From 1f02bd2e66d7d27c6c1a137eaf86a2337d867b55 Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Thu, 15 Sep 2016 02:54:32 +0800
Subject: [PATCH] lws_snprintf
Thanks to Fabrice Gilot for reporting the problem that led to uncovering this.
Due to a misunderstanding of the return value of snprintf (it is not truncated according
to the max size passed in) in several places relying on snprintf to truncate the length
overflows are possible.
This patch wraps snprintf with a new lws_snprintf() which does truncate its length to allow
the buffer limiting scheme to work properly.
All users should update with these fixes.
---
lib/client-handshake.c | 26 +++++-----
lib/libuv.c | 6 +--
lib/libwebsockets.c | 88 +++++++++++++++++++-------------
lib/libwebsockets.h | 16 +++++-
lib/lws-plat-unix.c | 6 +--
lib/private-libwebsockets.h | 2 +-
lib/server.c | 12 ++---
libwebsockets-api-doc.html | 24 +++++++++
lwsws/conf.c | 12 ++---
plugins/protocol_lws_status.c | 4 +-
test-server/test-fraggle.c | 2 +-
test-server/test-ping.c | 2 +-
test-server/test-server-status.c | 4 +-
13 files changed, 130 insertions(+), 74 deletions(-)
diff --git a/lib/client-handshake.c b/lib/client-handshake.c
index 6892f5d1..35e296a1 100644
--- a/lib/client-handshake.c
+++ b/lib/client-handshake.c
@@ -366,7 +366,7 @@ html_parser_cb(const hubbub_token *token, void *pw)
switch (token->type) {
case HUBBUB_TOKEN_DOCTYPE:
- p += snprintf(p, end - p, "<!DOCTYPE %.*s %s ",
+ p += lws_snprintf(p, end - p, "<!DOCTYPE %.*s %s ",
(int) token->data.doctype.name.len,
token->data.doctype.name.ptr,
token->data.doctype.force_quirks ?
@@ -375,20 +375,20 @@ html_parser_cb(const hubbub_token *token, void *pw)
if (token->data.doctype.public_missing)
printf("\tpublic: missing\n");
else
- p += snprintf(p, end - p, "PUBLIC \"%.*s\"\n",
+ p += lws_snprintf(p, end - p, "PUBLIC \"%.*s\"\n",
(int) token->data.doctype.public_id.len,
token->data.doctype.public_id.ptr);
if (token->data.doctype.system_missing)
printf("\tsystem: missing\n");
else
- p += snprintf(p, end - p, " \"%.*s\">\n",
+ p += lws_snprintf(p, end - p, " \"%.*s\">\n",
(int) token->data.doctype.system_id.len,
token->data.doctype.system_id.ptr);
break;
case HUBBUB_TOKEN_START_TAG:
- p += snprintf(p, end - p, "<%.*s", (int)token->data.tag.name.len,
+ p += lws_snprintf(p, end - p, "<%.*s", (int)token->data.tag.name.len,
token->data.tag.name.ptr);
/* (token->data.tag.self_closing) ?
@@ -408,23 +408,23 @@ html_parser_cb(const hubbub_token *token, void *pw)
pp += r->from_len;
plen -= r->from_len;
}
- p += snprintf(p, end - p, " %.*s=\"%s/%.*s\"",
+ p += lws_snprintf(p, end - p, " %.*s=\"%s/%.*s\"",
(int) token->data.tag.attributes[i].name.len,
token->data.tag.attributes[i].name.ptr,
r->to, plen, pp);
} else
- p += snprintf(p, end - p, " %.*s=\"%.*s\"",
+ p += lws_snprintf(p, end - p, " %.*s=\"%.*s\"",
(int) token->data.tag.attributes[i].name.len,
token->data.tag.attributes[i].name.ptr,
(int) token->data.tag.attributes[i].value.len,
token->data.tag.attributes[i].value.ptr);
}
- p += snprintf(p, end - p, ">\n");
+ p += lws_snprintf(p, end - p, ">\n");
break;
case HUBBUB_TOKEN_END_TAG:
- p += snprintf(p, end - p, "</%.*s", (int) token->data.tag.name.len,
+ p += lws_snprintf(p, end - p, "</%.*s", (int) token->data.tag.name.len,
token->data.tag.name.ptr);
/*
(token->data.tag.self_closing) ?
