Cleanup option keyword/environment substitution

[fio.git] / options.c

diff --git a/options.c b/options.c
index bb46dc9df8cbf707a87671c4b1f0b1867dd79f4b..84bf5ac345ccdda9d1ccf7f66d7a90beb57b0c94 100644 (file)
--- a/options.c
+++ b/options.c
@@ -2218,15 +2218,15 @@ void fio_keywords_init(void)
 
 static char *bc_calc(char *str)
 {
-       char *buf, *tmp, opt[80];
+       char buf[128], *tmp;
        FILE *f;
        int ret;
 
        /*
         * No math, just return string
         */
-       if (!strchr(str, '+') && !strchr(str, '-') && !strchr(str, '*') &&
-           !strchr(str, '/'))
+       if ((!strchr(str, '+') && !strchr(str, '-') && !strchr(str, '*') &&
+            !strchr(str, '/')) || strchr(str, '\''))
                return str;
 
        /*
@@ -2237,37 +2237,89 @@ static char *bc_calc(char *str)
                return str;
 
        tmp++;
-       memset(opt, 0, sizeof(opt));
-       strncpy(opt, str, tmp - str);
 
-       buf = malloc(128);
+       /*
+        * Prevent buffer overflows; such a case isn't reasonable anyway
+        */
+       if (strlen(str) >= 128 || strlen(tmp) > 100)
+               return str;
 
        sprintf(buf, "which %s > /dev/null", BC_APP);
        if (system(buf)) {
                log_err("fio: bc is needed for performing math\n");
-               free(buf);
                return NULL;
        }
 
-       sprintf(buf, "echo %s | %s", tmp, BC_APP);
+       sprintf(buf, "echo '%s' | %s", tmp, BC_APP);
        f = popen(buf, "r");
        if (!f) {
-               free(buf);
                return NULL;
        }
 
-       ret = fread(buf, 1, 128, f);
+       ret = fread(&buf[tmp - str], 1, 128 - (tmp - str), f);
        if (ret <= 0) {
-               free(buf);
                return NULL;
        }
 
-       buf[ret - 1] = '\0';
-       strcat(opt, buf);
-       strcpy(buf, opt);
        pclose(f);
+       buf[(tmp - str) + ret - 1] = '\0';
+       memcpy(buf, str, tmp - str);
        free(str);
-       return buf;
+       return strdup(buf);
+}
+
+/*
+ * Return a copy of the input string with substrings of the form ${VARNAME}
+ * substituted with the value of the environment variable VARNAME.  The
+ * substitution always occurs, even if VARNAME is empty or the corresponding
+ * environment variable undefined.
+ */
+static char *option_dup_subs(const char *opt)
+{
+       char out[OPT_LEN_MAX+1];
+       char in[OPT_LEN_MAX+1];
+       char *outptr = out;
+       char *inptr = in;
+       char *ch1, *ch2, *env;
+       ssize_t nchr = OPT_LEN_MAX;
+       size_t envlen;
+
+       if (strlen(opt) + 1 > OPT_LEN_MAX) {
+               log_err("OPT_LEN_MAX (%d) is too small\n", OPT_LEN_MAX);
+               return NULL;
+       }
+
+       in[OPT_LEN_MAX] = '\0';
+       strncpy(in, opt, OPT_LEN_MAX);
+
+       while (*inptr && nchr > 0) {
+               if (inptr[0] == '$' && inptr[1] == '{') {
+                       ch2 = strchr(inptr, '}');
+                       if (ch2 && inptr+1 < ch2) {
+                               ch1 = inptr+2;
+                               inptr = ch2+1;
+                               *ch2 = '\0';
+
+                               env = getenv(ch1);
+                               if (env) {
+                                       envlen = strlen(env);
+                                       if (envlen <= nchr) {
+                                               memcpy(outptr, env, envlen);
+                                               outptr += envlen;
+                                               nchr -= envlen;
+                                       }
+                               }
+
+                               continue;
+                       }
+               }
+
+               *outptr++ = *inptr++;
+               --nchr;
+       }
+
+       *outptr = '\0';
+       return strdup(out);
 }
 
 /*
@@ -2277,6 +2329,7 @@ static char *fio_keyword_replace(char *opt)
 {
        char *s;
        int i;
+       int docalc = 0;
 
        for (i = 0; fio_keywords[i].word != NULL; i++) {
                struct fio_keyword *kw = &fio_keywords[i];
@@ -2306,29 +2359,51 @@ static char *fio_keyword_replace(char *opt)
                         * replace opt and free the old opt
                         */
                        opt = new;
-                       //free(o_org);
+                       free(o_org);
 
-                       /*
-                        * Check for potential math and invoke bc, if possible
-                        */
-                       opt = bc_calc(opt);
+                       docalc = 1;
                }
        }
 
+       /*
+        * Check for potential math and invoke bc, if possible
+        */
+       if (docalc)
+               opt = bc_calc(opt);
+
        return opt;
 }
 
+static char **dup_and_sub_options(char **opts, int num_opts)
+{
+       int i;
+       char **opts_copy = malloc(num_opts * sizeof(*opts));
+       for (i = 0; i < num_opts; i++) {
+               opts_copy[i] = option_dup_subs(opts[i]);
+               if (!opts_copy[i])
+                       continue;
+               opts_copy[i] = fio_keyword_replace(opts_copy[i]);
+       }
+       return opts_copy;
+}
+
 int fio_options_parse(struct thread_data *td, char **opts, int num_opts)
 {
        int i, ret;
+       char **opts_copy;
 
        sort_options(opts, options, num_opts);
+       opts_copy = dup_and_sub_options(opts, num_opts);
 
        for (ret = 0, i = 0; i < num_opts; i++) {
-               opts[i] = fio_keyword_replace(opts[i]);
-               ret |= parse_option(opts[i], options, td);
+               ret |= parse_option(opts_copy[i], opts[i], options, td);
+
+               if (opts_copy[i])
+                       free(opts_copy[i]);
+               opts_copy[i] = NULL;
        }
 
+       free(opts_copy);
        return ret;
 }