check all snprintf() callers and modify code to work correctly with the return value using tvh_strlcatf2() macro, fixes #2734

src/access.c

@@ -352,10 +352,11 @@ static void
 access_dump_a(access_t *a)
 {
   htsmsg_field_t *f;
+  size_t l = 0;
   char buf[1024];
   int first;
 
-  snprintf(buf, sizeof(buf),
+  tvh_strlcatf2(buf, sizeof(buf), l,
     "%s:%s [%c%c%c%c%c%c%c%c%c], conn=%u, chmin=%llu, chmax=%llu%s",
     a->aa_representative ?: "<no-id>",
     a->aa_username ?: "<no-user>",
@@ -378,14 +379,14 @@ access_dump_a(access_t *a)
       profile_t *pro = profile_find_by_uuid(htsmsg_field_get_str(f) ?: "");
       if (pro) {
         if (first)
-          snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ", profile=");
-        snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%s'%s'",
+          tvh_strlcatf2(buf, sizeof(buf), l, ", profile=");
+        tvh_strlcatf2(buf, sizeof(buf), l, "%s'%s'",
                  first ? "" : ",", pro->pro_name ?: "");
         first = 0;
       }
     }
   } else {
-    snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ", profile=ANY");
+    tvh_strlcatf2(buf, sizeof(buf), l, ", profile=ANY");
   }
 
   if (a->aa_dvrcfgs) {
@@ -394,14 +395,14 @@ access_dump_a(access_t *a)
       dvr_config_t *cfg = dvr_config_find_by_uuid(htsmsg_field_get_str(f) ?: "");
       if (cfg) {
         if (first)
-          snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ", dvr=");
-        snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%s'%s'",
+          tvh_strlcatf2(buf, sizeof(buf), l, ", dvr=");
+        tvh_strlcatf2(buf, sizeof(buf), l, "%s'%s'",
                  first ? "" : ",", cfg->dvr_config_name ?: "");
         first = 0;
       }
     }
   } else {
-    snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ", dvr=ANY");
+    tvh_strlcatf2(buf, sizeof(buf), l, ", dvr=ANY");
   }
 
   if (a->aa_chtags) {
@@ -410,14 +411,14 @@ access_dump_a(access_t *a)
       channel_tag_t *ct = channel_tag_find_by_uuid(htsmsg_field_get_str(f) ?: "");
       if (ct) {
         if (first)
-          snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ", tags=");
-        snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%s'%s'",
+          tvh_strlcatf2(buf, sizeof(buf), l, ", tags=");
+        tvh_strlcatf2(buf, sizeof(buf), l, "%s'%s'",
                  first ? "" : ",", ct->ct_name ?: "");
         first = 0;
       }
     }
   } else {
-    snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ", tag=ANY");
+    tvh_strlcatf2(buf, sizeof(buf), l, ", tag=ANY");
   }
 
   tvhtrace("access", "%s", buf);
@@ -1074,7 +1075,7 @@ access_entry_class_prefix_get(void *o)
       s_addr = htonl(ai->ai_network);
       inet_ntop(AF_INET, &s_addr, addrbuf, sizeof(addrbuf));
     }
-    pos += snprintf(buf+pos, sizeof(buf)-pos, ",%s/%d", addrbuf, ai->ai_prefixlen);
+    tvh_strlcatf2(buf, sizeof(buf), pos, ",%s/%d", addrbuf, ai->ai_prefixlen);
   }
   return &ret;
 }

src/descrambler/capmt.c

@@ -816,6 +816,8 @@ capmt_send_client_info(capmt_t *capmt)
   *(uint32_t *)(buf + 0) = htonl(DVBAPI_CLIENT_INFO);
   *(uint16_t *)(buf + 4) = htons(DVBAPI_PROTOCOL_VERSION); //supported protocol version
   int len = snprintf(buf + 7, sizeof(buf) - 7, "Tvheadend %s", tvheadend_version);
+  if (len >= sizeof(buf) - 7)
+    len = sizeof(buf) - 7 - 1;
   buf[6] = len;
 
