) {
if (i != 8 && !isdigit(string[i]))
break;
}
if (i < 15)
return -1;
#define digit(x) (string[x] - '0')
tm.tm_year = (digit(0) * 1000
+ digit(1) * 100
+ digit(2) * 10
+ digit(3)) - 1900;
tm.tm_mon = digit(4) * 10 + digit(5) - 1;
tm.tm_mday = digit(6) * 10 + digit(7);
if (string[8] != 'T' && string[8] != 't' && string[8] != ' ')
return -1;
tm.tm_hour = digit(9) * 10 + digit(10);
tm.tm_min = digit(11) * 10 + digit(12);
tm.tm_sec = digit(13) * 10 + digit(14);
/* We don't care about the rest of the stuff after the secs. */
} else if (string[3] == ',') {
/* Mon, 27 Jan 1997 14:24:35 stuffwedon'tcareabout */
if (strlen(string) < 25)
return -1;
string += 5; /* skip over day-of-week */
if (!(isdigit(string[0]) && isdigit(string[1])))
return -1;
tm.tm_mday = digit(0) * 10 + digit(1);
for (i = 0; i < 12; i++) {
if (strncasecmp(months[i], &string[3], 3) == 0)
break;
}
if (i >= 12)
return -1;
tm.tm_mon = i;
if (sscanf(&string[7], "%d %d:%d:%d", &i, &tm.tm_hour,
&tm.tm_min, &tm.tm_sec) != 4)
return -1;
tm.tm_year = i - 1900;
} else if (string[3] == ' ') {
/* Mon Jan 27 14:25:20 1997 */
if (strlen(string) < 25)
return -1;
string += 4;
for (i = 0; i < 12; i++) {
if (strncasecmp(string, months[i], 3) == 0)
break;
}
if (i >= 12)
return -1;
tm.tm_mon = i;
if (sscanf(&string[4], "%d %d:%d:%d %u", &tm.tm_mday,
&tm.tm_hour, &tm.tm_min, &tm.tm_sec, &i)
!= 5)
return -1;
tm.tm_year = i - 1900;
} else {
/* Monday, 27-Jan-97 14:31:09 stuffwedon'tcareabout */
char *comma = strchr(string, ',');
char mname[4];
if (comma == 0)
return -1;
string = comma + 1;
if (strlen(string) < 19)
return -1;
string++;
mname[4] = '\0';
if (sscanf(string, "%d-%c%c%c-%d %d:%d:%d", &tm.tm_mday,
mname, mname + 1, mname + 2, &tm.tm_year,
&tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 8)
return -1;
for (i = 0; i < 12; i++) {
if (strcasecmp(months[i], mname))
break;
}
if (i >= 12)
return -1;
tm.tm_mon = i;
}
#undef digit
if (tm.tm_sec > 60 || tm.tm_min > 59 || tm.tm_hour > 23
|| tm.tm_mday > 31 || tm.tm_mon > 11)
return -1;
if (tm.tm_sec < 0 || tm.tm_min < 0 || tm.tm_hour < 0
|| tm.tm_mday < 0 || tm.tm_mon < 0 || tm.tm_year < 0)
return -1;
tz = getenv("TZ");
setenv("TZ", "UTC0", 1);
tzset();
rv = mktime(&tm);
if (tz)
setenv("TZ", tz, 1);
else
unsetenv("TZ");
return rv;
}
static char *
format_http_date(time_t when)
{
struct tm *tm;
static char buf[30];
tm = gmtime(&when);
if (tm == 0)
return 0;
#ifndef HTTP_DATE_ISO_8601
sprintf(buf, "%s, %02d %s %04d %02d:%02d:%02d GMT",
wkdays[tm->tm_wday], tm->tm_mday, months[tm->tm_mon],
tm->tm_year + 1900, tm->tm_hour, tm->tm_min, tm->tm_sec);
#else /* ISO 8601 */
sprintf(buf, "%04d%02d%02dT%02d%02d%02d+0000",
tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
#endif
return buf;
}
static char *
format_http_user_agent(void)
{
static char buf[128];
static int inited;
if (!inited) {
int mib[2];
char ostype[128], osrelease[128], machine[128];
size_t len;
mib[0] = CTL_KERN;
mib[1] = KERN_OSTYPE;
len = sizeof ostype;
if (sysctl(mib, 2, ostype, &len, 0, 0) < 0) {
warn("sysctl");
ostype[0] = '\0';
}
mib[1] = KERN_OSRELEASE;
len = sizeof osrelease;
if (sysctl(mib, 2, osrelease, &len, 0, 0) < 0) {
warn("sysctl");
osrelease[0] = '\0';
}
mib[0] = CTL_HW;
mib[1] = HW_MACHINE;
len = sizeof machine;
if (sysctl(mib, 2, machine, &len, 0, 0) < 0) {
warn("sysctl");
machine[0] = '\0';
}
snprintf(buf, sizeof buf,
"User-Agent: " FETCH_VERSION " %s/%s (%s)\r\n",
ostype, osrelease, machine);
}
return buf;
}
/*
* Parse a Content-Range return header from the server. RFC 2066 defines
* this header to have the format:
* Content-Range: bytes 12345-67890/123456
* Since we always ask for the whole rest of the file, we consider it an
* error if the reply doesn't claim to give it to us.