@@ -433,25 +433,25 @@ html_parser_cb(const hubbub_token *token, void *pw)
"attributes:" : "");
*/
for (i = 0; i < token->data.tag.n_attributes; i++) {
- p += snprintf(p, end - p, " %.*s='%.*s'\n",
+ p += lws_snprintf(p, end - p, " %.*s='%.*s'\n",
(int) token->data.tag.attributes[i].name.len,
token->data.tag.attributes[i].name.ptr,
(int) token->data.tag.attributes[i].value.len,
token->data.tag.attributes[i].value.ptr);
}
- p += snprintf(p, end - p, ">\n");
+ p += lws_snprintf(p, end - p, ">\n");
break;
case HUBBUB_TOKEN_COMMENT:
- p += snprintf(p, end - p, "<!-- %.*s -->\n",
+ p += lws_snprintf(p, end - p, "<!-- %.*s -->\n",
(int) token->data.comment.len,
token->data.comment.ptr);
break;
case HUBBUB_TOKEN_CHARACTER:
- p += snprintf(p, end - p, "%.*s", (int) token->data.character.len,
+ p += lws_snprintf(p, end - p, "%.*s", (int) token->data.character.len,
token->data.character.ptr);
break;
case HUBBUB_TOKEN_EOF:
- p += snprintf(p, end - p, "\n");
+ p += lws_snprintf(p, end - p, "\n");
break;
}
diff --git a/lib/libuv.c b/lib/libuv.c
index 64e5a7ed..bb1bee30 100644
--- a/lib/libuv.c
+++ b/lib/libuv.c
@@ -484,14 +484,14 @@ lws_plat_plugins_init(struct lws_context * context, const char * const *d)
lwsl_notice(" %s\n", dent.name);
- snprintf(path, sizeof(path) - 1, "%s/%s", *d, dent.name);
+ lws_snprintf(path, sizeof(path) - 1, "%s/%s", *d, dent.name);
if (uv_dlopen(path, &lib)) {
uv_dlerror(&lib);
lwsl_err("Error loading DSO: %s\n", lib.errmsg);
goto bail;
}
/* we could open it, can we get his init function? */
- m = snprintf(path, sizeof(path) - 1, "init_%s",
+ m = lws_snprintf(path, sizeof(path) - 1, "init_%s",
dent.name + 3 /* snip lib... */);
path[m - 3] = '\0'; /* snip the .so */
if (uv_dlsym(&lib, path, &v)) {
@@ -554,7 +554,7 @@ lws_plat_plugins_destroy(struct lws_context * context)
while (plugin) {
p = plugin;
- m = snprintf(path, sizeof(path) - 1, "destroy_%s", plugin->name + 3);
+ m = lws_snprintf(path, sizeof(path) - 1, "destroy_%s", plugin->name + 3);
path[m - 3] = '\0';
if (uv_dlsym(&plugin->lib, path, &v)) {
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index f62c1561..85622903 100755
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -1165,7 +1165,7 @@ lwsl_timestamp(int level, char *p, int len)
continue;
now = time_in_microseconds() / 100;
if (ptm)
- n = snprintf(p, len,
+ n = lws_snprintf(p, len,
"[%04d/%02d/%02d %02d:%02d:%02d:%04d] %s: ",
ptm->tm_year + 1900,
ptm->tm_mon + 1,
@@ -1175,7 +1175,7 @@ lwsl_timestamp(int level, char *p, int len)
ptm->tm_sec,
(int)(now % 10000), log_level_names[n]);
else
- n = snprintf(p, len, "[%llu:%04d] %s: ",
+ n = lws_snprintf(p, len, "[%llu:%04d] %s: ",
(unsigned long long) now / 10000,
(int)(now % 10000), log_level_names[n]);
return n;
@@ -1683,6 +1683,24 @@ lws_finalize_startup(struct lws_context *context)
return 0;
}
+int
+lws_snprintf(char *str, size_t size, const char *format, ...)
