cmdline: parse numerical options stricter

1 - str2offset() no longer accepts negative numbers since offsets are by
nature positive.

2 - introduced str2unum() for the command line parser that accepts
numericals which are not supposed to be negative, so that it will
properly complain on apparent bad uses and mistakes.

Bug: http://curl.haxx.se/mail/archive-2012-07/0013.html

5 files changed, 78 insertions, 34 deletions

diff --git a/src/tool_getparam.c b/src/tool_getparam.c
index 4205f596a..579437eb7 100644
--- a/src/tool_getparam.c
+++ b/src/tool_getparam.c
@@ -397,8 +397,9 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         GetStr(&config->egd_file, nextarg);
         break;
       case 'c': /* connect-timeout */
-        if(str2num(&config->connecttimeout, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc=str2unum(&config->connecttimeout, nextarg);
+        if(rc)
+          return rc;
         break;
       case 'd': /* ciphers */
         GetStr(&config->cipher_list, nextarg);
@@ -541,8 +542,12 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         break;
 
       case 's': /* --max-redirs */
-        /* specified max no of redirects (http(s)) */
-        if(str2num(&config->maxredirs, nextarg))
+        /* specified max no of redirects (http(s)), this accepts -1 as a
+           special condition */
+        rc = str2num(&config->maxredirs, nextarg);
+        if(rc)
+          return rc;
+        if(config->maxredirs < -1)
           return PARAM_BAD_NUMERIC;
         break;
 
@@ -586,8 +591,9 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
           return PARAM_LIBCURL_DOESNT_SUPPORT;
         break;
       case 'y': /* --max-filesize */
-        if(str2offset(&config->max_filesize, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc = str2offset(&config->max_filesize, nextarg);
+        if(rc)
+          return rc;
         break;
       case 'z': /* --disable-eprt */
         config->disable_eprt = toggle;
@@ -663,16 +669,19 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         config->proxybasic = toggle;
         break;
       case 'g': /* --retry */
-        if(str2num(&config->req_retry, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc = str2unum(&config->req_retry, nextarg);
+        if(rc)
+          return rc;
         break;
       case 'h': /* --retry-delay */
-        if(str2num(&config->retry_delay, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc = str2unum(&config->retry_delay, nextarg);
+        if(rc)
+          return rc;
         break;
       case 'i': /* --retry-max-time */
-        if(str2num(&config->retry_maxtime, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc = str2unum(&config->retry_maxtime, nextarg);
+        if(rc)
+          return rc;
         break;
 
       case 'k': /* --proxy-negotiate */
@@ -759,8 +768,9 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         config->nokeepalive = (!toggle)?TRUE:FALSE;
         break;
       case '3': /* --keepalive-time */
-        if(str2num(&config->alivetime, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc = str2unum(&config->alivetime, nextarg);
+        if(rc)
+          return rc;
         break;
       case '4': /* --post302 */
         config->post302 = toggle;
@@ -786,7 +796,9 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         config->proxyver = CURLPROXY_HTTP_1_0;
         break;
       case '9': /* --tftp-blksize */
-        str2num(&config->tftp_blksize, nextarg);
+        rc = str2unum(&config->tftp_blksize, nextarg);
+        if(rc)
+          return rc;
         break;
       case 'A': /* --mail-from */
         GetStr(&config->mail_from, nextarg);
@@ -911,8 +923,9 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
     case 'C':
       /* This makes us continue an ftp transfer at given position */
       if(!curlx_strequal(nextarg, "-")) {
-        if(str2offset(&config->resume_from, nextarg))
-          return PARAM_BAD_NUMERIC;
+        rc = str2offset(&config->resume_from, nextarg);
+        if(rc)
+          return rc;
         config->resume_from_current = FALSE;
       }
       else {
@@ -1303,8 +1316,9 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
       break;
     case 'm':
       /* specified max time */
-      if(str2num(&config->timeout, nextarg))
-        return PARAM_BAD_NUMERIC;
+      rc = str2unum(&config->timeout, nextarg);
+      if(rc)
+        return rc;
       break;
     case 'M': /* M for manual, huge help */
       if(toggle) { /* --no-manual shows no manual... */
@@ -1618,15 +1632,17 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
       break;
     case 'y':
       /* low speed time */
-      if(str2num(&config->low_speed_time, nextarg))
-        return PARAM_BAD_NUMERIC;
+      rc = str2unum(&config->low_speed_time, nextarg);
+      if(rc)
+        return rc;
       if(!config->low_speed_limit)
         config->low_speed_limit = 1;
       break;
     case 'Y':
       /* low speed limit */
-      if(str2num(&config->low_speed_limit, nextarg))
-        return PARAM_BAD_NUMERIC;
+      rc = str2unum(&config->low_speed_limit, nextarg);
+      if(rc)
+        return rc;
       if(!config->low_speed_time)
         config->low_speed_time = 30;
       break;
diff --git a/src/tool_getparam.h b/src/tool_getparam.h
index 7dc49393b..49cc684c9 100644
--- a/src/tool_getparam.h
+++ b/src/tool_getparam.h
@@ -32,6 +32,7 @@ typedef enum {
   PARAM_HELP_REQUESTED,
   PARAM_GOT_EXTRA_PARAMETER,
   PARAM_BAD_NUMERIC,
+  PARAM_NEGATIVE_NUMERIC,
   PARAM_LIBCURL_DOESNT_SUPPORT,
   PARAM_NO_MEM,
   PARAM_LAST
diff --git a/src/tool_helpers.c b/src/tool_helpers.c
index 87d7c609d..ae8aaaf32 100644
--- a/src/tool_helpers.c
+++ b/src/tool_helpers.c
@@ -54,6 +54,8 @@ const char *param2text(int res)
     return "is badly used here";
   case PARAM_BAD_NUMERIC:
     return "expected a proper numerical parameter";
+  case PARAM_NEGATIVE_NUMERIC:
+    return "expected a positive numerical parameter";
   case PARAM_LIBCURL_DOESNT_SUPPORT:
     return "the installed libcurl version doesn't support this";
   case PARAM_NO_MEM:
diff --git a/src/tool_paramhlp.c b/src/tool_paramhlp.c
index 4d1d17a52..85912a2ef 100644
--- a/src/tool_paramhlp.c
+++ b/src/tool_paramhlp.c
@@ -146,8 +146,8 @@ void cleanarg(char *str)
 }
 