   capmt_queue_msg(capmt, 0, 0, (uint8_t *)&buf, len + 7, CAPMT_MSG_FAST);

src/epg.c

@@ -1101,19 +1101,19 @@ size_t epg_episode_number_format
   epg_episode_num_t num;
   epg_episode_get_epnum(episode, &num);
   if ( num.e_num ) {
-    if (pre) i += snprintf(&buf[i], len-i, "%s", pre);
+    if (pre) tvh_strlcatf2(buf, len, i, "%s", pre);
     if ( sfmt && num.s_num ) {
-      i += snprintf(&buf[i], len-i, sfmt, num.s_num);
+      tvh_strlcatf2(buf, len, i, sfmt, num.s_num);
       if ( cfmt && num.s_cnt )
-        i += snprintf(&buf[i], len-i, cfmt, num.s_cnt);
-      if (sep) i += snprintf(&buf[i], len-i, "%s", sep);
+        tvh_strlcatf2(buf, len, i, cfmt, num.s_cnt);
+      if (sep) tvh_strlcatf2(buf, len, i, "%s", sep);
     }
-    i += snprintf(&buf[i], len-i, efmt, num.e_num);
+    tvh_strlcatf2(buf, len, i, efmt, num.e_num);
     if ( cfmt && num.e_cnt )
-      i+= snprintf(&buf[i], len-i, cfmt, num.e_cnt);
+      tvh_strlcatf2(buf, len, i, cfmt, num.e_cnt);
   } else if ( num.text ) {
-    if (pre) i += snprintf(&buf[i], len-i, "%s", pre);
-    i += snprintf(&buf[i], len-i, "%s", num.text);
+    if (pre) tvh_strlcatf2(buf, len, i, "%s", pre);
+    tvh_strlcatf2(buf, len, i, "%s", num.text);
   }
   return i;
 }
@@ -2118,12 +2118,11 @@ size_t epg_genre_get_str ( const epg_genre_t *genre, int major_only,
   if (!_epg_genre_names[maj][0]) return 0;
   min = major_only ? 0 : (genre->code & 0xf);
   if (!min || major_prefix ) {
-    ret = snprintf(buf, len, "%s", _epg_genre_names[maj][0]);
-    if (min) ret += snprintf(buf+ret, len-ret, " : ");
-  }
-  if (min && _epg_genre_names[maj][min]) {
-    ret += snprintf(buf+ret, len-ret, "%s", _epg_genre_names[maj][min]);
+    tvh_strlcatf2(buf, len, ret, "%s", _epg_genre_names[maj][0]);
+    if (min) tvh_strlcatf2(buf, len, ret, " : ");
   }
+  if (min && _epg_genre_names[maj][min])
+    tvh_strlcatf2(buf, len, ret, "%s", _epg_genre_names[maj][min]);
   return ret;
 }
 

src/htsp_server.c

@@ -572,21 +572,18 @@ htsp_build_channel(channel_t *ch, const char *method, htsp_connection_t *htsp)
     if ((strstr(icon, "imagecache") == icon) && htsp->htsp_version < 8) {
       struct sockaddr_storage addr;
       socklen_t addrlen;
-      size_t p = 0;
       char url[256];
       char buf[50];
       addrlen = sizeof(addr);
       getsockname(htsp->htsp_fd, (struct sockaddr*)&addr, &addrlen);
       tcp_get_ip_str((struct sockaddr*)&addr, buf, 50);
-      strcpy(url, "http://");
-      p = strlen(url);
-      p += snprintf(url+p, sizeof(url)-p, "%s%s%s:%d%s",
+      snprintf(url, sizeof(url), "http://%s%s%s:%d%s/%s",
                     (addr.ss_family == AF_INET6)?"[":"",
                     buf,
                     (addr.ss_family == AF_INET6)?"]":"",
                     tvheadend_webui_port,
-                    tvheadend_webroot ?: "");
-      snprintf(url+p, sizeof(url)-p, "/%s", icon);
+                    tvheadend_webroot ?: "",
+                    icon);
       htsmsg_add_str(out, "channelIcon", url);
     } else {
       if (htsp->htsp_version < 15) {