+{
+ va_list ap;
+ int n;
+
+ if (!size)
+ return 0;
+
+ va_start(ap, format);
+ n = vsnprintf(str, size, format, ap);
+ va_end(ap);
+
+ if (n >= size)
+ return size;
+
+ return n;
+}
LWS_VISIBLE LWS_EXTERN int
lws_is_cgi(struct lws *wsi) {
@@ -1831,7 +1849,7 @@ lws_cgi(struct lws *wsi, const char * const *exec_array, int script_uri_path_len
if (wsi->u.hdr.ah) {
if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
uritok = WSI_TOKEN_POST_URI;
- snprintf(cgi_path, sizeof(cgi_path) - 1, "REQUEST_URI=%s",
+ lws_snprintf(cgi_path, sizeof(cgi_path) - 1, "REQUEST_URI=%s",
lws_hdr_simple_ptr(wsi, uritok));
cgi_path[sizeof(cgi_path) - 1] = '\0';
env_array[n++] = cgi_path;
@@ -1841,7 +1859,7 @@ lws_cgi(struct lws *wsi, const char * const *exec_array, int script_uri_path_len
env_array[n++] = "REQUEST_METHOD=GET";
env_array[n++] = p;
- p += snprintf(p, end - p, "QUERY_STRING=");
+ p += lws_snprintf(p, end - p, "QUERY_STRING=");
/* dump the individual URI Arg parameters */
m = 0;
while (1) {
@@ -1866,55 +1884,55 @@ lws_cgi(struct lws *wsi, const char * const *exec_array, int script_uri_path_len
*p++ = '\0';
env_array[n++] = p;
- p += snprintf(p, end - p, "PATH_INFO=%s",
+ p += lws_snprintf(p, end - p, "PATH_INFO=%s",
lws_hdr_simple_ptr(wsi, uritok) +
script_uri_path_len);
p++;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_REFERER)) {
env_array[n++] = p;
- p += snprintf(p, end - p, "HTTP_REFERER=%s",
+ p += lws_snprintf(p, end - p, "HTTP_REFERER=%s",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_REFERER));
p++;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_HOST)) {
env_array[n++] = p;
- p += snprintf(p, end - p, "HTTP_HOST=%s",
+ p += lws_snprintf(p, end - p, "HTTP_HOST=%s",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HOST));
p++;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COOKIE)) {
env_array[n++] = p;
- p += snprintf(p, end - p, "HTTP_COOKIE=%s",
+ p += lws_snprintf(p, end - p, "HTTP_COOKIE=%s",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_COOKIE));
p++;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_USER_AGENT)) {
env_array[n++] = p;
- p += snprintf(p, end - p, "USER_AGENT=%s",
+ p += lws_snprintf(p, end - p, "USER_AGENT=%s",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_USER_AGENT));
p++;
}
if (uritok == WSI_TOKEN_POST_URI) {
if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE)) {
env_array[n++] = p;
- p += snprintf(p, end - p, "CONTENT_TYPE=%s",
+ p += lws_snprintf(p, end - p, "CONTENT_TYPE=%s",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE));
p++;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_LENGTH)) {
env_array[n++] = p;
- p += snprintf(p, end - p, "CONTENT_LENGTH=%s",
+ p += lws_snprintf(p, end - p, "CONTENT_LENGTH=%s",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_CONTENT_LENGTH));
