replace all calls to sprintf with a format helper that advances a cursor. Also convert the meta-formatter (i.e. results printer) to this scheme

1 files changed, 29 insertions, 11 deletions

diff --git a/ot_http.c b/ot_http.c
index e1798dc..36819c7 100644
--- a/ot_http.c
+++ b/ot_http.c
@@ -24,6 +24,7 @@
 #include "ot_scan.h"
 #include "ot_event.h"
 #include "ot_fdstate.h"
+#include "ot_fmt.h"
 #include "ot_stats.h"
 #include "ot_urlencoded.h"
 #include "trackerlogic.h"
@@ -257,6 +258,7 @@ static ssize_t http_handle_stats(const int64_t sock, struct ot_workstruct *ws, c
                                                 {"txtp", TASK_FULLSCRAPE_TPB_ASCII_PLUS}, {NULL, -3}};
 
   struct http_data *cookie = fdstate_cookie(sock);
+  char             *reply;
   int               mode = TASK_STATS_PEERS, scanon = 1, format = 0;
 
   /* A socket without one is a dead socket, which is what http_sendiovecdata
@@ -333,7 +335,9 @@ static ssize_t http_handle_stats(const int64_t sock, struct ot_workstruct *ws, c
   }
 
   /* Simple stats can be answerred immediately */
-  return ws->reply_size = return_stats_for_tracker(ws->reply, mode, 0);
+  reply = ws->reply;
+  return_stats_for_tracker(&reply, ws->outbuf + G_OUTBUF_SIZE, mode, 0);
+  return ws->reply_size = reply - ws->reply;
 }
 
 #ifdef WANT_MODEST_FULLSCRAPES
@@ -417,9 +421,10 @@ static ssize_t http_handle_fullscrape(const int64_t sock, struct ot_workstruct *
 static ssize_t http_handle_scrape(const int64_t sock, struct ot_workstruct *ws, char *read_ptr) {
   static const ot_keywords keywords_scrape[] = {{"info_hash", 1}, {NULL, -3}};
 
-  ot_hash *multiscrape_buf   = (ot_hash *)ws->request;
-  int      scanon = 1;
-  size_t   numwant = 0;
+  ot_hash *multiscrape_buf = (ot_hash *)ws->request;
+  char    *reply           = ws->reply;
+  int      scanon          = 1;
+  size_t   numwant         = 0;
 
   /* This is to hack around stupid clients that send "scrape ?info_hash" */
   if (read_ptr[-1] != '?') {
@@ -457,7 +462,8 @@ static ssize_t http_handle_scrape(const int64_t sock, struct ot_workstruct *ws,
     numwant = OT_MAXMULTISCRAPE_COUNT;
 
   /* Enough for http header + whole scrape string */
-  ws->reply_size = return_tcp_scrape_for_torrent((const ot_hash *)multiscrape_buf, numwant, ws->reply);
+  return_tcp_scrape_for_torrent((const ot_hash *)multiscrape_buf, numwant, &reply, ws->outbuf + G_OUTBUF_SIZE);
+  ws->reply_size = reply - ws->reply;
   stats_issue_event(EVENT_SCRAPE, FLAG_TCP, ws->reply_size);
   return ws->reply_size;
 }
@@ -493,6 +499,16 @@ static ot_keywords keywords_announce[] = {{"port", 1},    {"left", 2}, {"event",
 #endif
                                           {"peer_id", 9}, {NULL, -3}};
 static ot_keywords keywords_announce_event[] = {{"completed", 1}, {"stopped", 2}, {NULL, -3}};
+
+/* For the replies that are one fixed string and nothing else, where the only
+   thing the caller wants back is how long it turned out */
+static ssize_t     reply_literal(struct ot_workstruct *ws, const char *text) {
+  char *reply = ws->reply;
+
+  fmt_bytes(&reply, ws->outbuf + G_OUTBUF_SIZE, text, strlen(text));
+  return reply - ws->reply;
+}
+
 static ssize_t     http_handle_announce(const int64_t sock, struct ot_workstruct *ws, char *read_ptr) {
   size_t            numwant;
   int64_t           tmp;
@@ -621,7 +637,7 @@ static ssize_t     http_handle_announce(const int64_t sock, struct ot_workstruct
         HTTPERROR_400_PARAM;
       if (*tmp_buf == '-') {
         loglist_reset();
-        return ws->reply_size = sprintf(ws->reply, "Successfully removed.\n");
+        return ws->reply_size = reply_literal(ws, "Successfully removed.\n");
       }
       parsed = ip_parse(tmp_buf, net.address);
       if (!parsed)
@@ -638,7 +654,7 @@ static ssize_t     http_handle_announce(const int64_t sock, struct ot_workstruct
       }
       net.bits = bits;
       loglist_add_network(&net);
-      return ws->reply_size = sprintf(ws->reply, "Successfully added.\n");
+      return ws->reply_size = reply_literal(ws, "Successfully added.\n");
       //}
     } break;
 #endif
@@ -661,7 +677,7 @@ static ssize_t     http_handle_announce(const int64_t sock, struct ot_workstruct
 
   /* Scanned whole query string */
   if (!ws->hash)
-    return ws->reply_size = sprintf(ws->reply, "d14:failure reason80:Your client forgot to send your torrent's info_hash. Please upgrade your client.e");
+    return ws->reply_size = reply_literal(ws, "d14:failure reason80:Your client forgot to send your torrent's info_hash. Please upgrade your client.e");
 
   if (OT_PEERFLAG(&ws->peer) & PEER_FLAG_STOPPED)
     ws->reply_size = remove_peer_from_torrent(FLAG_TCP, ws);
@@ -772,9 +788,11 @@ ssize_t http_handle_request(const int64_t sock, struct ot_workstruct *ws) {
   reply_off       = SUCCESS_HTTP_SIZE_OFF - snprintf(ws->outbuf, 0, "%zd", ws->reply_size);
   ws->reply       = ws->outbuf + reply_off;
 
-  /* 2. Now we sprintf our header so that sprintf writes its terminating '\0' exactly one byte before content starts. Complete
-     packet size is increased by size of header plus one byte '\n', we will copy over '\0' in next step */
-  ws->reply_size += 1 + sprintf(ws->reply, "HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nContent-Length: %zd\r\n\r", ws->reply_size);
+  /* 2. Now we write the header so that its terminating '\0' lands exactly one byte before the content starts. The bound is the
+     space step 1 reserved, so the '\0' falls where step 3 expects it. Complete packet size is increased by size of header plus
+     one byte '\n', we will copy over '\0' in next step */
+  ws->reply_size += 1 + snprintf(ws->reply, (size_t)(SUCCESS_HTTP_HEADER_LENGTH - reply_off),
+                                 "HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nContent-Length: %zd\r\n\r", ws->reply_size);
 
   /* 3. Finally we join both blocks neatly */
   ws->outbuf[SUCCESS_HTTP_HEADER_LENGTH - 1] = '\n';