src/http.c

@@ -534,17 +534,17 @@ dump_request(http_connection_t *hc)
 
   first = 1;
   TAILQ_FOREACH(ra, &hc->hc_req_args, link) {
-    ptr += snprintf(buf + ptr, sizeof(buf) - ptr, first ? "?%s=%s" : "&%s=%s", ra->key, ra->val);
+    tvh_strlcatf2(buf, sizeof(buf), ptr, first ? "?%s=%s" : "&%s=%s", ra->key, ra->val);
     first = 0;
   }
 
   first = 1;
   TAILQ_FOREACH(ra, &hc->hc_args, link) {
-    ptr += snprintf(buf + ptr, sizeof(buf) - ptr, first ? "{{%s=%s" : ",%s=%s", ra->key, ra->val);
+    tvh_strlcatf2(buf, sizeof(buf), ptr, first ? "{{%s=%s" : ",%s=%s", ra->key, ra->val);
     first = 0;
   }
   if (!first)
-    ptr += snprintf(buf + ptr, sizeof(buf) - ptr, "}}");
+    tvh_strlcatf2(buf, sizeof(buf), ptr, "}}");
 
   tvhtrace("http", "%s%s", hc->hc_url, buf);
 }

src/input/mpegts/linuxdvb/linuxdvb_satconf.c

@@ -1426,7 +1426,7 @@ linuxdvb_diseqc_send
   for (i = 0; i < len; i++) {
     message.msg[3 + i] = (uint8_t)va_arg(ap, int);
 #if ENABLE_TRACE
-    c += snprintf(buf + c, sizeof(buf) - c, "%02X ", message.msg[3 + i]);
+    tvh_strlcatf2(buf, sizeof(buf), c, "%02X ", message.msg[3 + i]);
 #endif
   }
   va_end(ap);

src/input/mpegts/mpegts_pid.c

@@ -200,7 +200,6 @@ mpegts_pid_dump(mpegts_apids_t *pids, char *buf, int len)
   if (pids->all)
     return snprintf(buf, len, "all");
   for (i = 0; i < pids->count && l + 1 < len; i++)
-    l += snprintf(buf + l, len - l, "%s%i",
-                  i > 0 ? "," : "", pids->pids[i]);
+    tvh_strlcatf2(buf, len, l, "%s%i", i > 0 ? "," : "", pids->pids[i]);
   return l;
 }

src/satip/rtp.c

@@ -516,7 +516,7 @@ satip_status_build(satip_rtp_session_t *rtp, char *buf, int len)
     return 0;
   }
 
-  return r;
+  return r >= len ? len - 1 : r;
 }
 
 /*

src/satip/rtsp.c

@@ -1039,11 +1039,9 @@ play:
 
   dvb_mux_conf_str(dmc, buf, sizeof(buf));
   r = strlen(buf);
-  if (r + 1 < sizeof(buf))
-    r += snprintf(buf + r, sizeof(buf) - r, " pids ");
-  if (r + 1 < sizeof(buf) &&
-      mpegts_pid_dump(&rs->pids, buf + r, sizeof(buf) - r) == 0)
-    snprintf(buf + r, sizeof(buf) - r, "<none>");
+  tvh_strlcatf2(buf, sizeof(buf), r, " pids ");
+  if (mpegts_pid_dump(&rs->pids, buf + r, sizeof(buf) - r) == 0)
+    tvh_strlcatf2(buf, sizeof(buf), r, "<none>");
 
   tvhdebug("satips", "%i/%s/%d: %s from %s:%d %s",
            rs->frontend, rs->session, rs->stream,