p++;
}
}
env_array[n++] = p;
- p += snprintf(p, end - p, "SCRIPT_PATH=%s", exec_array[0]) + 1;
+ p += lws_snprintf(p, end - p, "SCRIPT_PATH=%s", exec_array[0]) + 1;
while (mp_cgienv) {
env_array[n++] = p;
- p += snprintf(p, end - p, "%s=%s", mp_cgienv->name,
+ p += lws_snprintf(p, end - p, "%s=%s", mp_cgienv->name,
mp_cgienv->value);
lwsl_debug(" Applying mount-specific cgi env '%s'\n",
env_array[n - 1]);
@@ -2360,7 +2378,7 @@ lws_access_log(struct lws *wsi)
if (!p)
p = "";
- l = snprintf(ass, sizeof(ass) - 1, "%s %d %lu %s\n",
+ l = lws_snprintf(ass, sizeof(ass) - 1, "%s %d %lu %s\n",
wsi->access_log.header_log,
wsi->access_log.response, wsi->access_log.sent, p);
@@ -2403,7 +2421,7 @@ lws_json_dump_vhost(const struct lws_vhost *vh, char *buf, int len)
if (len < 100)
return 0;
- buf += snprintf(buf, end - buf,
+ buf += lws_snprintf(buf, end - buf,
"{\n \"name\":\"%s\",\n"
" \"port\":\"%d\",\n"
" \"use_ssl\":\"%d\",\n"
@@ -2429,11 +2447,11 @@ lws_json_dump_vhost(const struct lws_vhost *vh, char *buf, int len)
if (vh->mount_list) {
const struct lws_http_mount *m = vh->mount_list;
- buf += snprintf(buf, end - buf, ",\n \"mounts\":[");
+ buf += lws_snprintf(buf, end - buf, ",\n \"mounts\":[");
while (m) {
if (!first)
- buf += snprintf(buf, end - buf, ",");
- buf += snprintf(buf, end - buf,
+ buf += lws_snprintf(buf, end - buf, ",");
+ buf += lws_snprintf(buf, end - buf,
"\n {\n \"mountpoint\":\"%s\",\n"
" \"origin\":\"%s%s\",\n"
" \"cache_max_age\":\"%d\",\n"
@@ -2449,25 +2467,25 @@ lws_json_dump_vhost(const struct lws_vhost *vh, char *buf, int len)
m->cache_revalidate,
m->cache_intermediaries);
if (m->def)
- buf += snprintf(buf, end - buf,
+ buf += lws_snprintf(buf, end - buf,
",\n \"default\":\"%s\"",
m->def);
- buf += snprintf(buf, end - buf, "\n }");
+ buf += lws_snprintf(buf, end - buf, "\n }");
first = 0;
m = m->mount_next;
}
- buf += snprintf(buf, end - buf, "\n ]");
+ buf += lws_snprintf(buf, end - buf, "\n ]");
}
if (vh->protocols) {
n = 0;
first = 1;
- buf += snprintf(buf, end - buf, ",\n \"ws-protocols\":[");
+ buf += lws_snprintf(buf, end - buf, ",\n \"ws-protocols\":[");
while (n < vh->count_protocols) {
if (!first)
- buf += snprintf(buf, end - buf, ",");
- buf += snprintf(buf, end - buf,
+ buf += lws_snprintf(buf, end - buf, ",");
+ buf += lws_snprintf(buf, end - buf,
"\n {\n \"%s\":\{\n"
" \"status\":\"ok\"\n }\n }"
,
@@ -2475,10 +2493,10 @@ lws_json_dump_vhost(const struct lws_vhost *vh, char *buf, int len)
first = 0;
n++;
}
- buf += snprintf(buf, end - buf, "\n ]");
+ buf += lws_snprintf(buf, end - buf, "\n ]");
}
- buf += snprintf(buf, end - buf, "\n}");
+ buf += lws_snprintf(buf, end - buf, "\n}");
return buf - orig;
}
@@ -2497,7 +2515,7 @@ lws_json_dump_context(const struct lws_context *context, char *buf, int len)
