mime: some more strlen() call removals.

Closes #8423

2 files changed, 33 insertions, 30 deletions

diff --git a/lib/mime.c b/lib/mime.c
index 3cf420b84..aba9e7683 100644
--- a/lib/mime.c
+++ b/lib/mime.c
@@ -314,7 +314,7 @@ static char *escape_string(struct Curl_easy *data,
 
   Curl_dyn_init(&db, CURL_MAX_INPUT_LENGTH);
 
-  for(result = Curl_dyn_add(&db, ""); !result && *src; src++) {
+  for(result = Curl_dyn_addn(&db, STRCONST("")); !result && *src; src++) {
     for(p = table; *p && **p != *src; p++)
       ;
 
@@ -339,9 +339,9 @@ static char *match_header(struct curl_slist *hdr, const char *lbl, size_t len)
 }
 
 /* Get a header from an slist. */
-static char *search_header(struct curl_slist *hdrlist, const char *hdr)
+static char *search_header(struct curl_slist *hdrlist,
+                           const char *hdr, size_t len)
 {
-  size_t len = strlen(hdr);
   char *value = NULL;
 
   for(; !value && hdrlist; hdrlist = hdrlist->next)
@@ -758,7 +758,7 @@ static void mime_file_free(void *ptr)
 static size_t readback_bytes(struct mime_state *state,
                              char *buffer, size_t bufsize,
                              const char *bytes, size_t numbytes,
-                             const char *trail)
+                             const char *trail, size_t traillen)
 {
   size_t sz;
   size_t offset = curlx_sotouz(state->offset);
@@ -768,13 +768,11 @@ static size_t readback_bytes(struct mime_state *state,
     bytes += offset;
   }
   else {
-    size_t tsz = strlen(trail);
-
     sz = offset - numbytes;
-    if(sz >= tsz)
+    if(sz >= traillen)
       return 0;
     bytes = trail + sz;
-    sz = tsz - sz;
+    sz = traillen - sz;
   }
 
   if(sz > bufsize)
@@ -943,13 +941,14 @@ static size_t readback_part(curl_mimepart *part,
         mimesetstate(&part->state, MIMESTATE_USERHEADERS, part->userheaders);
       else {
         sz = readback_bytes(&part->state, buffer, bufsize,
-                            hdr->data, strlen(hdr->data), "\r\n");
+                            hdr->data, strlen(hdr->data), STRCONST("\r\n"));
         if(!sz)
           mimesetstate(&part->state, part->state.state, hdr->next);
       }
       break;
     case MIMESTATE_EOH:
-      sz = readback_bytes(&part->state, buffer, bufsize, "\r\n", 2, "");
+      sz = readback_bytes(&part->state, buffer, bufsize, STRCONST("\r\n"),
+                          STRCONST(""));
       if(!sz)
         mimesetstate(&part->state, MIMESTATE_BODY, NULL);
       break;
@@ -1014,13 +1013,18 @@ static size_t mime_subparts_read(char *buffer, size_t size, size_t nitems,
       mime->state.offset += 2;
       break;
     case MIMESTATE_BOUNDARY1:
-      sz = readback_bytes(&mime->state, buffer, nitems, "\r\n--", 4, "");
+      sz = readback_bytes(&mime->state, buffer, nitems, STRCONST("\r\n--"),
+                          STRCONST(""));
       if(!sz)
         mimesetstate(&mime->state, MIMESTATE_BOUNDARY2, part);
       break;
     case MIMESTATE_BOUNDARY2:
-      sz = readback_bytes(&mime->state, buffer, nitems, mime->boundary,
-                          strlen(mime->boundary), part? "\r\n": "--\r\n");
+      if(part)
+        sz = readback_bytes(&mime->state, buffer, nitems, mime->boundary,
+                            MIME_BOUNDARY_LEN, STRCONST("\r\n"));
+      else
+        sz = readback_bytes(&mime->state, buffer, nitems, mime->boundary,
+                            MIME_BOUNDARY_LEN, STRCONST("--\r\n"));
       if(!sz) {
         mimesetstate(&mime->state, MIMESTATE_CONTENT, part);
       }
@@ -1614,10 +1618,9 @@ CURLcode Curl_mime_rewind(curl_mimepart *part)
 
 /* Compute header list size. */
 static size_t slist_size(struct curl_slist *s,
-                         size_t overhead, const char *skip)
+                         size_t overhead, const char *skip, size_t skiplen)
 {
   size_t size = 0;
-  size_t skiplen = skip? strlen(skip): 0;
 
   for(; s; s = s->next)
     if(!skip || !match_header(s, skip, skiplen))
@@ -1635,7 +1638,7 @@ static curl_off_t multipart_size(curl_mime *mime)
   if(!mime)
     return 0;           /* Not present -> empty. */
 