src/subscriptions.c

@@ -180,10 +180,10 @@ subscription_show_info(th_subscription_t *s)
   char buf[512];
   channel_t *ch = s->ths_channel;
   source_info_t si;
-  size_t buflen;
+  size_t l = 0;
 
   s->ths_service->s_setsourceinfo(s->ths_service, &si);
-  buflen = snprintf(buf, sizeof(buf),
+  tvh_strlcatf2(buf, sizeof(buf), l,
 	   "\"%s\" subscribing on \"%s\", weight: %d, adapter: \"%s\", "
 	   "network: \"%s\", mux: \"%s\", provider: \"%s\", service: \"%s\"",
 	   s->ths_title, ch ? channel_get_name(ch) : "none", s->ths_weight,
@@ -195,17 +195,16 @@ subscription_show_info(th_subscription_t *s)
   service_source_info_free(&si);
 
   if (s->ths_prch && s->ths_prch->prch_pro)
-    buflen += snprintf(buf + buflen, sizeof(buf) - buflen,
+    tvh_strlcatf2(buf, sizeof(buf), l,
                        ", profile=\"%s\"",
                        s->ths_prch->prch_pro->pro_name ?: "");
 
-  if (s->ths_hostname) {
-    snprintf(buf + buflen, sizeof(buf) - buflen,
+  if (s->ths_hostname)
+    tvh_strlcatf2(buf, sizeof(buf), l,
              ", hostname=\"%s\", username=\"%s\", client=\"%s\"",
              s->ths_hostname ?: "<N/A>",
              s->ths_username ?: "<N/A>",
              s->ths_client   ?: "<N/A>");
-  }
 
   tvhlog(LOG_INFO, "subscription", "%04X: %s", shortid(s), buf);
 }
@@ -502,7 +501,7 @@ subscription_unsubscribe(th_subscription_t *s, int quiet)
 {
   service_t *t = s->ths_service;
   char buf[512];
-  size_t buflen;
+  size_t l = 0;
 
   lock_assert(&global_lock);
 
@@ -520,20 +519,18 @@ subscription_unsubscribe(th_subscription_t *s, int quiet)
 
   if (s->ths_channel != NULL) {
     LIST_REMOVE(s, ths_channel_link);
-    snprintf(buf, sizeof(buf), "\"%s\" unsubscribing from \"%s\"",
+    tvh_strlcatf2(buf, sizeof(buf), l, "\"%s\" unsubscribing from \"%s\"",
              s->ths_title, channel_get_name(s->ths_channel));
   } else {
-    snprintf(buf, sizeof(buf), "\"%s\" unsubscribing", s->ths_title);
+    tvh_strlcatf2(buf, sizeof(buf), l, "\"%s\" unsubscribing", s->ths_title);
   }
 
-  if (s->ths_hostname) {
-    buflen = strlen(buf);
-    snprintf(buf + buflen, sizeof(buf) - buflen,
+  if (s->ths_hostname)
+    tvh_strlcatf2(buf, sizeof(buf), l,
              ", hostname=\"%s\", username=\"%s\", client=\"%s\"",
              s->ths_hostname ?: "<N/A>",
              s->ths_username ?: "<N/A>",
              s->ths_client   ?: "<N/A>");
-  }
   tvhlog(quiet ? LOG_TRACE : LOG_INFO, "subscription", "%04X: %s", shortid(s), buf);
 
   if (t) {

src/tvheadend.h

@@ -575,12 +575,19 @@ extern void scopedunlock(pthread_mutex_t **mtxp);
 
 #define scopedgloballock() scopedlock(&global_lock)
 
-#define tvh_strdupa(n) ({ int tvh_l = strlen(n); \
- char *tvh_b = alloca(tvh_l + 1); \
- memcpy(tvh_b, n, tvh_l + 1); })
+#define tvh_strdupa(n) \
+  ({ int tvh_l = strlen(n); \
+     char *tvh_b = alloca(tvh_l + 1); \
+     memcpy(tvh_b, n, tvh_l + 1); })
 