 /*
- * Parse the string and write the integer in the given address. Return
- * non-zero on failure, zero on success.
+ * Parse the string and write the long in the given address. Return non-zero
+ * on failure, zero on success.
  *
  * Since this function gets called with the 'nextarg' pointer from within the
  * getparameter a lot, we must check it for NULL before accessing the str
@@ -161,10 +161,26 @@ int str2num(long *val, const char *str)
     long num = strtol(str, &endptr, 10);
     if((endptr != str) && (endptr == str + strlen(str))) {
       *val = num;
-      return 0;  /* Ok */
+      return PARAM_OK;  /* Ok */
     }
   }
-  return 1; /* badness */
+  return PARAM_BAD_NUMERIC; /* badness */
+}
+
+/*
+ * Parse the string and write the long in the given address. Return non-zero
+ * on failure, zero on success. ONLY ACCEPTS POSITIVE NUMBERS!
+ *
+ * Since this function gets called with the 'nextarg' pointer from within the
+ * getparameter a lot, we must check it for NULL before accessing the str
+ * data.
+ */
+
+int str2unum(long *val, const char *str)
+{
+  if(str[0]=='-')
+    return PARAM_NEGATIVE_NUMERIC; /* badness */
+  return str2num(val, str);
 }
 
 /*
@@ -274,8 +290,8 @@ long proto2num(struct Configurable *config, long *val, const char *str)
 }
 
 /**
- * Parses the given string looking for an offset (which may be
- * a larger-than-integer value).
+ * Parses the given string looking for an offset (which may be a
+ * larger-than-integer value). The offset CANNOT be negative!
  *
  * @param val  the offset to populate
  * @param str  the buffer containing the offset
@@ -283,16 +299,24 @@ long proto2num(struct Configurable *config, long *val, const char *str)
  */
 int str2offset(curl_off_t *val, const char *str)
 {
+  char *endptr;
+  if(str[0] == '-')
+    /* offsets aren't negative, this indicates weird input */
+    return PARAM_NEGATIVE_NUMERIC;
+
 #if(CURL_SIZEOF_CURL_OFF_T > CURL_SIZEOF_LONG)
-  *val = curlx_strtoofft(str, NULL, 0);
+  *val = curlx_strtoofft(str, &endptr, 0);
   if((*val == CURL_OFF_T_MAX || *val == CURL_OFF_T_MIN) && (ERRNO == ERANGE))
-    return 1;
+    return PARAM_BAD_NUMERIC;
 #else
-  *val = strtol(str, NULL, 0);
+  *val = strtol(str, &endptr, 0);
   if((*val == LONG_MIN || *val == LONG_MAX) && ERRNO == ERANGE)
-    return 1;
+    return PARAM_BAD_NUMERIC;
 #endif
-  return 0;
+  if((endptr != str) && (endptr == str + strlen(str)))
+    return 0;  /* Ok */
+
+  return PARAM_BAD_NUMERIC;
 }
 
 ParameterError checkpasswd(const char *kind, /* for what purpose */
diff --git a/src/tool_paramhlp.h b/src/tool_paramhlp.h
index c65450915..50c693efd 100644
--- a/src/tool_paramhlp.h
+++ b/src/tool_paramhlp.h
@@ -32,6 +32,7 @@ ParameterError file2memory(char **bufp, size_t *size, FILE *file);
 void cleanarg(char *str);
 
 int str2num(long *val, const char *str);
+int str2unum(long *val, const char *str); /* for unsigned input numbers */
 
 long proto2num(struct Configurable *config, long *val, const char *str);