commit a104b98d48c0d5cfa5dcc79175f0ffa853ec4528
Author: Simon Howard <fraggle@soulsphere.org>
AuthorDate: Wed Sep 27 23:37:46 2017 -0400
Commit: Simon Howard <fraggle@soulsphere.org>
CommitDate: Wed Sep 27 23:37:46 2017 -0400
net: Get rid of NET_SafePuts().
Instead what's almost always wanted is to read a "safe" string that
cannot contain any control codes. So introduce NET_ReadSafeString()
instead as a wrapper around NET_ReadString() that does this.
---
src/net_client.c | 8 +++-----
src/net_common.c | 5 ++---
src/net_packet.c | 32 ++++++++++++++++++++++++++++++++
src/net_packet.h | 1 +
src/net_query.c | 2 +-
src/net_server.c | 4 ++--
src/net_structrw.c | 24 ++----------------------
src/net_structrw.h | 2 --
8 files changed, 43 insertions(+), 35 deletions(-)
diff --git a/src/net_client.c b/src/net_client.c
index 6f558604..11615c08 100644
--- a/src/net_client.c
+++ b/src/net_client.c
@@ -433,7 +433,7 @@ static void NET_CL_ParseSYN(net_packet_t *packet)
net_protocol_t protocol;
char *server_version;
- server_version = NET_ReadString(packet);
+ server_version = NET_ReadSafeString(packet);
if (server_version == NULL)
{
return;
@@ -830,16 +830,14 @@ static void NET_CL_ParseConsoleMessage(net_packet_t *packet)
{
char *msg;
- msg = NET_ReadString(packet);
+ msg = NET_ReadSafeString(packet);
if (msg == NULL)
{
return;
}
- printf("Message from server: ");
-
- NET_SafePuts(msg);
+ printf("Message from server:\n%s\n", msg);
}
// parse a received packet
diff --git a/src/net_common.c b/src/net_common.c
index 78520c5f..ca194d80 100644
--- a/src/net_common.c
+++ b/src/net_common.c
@@ -132,7 +132,7 @@ static void NET_Conn_ParseReject(net_connection_t *conn, net_packet_t *packet)
{
char *msg;
- msg = NET_ReadString(packet);
+ msg = NET_ReadSafeString(packet);
if (msg == NULL)
{
@@ -146,8 +146,7 @@ static void NET_Conn_ParseReject(net_connection_t *conn, net_packet_t *packet)
conn->state = NET_CONN_STATE_DISCONNECTED;
conn->disconnect_reason = NET_DISCONNECT_REMOTE;
- printf("Rejected by server: ");
- NET_SafePuts(msg);
+ printf("Rejected by server: %s\n", msg);
}
}
diff --git a/src/net_packet.c b/src/net_packet.c
index 82a20fe5..ae1be7cb 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -15,6 +15,7 @@
// Network packet manipulation (net_packet_t)
//
+#include <ctype.h>
#include <string.h>
#include "m_misc.h"
#include "net_packet.h"
@@ -202,6 +203,37 @@ char *NET_ReadString(net_packet_t *packet)
return start;
}
+// Read a string from the packet, but (potentially) modify it to strip
+// out any unprintable characters which could be malicious control codes.
+// Note that this may modify the original packet contents.
+char *NET_ReadSafeString(net_packet_t *packet)
+{
+ char *r, *w, *result;
+
+ result = NET_ReadString(packet);
+ if (result == NULL)
+ {
+ return NULL;
+ }
+
+ // w is always <= r, so we never produce a longer string than the original.
+ w = result;
+ for (r = result; *r != '\0'; ++r)
+ {
+ // TODO: This is a very naive way of producing a safe string; only
+ // ASCII characters are allowed. Probably this should really support
+ // UTF-8 characters as well.