 #define tvh_strlcatf(buf, size, fmt...) \
- snprintf((buf) + strlen(buf), (size) - strlen(buf), fmt)
+  ({ size_t __l = strlen(buf); \
+     int __r = snprintf((buf) + __l, (size) - __l, fmt); \
+     __r >= (size) - __l ? (size) - 1 : __l + __r }}
+
+#define tvh_strlcatf2(buf, size, ptr, fmt...) \
+  do { int __r = snprintf((buf) + ptr, (size) - ptr, fmt); \
+       ptr = __r >= (size) - ptr ? (size) - 1 : ptr + __r; } while (0)
 
 static inline const char *tvh_strbegins(const char *s1, const char *s2)
 {

src/tvhlog.c

@@ -74,7 +74,7 @@ tvhlog_get_subsys ( htsmsg_t *ss, char *subsys, size_t len )
   if (ss) {
     HTSMSG_FOREACH(f, ss) {
       if (f->hmf_type != HMF_S64) continue;
-      c += snprintf(subsys+c, len-c, "%s%c%s",
+      tvh_strlcatf2(subsys, len, c, "%s%c%s",
                     first ? "" : ",",
                     f->hmf_s64 ? '+' : '-',
                     f->hmf_name);
@@ -168,7 +168,7 @@ tvhlog_process
   l = strftime(t, sizeof(t), "%F %T", &tm);// %d %H:%M:%S", &tm);
   if (options & TVHLOG_OPT_MILLIS) {
     int ms = msg->time.tv_usec / 1000;
-    snprintf(t+l, sizeof(t)-l, ".%03d", ms);
+    tvh_strlcatf2(t, sizeof(t), l, ".%03d", ms);
   }
 
   /* Comet (debug must still be enabled??) */
@@ -311,15 +311,15 @@ void tvhlogv ( const char *file, int line,
   /* Basic message */
   l = 0;
   if (options & TVHLOG_OPT_THREAD) {
-    l += snprintf(buf + l, sizeof(buf) - l, "tid %ld: ", (long)pthread_self());
+    tvh_strlcatf2(buf, sizeof(buf), l, "tid %ld: ", (long)pthread_self());
   }
-  l += snprintf(buf + l, sizeof(buf) - l, "%s: ", subsys);
+  tvh_strlcatf2(buf, sizeof(buf), l, "%s: ", subsys);
   if (options & TVHLOG_OPT_FILELINE && severity >= LOG_DEBUG)
-    l += snprintf(buf + l, sizeof(buf) - l, "(%s:%d) ", file, line);
+    tvh_strlcatf2(buf, sizeof(buf), l, "(%s:%d) ", file, line);
   if (args)
-    l += vsnprintf(buf + l, sizeof(buf) - l, fmt, *args);
+    vsnprintf(buf + l, sizeof(buf) - l, fmt, *args);
   else
-    l += snprintf(buf + l, sizeof(buf) - l, "%s", fmt);
+    snprintf(buf + l, sizeof(buf) - l, "%s", fmt);
 
   /* Store */
   tvhlog_msg_t *msg = calloc(1, sizeof(tvhlog_msg_t));
@@ -381,9 +381,9 @@ _tvhlog_hexdump(const char *file, int line,
     c = 0;
     for (i = 0; i < HEXDUMP_WIDTH; i++) {
       if (i >= len)
-        c += snprintf(str+c, sizeof(str)-c, "   ");
+        tvh_strlcatf2(str, sizeof(str), c, "   ");
       else
-        c += snprintf(str+c, sizeof(str)-c, "%02X ", data[i]);
+        tvh_strlcatf2(str, sizeof(str), c, "%02X ", data[i]);
     }
     for (i = 0; i < HEXDUMP_WIDTH; i++) {
       if (i < len) {