time_t t = time(NULL);
int listening = 0, cgi_count = 0, n;
- buf += snprintf(buf, end - buf, "{ "
+ buf += lws_snprintf(buf, end - buf, "{ "
"\"version\":\"%s\",\n"
"\"uptime\":\"%ld\",\n"
"\"cgi_spawned\":\"%d\",\n"
@@ -2517,19 +2535,19 @@ lws_json_dump_context(const struct lws_context *context, char *buf, int len)
m = getloadavg(d, 3);
for (n = 0; n < m; n++) {
- buf += snprintf(buf, end - buf,
+ buf += lws_snprintf(buf, end - buf,
"\"l%d\":\"%.2f\",\n",
n + 1, d[n]);
}
}
#endif
- buf += snprintf(buf, end - buf, "\"pt\":[\n ");
+ buf += lws_snprintf(buf, end - buf, "\"pt\":[\n ");
for (n = 0; n < context->count_threads; n++) {
pt = &context->pt[n];
if (n)
- buf += snprintf(buf, end - buf, ",");
- buf += snprintf(buf, end - buf,
+ buf += lws_snprintf(buf, end - buf, ",");
+ buf += lws_snprintf(buf, end - buf,
"\n {\n"
" \"fds_count\":\"%d\",\n"
" \"ah_pool_inuse\":\"%d\",\n"
@@ -2540,7 +2558,7 @@ lws_json_dump_context(const struct lws_context *context, char *buf, int len)
pt->ah_wait_list_length);
}
- buf += snprintf(buf, end - buf, "], \"vhosts\":[\n ");
+ buf += lws_snprintf(buf, end - buf, "], \"vhosts\":[\n ");
while (vh) {
if (!first)
@@ -2553,7 +2571,7 @@ lws_json_dump_context(const struct lws_context *context, char *buf, int len)
vh = vh->vhost_next;
}
- buf += snprintf(buf, end - buf, "],\n\"listen_wsi\":\"%d\"",
+ buf += lws_snprintf(buf, end - buf, "],\n\"listen_wsi\":\"%d\"",
listening);
#ifdef LWS_WITH_CGI
@@ -2568,10 +2586,10 @@ lws_json_dump_context(const struct lws_context *context, char *buf, int len)
}
}
#endif
- buf += snprintf(buf, end - buf, ",\n \"cgi_alive\":\"%d\"\n ",
+ buf += lws_snprintf(buf, end - buf, ",\n \"cgi_alive\":\"%d\"\n ",
cgi_count);
- buf += snprintf(buf, end - buf, "}\n ");
+ buf += lws_snprintf(buf, end - buf, "}\n ");
return buf - orig;
}
diff --git a/lib/libwebsockets.h b/lib/libwebsockets.h
index ef9cd0f1..51830909 100644
--- a/lib/libwebsockets.h
+++ b/lib/libwebsockets.h
@@ -147,7 +147,7 @@ struct sockaddr_in;
#define LWS_O_RDONLY _O_RDONLY
#if !defined(_MSC_VER) || _MSC_VER < 1900 /* Visual Studio 2015 already defines this in <stdio.h> */
-#define snprintf _snprintf
+#define lws_snprintf _snprintf
#endif
#ifndef __func__
@@ -2190,6 +2190,20 @@ lws_ext_parse_options(const struct lws_extension *ext, struct lws *wsi,
LWS_VISIBLE LWS_EXTERN void
lws_set_allocator(void *(*realloc)(void *ptr, size_t size));
+/**
+ * lws_snprintf(): lws_snprintf that truncates the returned length too
+ *
+ * \param str: destination buffer
+ * \param size: bytes left in destination buffer
+ * \param format: format string
+ * \param ...: args for format
+ *
+ * This lets you correctly truncate buffers by concatenating lengths, if you
+ * reach the limit the reported length doesn't exceed the limit.