-  boundarysize = 4 + strlen(mime->boundary) + 2;
+  boundarysize = 4 + MIME_BOUNDARY_LEN + 2;
   size = boundarysize;  /* Final boundary - CRLF after headers. */
 
   for(part = mime->firstpart; part; part = part->nextpart) {
@@ -1666,8 +1669,8 @@ curl_off_t Curl_mime_size(curl_mimepart *part)
 
   if(size >= 0 && !(part->flags & MIME_BODY_ONLY)) {
     /* Compute total part size. */
-    size += slist_size(part->curlheaders, 2, NULL);
-    size += slist_size(part->userheaders, 2, "Content-Type");
+    size += slist_size(part->curlheaders, 2, NULL, 0);
+    size += slist_size(part->userheaders, 2, STRCONST("Content-Type"));
     size += 2;    /* CRLF after headers. */
   }
   return size;
@@ -1743,10 +1746,9 @@ const char *Curl_mime_contenttype(const char *filename)
   return NULL;
 }
 
-static bool content_type_match(const char *contenttype, const char *target)
+static bool content_type_match(const char *contenttype,
+                               const char *target, size_t len)
 {
-  size_t len = strlen(target);
-
   if(contenttype && strncasecompare(contenttype, target, len))
     switch(contenttype[len]) {
     case '\0':
@@ -1782,7 +1784,7 @@ CURLcode Curl_mime_prepare_headers(curl_mimepart *part,
   /* Check if content type is specified. */
   customct = part->mimetype;
   if(!customct)
-    customct = search_header(part->userheaders, "Content-Type");
+    customct = search_header(part->userheaders, STRCONST("Content-Type"));
   if(customct)
     contenttype = customct;
 
@@ -1811,12 +1813,12 @@ CURLcode Curl_mime_prepare_headers(curl_mimepart *part,
       boundary = mime->boundary;
   }
   else if(contenttype && !customct &&
-          content_type_match(contenttype, "text/plain"))
+          content_type_match(contenttype, STRCONST("text/plain")))
     if(strategy == MIMESTRATEGY_MAIL || !part->filename)
       contenttype = NULL;
 
   /* Issue content-disposition header only if not already set by caller. */
-  if(!search_header(part->userheaders, "Content-Disposition")) {
+  if(!search_header(part->userheaders, STRCONST("Content-Disposition"))) {
     if(!disposition)
       if(part->filename || part->name ||
         (contenttype && !strncasecompare(contenttype, "multipart/", 10)))
@@ -1863,7 +1865,8 @@ CURLcode Curl_mime_prepare_headers(curl_mimepart *part,
   }
 
   /* Content-Transfer-Encoding header. */
-  if(!search_header(part->userheaders, "Content-Transfer-Encoding")) {
+  if(!search_header(part->userheaders,
+                    STRCONST("Content-Transfer-Encoding"))) {
     if(part->encoder)
       cte = part->encoder->name;
     else if(contenttype && strategy == MIMESTRATEGY_MAIL &&
@@ -1887,7 +1890,7 @@ CURLcode Curl_mime_prepare_headers(curl_mimepart *part,
     curl_mimepart *subpart;
 
     disposition = NULL;
-    if(content_type_match(contenttype, "multipart/form-data"))
+    if(content_type_match(contenttype, STRCONST("multipart/form-data")))
       disposition = "form-data";
     for(subpart = mime->firstpart; subpart; subpart = subpart->nextpart) {
       ret = Curl_mime_prepare_headers(subpart, NULL, disposition, strategy);
diff --git a/lib/mime.h b/lib/mime.h
index 56642ae66..9e6278564 100644
--- a/lib/mime.h
+++ b/lib/mime.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -91,8 +91,8 @@ struct mime_state {
   curl_off_t offset;          /* State-dependent offset. */
 };
 
-/* minimum buffer size for the boundary string */
-#define MIME_BOUNDARY_LEN (24 + MIME_RAND_BOUNDARY_CHARS + 1)
+/* Boundary string length. */
+#define MIME_BOUNDARY_LEN (24 + MIME_RAND_BOUNDARY_CHARS)
 
 /* A mime multipart. */
 struct curl_mime {
@@ -100,7 +100,7 @@ struct curl_mime {
   curl_mimepart *parent;           /* Parent part. */
   curl_mimepart *firstpart;        /* First part. */
   curl_mimepart *lastpart;         /* Last part. */
-  char boundary[MIME_BOUNDARY_LEN]; /* The part boundary. */
+  char boundary[MIME_BOUNDARY_LEN + 1]; /* The part boundary. */
   struct mime_state state;         /* Current readback state. */
 };