*/
static int
parse_http_content_range(char *orig, off_t *restart_from, off_t *total_length)
{
u_quad_t first, last, total;
char *ep;
if (strncasecmp(orig, "bytes", 5) != 0) {
warnx("unknown Content-Range unit: `%s'", orig);
return EX_PROTOCOL;
}
orig += 5;
while (*orig && isspace(*orig))
orig++;
errno = 0;
first = strtouq(orig, &ep, 10);
if (errno != 0 || *ep != '-') {
warnx("invalid Content-Range: `%s'", orig);
return EX_PROTOCOL;
}
last = strtouq(ep + 1, &ep, 10);
if (errno != 0 || *ep != '/' || last < first) {
warnx("invalid Content-Range: `%s'", orig);
return EX_PROTOCOL;
}
total = strtouq(ep + 1, &ep, 10);
if (errno != 0 || !(*ep == '\0' || isspace(*ep))) {
warnx("invalid Content-Range: `%s'", orig);
return EX_PROTOCOL;
}
if (last + 1 != total) {
warnx("HTTP server did not return requested Content-Range");
return EX_PROTOCOL;
}
*restart_from = first;
*total_length = last;
return 0;
}
/*
* Do HTTP authentication. We only do ``basic'' right now, but
* MD5 ought to be fairly easy. The hard part is actually teasing
* apart the header, which is fairly badly designed (so what else is
* new?).
*/
static char *
getauthparam(char *params, const char *name)
{
char *rv;
enum state { normal, quoted } state;
while (*params) {
if (strncasecmp(params, name, strlen(name)) == 0
&& params[strlen(name)] == '=')
break;
state = normal;
while (*params) {
if (state == normal && *params == ',')
break;
if (*params == '\"')
state = (state == quoted) ? normal : quoted;
if (*params == '\\' && params[1] != '\0')
params++;
params++;
}
}
if (*params == '\0')
return 0;
params += strlen(name) + 1;
rv = params;
state = normal;
while (*params) {
if (state == normal && *params == ',')
break;
if (*params == '\"')
state = (state == quoted) ? normal : quoted;
if (*params == '\\' && params[1] != '\0')
params++;
params++;
}
if (params[-1] == '\"')
params[-1] = '\0';
else
params[0] = '\0';
if (*rv == '\"')
rv++;
return rv;
}
static int
process_http_auth(struct fetch_state *fs, char *hdr, int autherr)
{
enum state { normal, quoted } state;
char *scheme, *params, *nscheme, *realm;
struct http_auth *ha;
do {
scheme = params = hdr;
/* Look for end of scheme name. */
while (*params && !isspace(*params))
params++;
if (*params == '\0')
return EX_PROTOCOL;
/* Null-terminate scheme and skip whitespace. */
while (*params && isspace(*params))
*params++ = '\0';
/* Semi-parse parameters to find their end. */
nscheme = params;
state = normal;
while (*nscheme) {
if (state == normal && isspace(*nscheme))
break;
if (*nscheme == '\"')
state = (state == quoted) ? normal : quoted;
if (*nscheme == '\\' && nscheme[1] != '\0')
nscheme++;
nscheme++;
}
/* Null-terminate parameters and skip whitespace. */
while (*nscheme && isspace(*nscheme))
*nscheme++ = '\0';
realm = getauthparam(params, "realm");
if (realm == 0) {
scheme = nscheme;
continue;
}
if (autherr == 401)
ha = find_http_auth(&http_auth, scheme, realm);
else
ha = find_http_auth(&http_proxy_auth, scheme, realm);
if (ha)
return ha->ha_ham->ham_doauth(fs, ha, autherr == 407);
} while (*scheme);
return EX_NOPERM;
}
static void
parse_http_auth_env(const char *env, struct http_auth_head *ha_tqh)
{
char *nenv, *p, *scheme, *realm, *params;
struct http_auth *ha;
struct http_auth_method *ham;
nenv = alloca(strlen(env) + 1);
strcpy(nenv, env);
while ((p = strsep(&nenv, " \t")) != 0) {
scheme = strsep(&p, ":");
if (scheme == 0 || *scheme == '\0')
continue;
realm = strsep(&p, ":");
if (realm == 0 || *realm == '\0')
continue;
params = (p && *p) ? p : 0;
for (ham = http_auth_methods; ham->ham_scheme; ham++) {
if (strcasecmp(scheme, ham->ham_scheme) == 0)
break;
}
if (ham == 0)
continue;
ha = safe_malloc(sizeof *ha);
ha->ha_scheme = safe_strdup(scheme);
ha->ha_realm = safe_strdup(realm);
ha->ha_params = params ? safe_strdup(params) : 0;
ha->ha_ham = ham;
TAILQ_INSERT_TAIL(ha_tqh, ha, ha_link);
}
}
/*
* Look up an authentication method. Automatically clone wildcards
* into fully-specified entries.