+ if (isprint(*r) || *r == '\n')
+ {
+ *w = *r;
+ ++w;
+ }
+ }
+ *w = '\0';
+
+ return result;
+}
+
// Dynamically increases the size of a packet
static void NET_IncreasePacket(net_packet_t *packet)
diff --git a/src/net_packet.h b/src/net_packet.h
index ced4e435..011f1af9 100644
--- a/src/net_packet.h
+++ b/src/net_packet.h
@@ -33,6 +33,7 @@ boolean NET_ReadSInt16(net_packet_t *packet, signed int *data);
boolean NET_ReadSInt32(net_packet_t *packet, signed int *data);
char *NET_ReadString(net_packet_t *packet);
+char *NET_ReadSafeString(net_packet_t *packet);
void NET_WriteInt8(net_packet_t *packet, unsigned int i);
void NET_WriteInt16(net_packet_t *packet, unsigned int i);
diff --git a/src/net_query.c b/src/net_query.c
index eaa6f96d..94fdf03b 100644
--- a/src/net_query.c
+++ b/src/net_query.c
@@ -738,7 +738,7 @@ static void NET_QueryPrintCallback(net_addr_t *addr,
printf("(game running) ");
}
- NET_SafePuts(data->description);
+ printf("%s\n", data->description);
}
void NET_LANQuery(void)
diff --git a/src/net_server.c b/src/net_server.c
index fa31cbcf..ab79b954 100644
--- a/src/net_server.c
+++ b/src/net_server.c
@@ -213,7 +213,7 @@ static void NET_SV_BroadcastMessage(char *s, ...)
va_start(args, s);
M_vsnprintf(buf, sizeof(buf), s, args);
va_end(args);
-
+
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
@@ -222,7 +222,7 @@ static void NET_SV_BroadcastMessage(char *s, ...)
}
}
- NET_SafePuts(buf);
+ printf("%s\n", buf);
}
diff --git a/src/net_structrw.c b/src/net_structrw.c
index a820df5f..6d958cf9 100644
--- a/src/net_structrw.c
+++ b/src/net_structrw.c
@@ -17,7 +17,6 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <ctype.h>
#include "doomtype.h"
#include "m_misc.h"
@@ -122,7 +121,7 @@ boolean NET_ReadQueryData(net_packet_t *packet, net_querydata_t *query)
{
boolean result;
- query->version = NET_ReadString(packet);
+ query->version = NET_ReadSafeString(packet);
result = query->version != NULL
&& NET_ReadInt8(packet, (unsigned int *) &query->server_state)
@@ -133,7 +132,7 @@ boolean NET_ReadQueryData(net_packet_t *packet, net_querydata_t *query)
if (result)
{
- query->description = NET_ReadString(packet);
+ query->description = NET_ReadSafeString(packet);
return query->description != NULL;
}
@@ -551,22 +550,3 @@ void NET_WritePRNGSeed(net_packet_t *packet, prng_seed_t seed)
NET_WriteBlob(packet, seed, sizeof(prng_seed_t));
}
-// "Safe" version of puts, for displaying messages received from the
-// network.
-
-void NET_SafePuts(char *s)
-{
- char *p;
-
- // Do not do a straight "puts" of the string, as this could be
- // dangerous (sending control codes to terminals can do all
- // kinds of things)
-
- for (p=s; *p; ++p)
- {
- if (isprint(*p) || *p == '\n')
- putchar(*p);
- }
-
- putchar('\n');
-}
diff --git a/src/net_structrw.h b/src/net_structrw.h
index f02f169a..e349127c 100644
--- a/src/net_structrw.h
+++ b/src/net_structrw.h
@@ -43,8 +43,6 @@ void NET_WriteSHA1Sum(net_packet_t *packet, sha1_digest_t digest);
void NET_WriteWaitData(net_packet_t *packet, net_waitdata_t *data);
boolean NET_ReadWaitData(net_packet_t *packet, net_waitdata_t *data);
-void NET_SafePuts(char *msg);
-
boolean NET_ReadPRNGSeed(net_packet_t *packet, prng_seed_t seed);
void NET_WritePRNGSeed(net_packet_t *packet, prng_seed_t seed);