wget: fix for brain-damaged HTTP servers. Closes 9471

write(3, "GET / HTTP/1.1\r\nUser-Agent: Wget\r\nConnection: close\r\n\r\n", 74) = 74
shutdown(3, SHUT_WR)    = 0
alarm(900)              = 900
read(3, "", 1024)       = 0
write(2, "wget: error getting response\n", 29) = 29
exit(1)

The peer simply does not return anything. It closes its connection.

Probably it detects wget closing its writing end: shutdown(3, SHUT_WR).

The point it, closing write side of the socket is _valid_ for HTTP.
wget sent the full request, it won't be sending anything more:
it will only receive the response, and that's it.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-01-11 20:16:45 +01:00
parent 098b713c7b
commit a6f8651911

View File

@ -137,6 +137,8 @@
#endif
#define SSL_SUPPORTED (ENABLE_FEATURE_WGET_OPENSSL || ENABLE_FEATURE_WGET_SSL_HELPER)
struct host_info {
char *allocated;
const char *path;
@ -147,7 +149,7 @@ struct host_info {
};
static const char P_FTP[] ALIGN1 = "ftp";
static const char P_HTTP[] ALIGN1 = "http";
#if ENABLE_FEATURE_WGET_OPENSSL || ENABLE_FEATURE_WGET_SSL_HELPER
#if SSL_SUPPORTED
static const char P_HTTPS[] ALIGN1 = "https";
#endif
@ -448,7 +450,7 @@ static void parse_url(const char *src_url, struct host_info *h)
if (strcmp(url, P_FTP) == 0) {
h->port = bb_lookup_port(P_FTP, "tcp", 21);
} else
#if ENABLE_FEATURE_WGET_OPENSSL || ENABLE_FEATURE_WGET_SSL_HELPER
#if SSL_SUPPORTED
if (strcmp(url, P_HTTPS) == 0) {
h->port = bb_lookup_port(P_HTTPS, "tcp", 443);
h->protocol = P_HTTPS;
@ -1089,12 +1091,17 @@ static void download_one_url(const char *url)
}
fflush(sfp);
/* If we use SSL helper, keeping our end of the socket open for writing
* makes our end (i.e. the same fd!) readable (EAGAIN instead of EOF)
* even after child closes its copy of the fd.
* This helps:
*/
shutdown(fileno(sfp), SHUT_WR);
#if SSL_SUPPORTED
if (target.protocol == P_HTTPS) {
/* If we use SSL helper, keeping our end of the socket open for writing
* makes our end (i.e. the same fd!) readable (EAGAIN instead of EOF)
* even after child closes its copy of the fd.
* This helps:
*/
shutdown(fileno(sfp), SHUT_WR);
}
#endif
/*
* Retrieve HTTP response line and check for "200" status code.