*/
static struct http_auth *
find_http_auth(struct http_auth_head *tqh, const char *scm, const char *realm)
{
struct http_auth *ha;
for (ha = tqh->tqh_first; ha; ha = ha->ha_link.tqe_next) {
if (strcasecmp(ha->ha_scheme, scm) == 0
&& strcasecmp(ha->ha_realm, realm) == 0)
return ha;
}
for (ha = tqh->tqh_first; ha; ha = ha->ha_link.tqe_next) {
if (strcasecmp(ha->ha_scheme, scm) == 0
&& strcmp(ha->ha_realm, "*") == 0)
break;
}
if (ha != 0) {
struct http_auth *ha2;
ha2 = safe_malloc(sizeof *ha2);
ha2->ha_scheme = safe_strdup(scm);
ha2->ha_realm = safe_strdup(realm);
ha2->ha_params = ha->ha_params ? safe_strdup(ha->ha_params) :0;
ha2->ha_ham = ha->ha_ham;
TAILQ_INSERT_TAIL(tqh, ha2, ha_link);
ha = ha2;
}
return ha;
}
static void
setup_http_auth(void)
{
const char *envar;
static int once;
if (once)
return;
once = 1;
TAILQ_INIT(&http_auth);
TAILQ_INIT(&http_proxy_auth);
envar = getenv("HTTP_AUTH");
if (envar)
parse_http_auth_env(envar, &http_auth);
envar = getenv("HTTP_PROXY_AUTH");
if (envar)
parse_http_auth_env(envar, &http_proxy_auth);
}
static int
basic_doauth(struct fetch_state *fs, struct http_auth *ha, int isproxy)
{
struct http_state *https = fs->fs_proto;
char *user;
char *pass;
char *enc;
char **hdr;
size_t userlen;
FILE *fp;
if (!isatty(0) &&
(ha->ha_params == 0 || strchr(ha->ha_params, ':') == 0))
return EX_NOPERM;
fp = fopen("/dev/tty", "r+");
if (fp == 0) {
warn("opening /dev/tty");
return EX_OSERR;
}
if (ha->ha_params == 0) {
fprintf(fp, "Enter `basic' user name for realm `%s': ",
ha->ha_realm);
fflush(fp);
user = fgetln(stdin, &userlen);
if (user == 0 || userlen < 1) { /* longer name? */
fclose(fp);
return EX_NOPERM;
}
if (user[userlen - 1] == '\n')
user[userlen - 1] = '\0';
else
user[userlen] = '\0';
user = safe_strdup(user);
pass = 0;
} else if ((pass = strchr(ha->ha_params, ':')) == 0) {
user = safe_strdup(ha->ha_params);
free(ha->ha_params);
}
if (pass == 0) {
pass = getpass("Password: ");
ha->ha_params = safe_malloc(strlen(user) + 2 + strlen(pass));
strcpy(ha->ha_params, user);
strcat(ha->ha_params, ":");
strcat(ha->ha_params, pass);
}
enc = to_base64(ha->ha_params, strlen(ha->ha_params));
hdr = isproxy ? &https->http_proxy_authentication
: &https->http_authentication;
if (*hdr)
free(*hdr);
*hdr = safe_malloc(sizeof("Proxy-Authorization: basic \r\n")
+ strlen(enc));
if (isproxy)
strcpy(*hdr, "Proxy-Authorization");
else
strcpy(*hdr, "Authorization");
strcat(*hdr, ": Basic ");
strcat(*hdr, enc);
strcat(*hdr, "\r\n");
free(enc);
return 0;
}
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