+ */
+LWS_VISIBLE LWS_EXTERN int
+lws_snprintf(char *str, size_t size, const char *format, ...);
+
#ifdef __cplusplus
}
#endif
diff --git a/lib/lws-plat-unix.c b/lib/lws-plat-unix.c
index e26b041f..b430a78c 100644
--- a/lib/lws-plat-unix.c
+++ b/lib/lws-plat-unix.c
@@ -331,7 +331,7 @@ lws_plat_plugins_init(struct lws_context * context, const char * const *d)
lwsl_notice(" %s\n", namelist[i]->d_name);
- snprintf(path, sizeof(path) - 1, "%s/%s", *d,
+ lws_snprintf(path, sizeof(path) - 1, "%s/%s", *d,
namelist[i]->d_name);
l = dlopen(path, RTLD_NOW);
if (!l) {
@@ -341,7 +341,7 @@ lws_plat_plugins_init(struct lws_context * context, const char * const *d)
goto bail;
}
/* we could open it, can we get his init function? */
- m = snprintf(path, sizeof(path) - 1, "init_%s",
+ m = lws_snprintf(path, sizeof(path) - 1, "init_%s",
namelist[i]->d_name + 3 /* snip lib... */);
path[m - 3] = '\0'; /* snip the .so */
initfunc = dlsym(l, path);
@@ -406,7 +406,7 @@ lws_plat_plugins_destroy(struct lws_context * context)
while (plugin) {
p = plugin;
- m = snprintf(path, sizeof(path) - 1, "destroy_%s", plugin->name + 3);
+ m = lws_snprintf(path, sizeof(path) - 1, "destroy_%s", plugin->name + 3);
path[m - 3] = '\0';
func = dlsym(plugin->l, path);
if (!func) {
diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 1a0792a0..8102a730 100644
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -97,7 +97,7 @@
#endif
#ifdef LWS_HAVE__SNPRINTF
-#define snprintf _snprintf
+#define lws_snprintf _snprintf
#endif
#else /* not windows --> */
diff --git a/lib/server.c b/lib/server.c
index 1ac36515..b7d5bf0b 100644
--- a/lib/server.c
+++ b/lib/server.c
@@ -301,7 +301,7 @@ lws_http_serve(struct lws *wsi, char *uri, const char *origin,
#endif
int n, spin = 0;
- snprintf(path, sizeof(path) - 1, "%s/%s", origin, uri);
+ lws_snprintf(path, sizeof(path) - 1, "%s/%s", origin, uri);
#ifndef _WIN32_WCE
do {
@@ -322,12 +322,12 @@ lws_http_serve(struct lws *wsi, char *uri, const char *origin,
}
sym[len] = '\0';
lwsl_debug("symlink %s -> %s\n", path, sym);
- snprintf(path, sizeof(path) - 1, "%s", sym);
+ lws_snprintf(path, sizeof(path) - 1, "%s", sym);
}
#endif
if ((S_IFMT & st.st_mode) == S_IFDIR) {
lwsl_debug("default filename append to dir\n");
- snprintf(path, sizeof(path) - 1, "%s/%s/index.html",
+ lws_snprintf(path, sizeof(path) - 1, "%s/%s/index.html",
origin, uri);
}
@@ -601,7 +601,7 @@ lws_http_action(struct lws *wsi)
else
me = "unknown";
- snprintf(wsi->access_log.header_log, l,
+ lws_snprintf(wsi->access_log.header_log, l,
"%s - - [%s] \"%s %s %s\"",
pa, da, me, uri_ptr,
hver[wsi->u.http.request_version]);
@@ -676,11 +676,11 @@ lws_http_action(struct lws *wsi)
/* > at start indicates deal with by redirect */
if (hit->origin_protocol & 4)
- n = snprintf((char *)end, 256, "%s%s",
+ n = lws_snprintf((char *)end, 256, "%s%s",
oprot[hit->origin_protocol & 1],
hit->origin);
else
- n = snprintf((char *)end, 256,
+ n = lws_snprintf((char *)end, 256,
"https://%s/%s/",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_HOST),
uri_ptr);
diff --git a/libwebsockets-api-doc.html b/libwebsockets-api-doc.html
index ee113712..a7b7197e 100644
--- a/libwebsockets-api-doc.html
+++ b/libwebsockets-api-doc.html
@@ -1923,3 +1923,27 @@ text/html content-encoding, it's replaced with <tt><b>uri_replace_to</b></tt>
<dd>Length of data in <tt><b>buf</b></tt> to send
</dl>
<hr>
+<h2>lws_snprintf - </h2>
+<i>LWS_EXTERN int</i>
+<b>lws_snprintf</b>
+(<i>char *</i> <b>str</b>,
+<i>size_t</i> <b>size</b>,
+<i>const char *</i> <b>format</b>,
+<i></i> <b>...</b>)
+<h3>Arguments</h3>
+<dl>
+<dt><b>...</b>
+<dd>variable arguments
+</dl>
+<h3>Description</h3>
+<blockquote>
+<p>
+\param str: destination buffer
+\param size: bytes left in destination buffer
+\param format: format string
+\param ...: args for format
+<p>
+This lets you correctly truncate buffers by concatenating lengths, if you
+reach the limit the reported length doesn't exceed the limit.
+</blockquote>
+<hr>
diff --git a/lwsws/conf.c b/lwsws/conf.c
index fa00095d..e0059b4d 100644
--- a/lwsws/conf.c
+++ b/lwsws/conf.c
@@ -181,7 +181,7 @@ lejp_globals_cb(struct lejp_ctx *ctx, char reason)
return 0;
}
- a->p += snprintf(a->p, a->end - a->p, "%s", ctx->buf);
+ a->p += lws_snprintf(a->p, a->end - a->p, "%s", ctx->buf);
return 0;
}
@@ -254,7 +254,7 @@ lejp_vhosts_cb(struct lejp_ctx *ctx, char reason)
a->p += n;
a->pvo->value = a->p;
a->pvo->options = NULL;
- a->p += snprintf(a->p, a->end - a->p, "%s", ctx->buf);
+ a->p += lws_snprintf(a->p, a->end - a->p, "%s", ctx->buf);
*(a->p)++ = '\0';
}
@@ -408,7 +408,7 @@ lejp_vhosts_cb(struct lejp_ctx *ctx, char reason)
a->p += n;
mp_cgienv->value = a->p;
mp_cgienv->options = NULL;
- a->p += snprintf(a->p, a->end - a->p, "%s", ctx->buf);
+ a->p += lws_snprintf(a->p, a->end - a->p, "%s", ctx->buf);
*(a->p)++ = '\0';
lwsl_notice(" adding cgi-env '%s' = '%s'\n", mp_cgienv->name,
@@ -452,7 +452,7 @@ lejp_vhosts_cb(struct lejp_ctx *ctx, char reason)
return 0;
}
- a->p += snprintf(a->p, a->end - a->p, "%s", ctx->buf);
+ a->p += lws_snprintf(a->p, a->end - a->p, "%s", ctx->buf);
*(a->p)++ = '\0';
return 0;
@@ -518,7 +518,7 @@ lwsws_get_config_d(void *user, const char *d, const char * const *paths,
}
while (uv_fs_scandir_next(&req, &dent) != UV_EOF) {
- snprintf(path, sizeof(path) - 1, "%s/%s", d, dent.name);
+ lws_snprintf(path, sizeof(path) - 1, "%s/%s", d, dent.name);
ret = lwsws_get_config(user, path, paths, count_paths, cb);
if (ret)
goto bail;
@@ -558,7 +558,7 @@ lwsws_get_config_d(void *user, const char *d, const char * const *paths,
}
for (i = 0; i < n; i++) {
- snprintf(path, sizeof(path) - 1, "%s/%s", d,
+ lws_snprintf(path, sizeof(path) - 1, "%s/%s", d,
namelist[i]->d_name);
ret = lwsws_get_config(user, path, paths, count_paths, cb);
if (ret) {
diff --git a/plugins/protocol_lws_status.c b/plugins/protocol_lws_status.c
index 29e1d65f..c9d828fc 100644
--- a/plugins/protocol_lws_status.c
+++ b/plugins/protocol_lws_status.c
@@ -58,7 +58,7 @@ update_status(struct lws *wsi, struct per_session_data__lws_status *pss)
struct tm tm;
#endif
- p += snprintf(p, 512, " { %s, \"wsi\":\"%d\", \"conns\":[",
+ p += lws_snprintf(p, 512, " { %s, \"wsi\":\"%d\", \"conns\":[",
server_info, live_wsi);
/* render the list */
@@ -79,7 +79,7 @@ update_status(struct lws *wsi, struct per_session_data__lws_status *pss)
if (subsequent)
*p++ = ',';
subsequent = 1;
- p += snprintf(p, sizeof(cache) - (p - start) - 1,
+ p += lws_snprintf(p, sizeof(cache) - (p - start) - 1,
"{\"peer\":\"%s\",\"time\":\"%s\","
"\"ua\":\"%s\"}",
(*pp)->ip, date, (*pp)->user_agent);
diff --git a/test-server/test-fraggle.c b/test-server/test-fraggle.c
index 2137e7b5..80aaea58 100644
--- a/test-server/test-fraggle.c
+++ b/test-server/test-fraggle.c
@@ -349,7 +349,7 @@ int main(int argc, char **argv)
struct lws_client_connect_info i;
address = argv[optind];
- snprintf(ads_port, sizeof(ads_port), "%s:%u",
+ lws_snprintf(ads_port, sizeof(ads_port), "%s:%u",
address, port & 65535);
memset(&i, 0, sizeof(i));
i.context = context;
diff --git a/test-server/test-ping.c b/test-server/test-ping.c
index 3d073d81..65ab942b 100644
--- a/test-server/test-ping.c
+++ b/test-server/test-ping.c
@@ -453,7 +453,7 @@ int main(int argc, char **argv)
/* create client websockets using dumb increment protocol */
address = argv[optind];
- snprintf(ads_port, sizeof(ads_port), "%s:%u",
+ lws_snprintf(ads_port, sizeof(ads_port), "%s:%u",
address, port & 65535);
lwsl_notice("Connecting to %s...\n", ads_port);
memset(&i, 0, sizeof(i));
diff --git a/test-server/test-server-status.c b/test-server/test-server-status.c
index d85897b8..50fe5bf9 100644
--- a/test-server/test-server-status.c
+++ b/test-server/test-server-status.c
@@ -42,7 +42,7 @@ update_status(struct lws *wsi, struct per_session_data__lws_status *pss)
struct tm tm;
#endif
- p += snprintf(p, 512, " { %s, \"wsi\":\"%d\", \"conns\":[",
+ p += lws_snprintf(p, 512, " { %s, \"wsi\":\"%d\", \"conns\":[",
server_info, live_wsi);
/* render the list */
@@ -67,7 +67,7 @@ update_status(struct lws *wsi, struct per_session_data__lws_status *pss)
if (subsequent)
*p++ = ',';
subsequent = 1;
- p += snprintf(p, sizeof(cache) - (p - start) - 1,
+ p += lws_snprintf(p, sizeof(cache) - (p - start) - 1,
"{\"peer\":\"%s\",\"time\":\"%s\","
"\"ua\":\"%s\"}",
(*pp)->ip, date, (*pp)->user_agent);
--
GitLab