shared.c: use execvp() to execute filter commands

This reintroduces the use of execvp(), since the filter commands doesn't
always contain an absolute path (i.e. snapshot compression filters).

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 11 insertions, 57 deletions

diff --git a/shared.c b/shared.c
index 8c3d18a..986f965 100644
--- a/shared.c
+++ b/shared.c
@@ -383,7 +383,7 @@ typedef struct {
         char * value;
 } cgit_env_var;
 
-static char * prepare_env(struct cgit_repo * repo) {
+static void prepare_env(struct cgit_repo * repo) {
         cgit_env_var env_vars[] = {
                 { .name = "CGIT_REPO_URL", .value = repo->url },
                 { .name = "CGIT_REPO_NAME", .value = repo->name },
@@ -394,52 +394,14 @@ static char * prepare_env(struct cgit_repo * repo) {
                 { .name = "CGIT_REPO_CLONE_URL", .value = repo->clone_url }
         };
         int env_var_count = ARRAY_SIZE(env_vars);
-        long values_space = (env_var_count * (PATH_MAX + 64));
-
-        void * buffer;
-        char ** vars;
-        char * values;
-        int vars_index = 0;
-        unsigned int chars_printed;
-
-        /* Allocate buffer for environment variables: first in the buffer is an
-         * array of pointers to argument strings, terminated with a NULL pointer.
-         * After that the argument strings are placed after each other */
-        buffer = malloc(((env_var_count + 1) * sizeof(char *)) + values_space);
-        if (!buffer)
-                return NULL;
-
-        vars = buffer;
-        values = (char *) &vars[env_var_count + 1];
-
-        /* loop over all defined environment variables and their values */
-        while (vars_index < env_var_count) {
-                char * name = env_vars[vars_index].name;
-                char * value = env_vars[vars_index].value;
-
-                if (!value)
-                        value = "";
-
-                chars_printed = snprintf(values, (values_space - 1), "%s=%s", name,
-                                value);
-                if (chars_printed > (values_space - 1)) {
-                        /* Buffer space exhausted: stop adding variables.
-                         * Not all environment variables are defined, but the best we can
-                         * do is to provide the ones that _are_ defined */
-                        break;
-                }
-
-                values[chars_printed] = '\0';
-                *&vars[vars_index] = values;
-                values += (chars_printed + 1);
-                values_space -= (chars_printed + 1);
-                vars_index++;
-        }
-
-        /* terminate the array with pointers */
-        *&vars[vars_index] = NULL;
-
-        return (char *) buffer;
+        cgit_env_var *p, *q;
+        static char *warn = "cgit warning: failed to set env: %s=%s\n";
+
+        p = env_vars;
+        q = p + env_var_count;
+        for (; p < q; p++)
+                if (setenv(p->name, p->value, 1))
+                        fprintf(stderr, warn, p->name, p->value);
 }
 
 int cgit_open_filter(struct cgit_filter *filter, struct cgit_repo * repo)
@@ -450,20 +412,12 @@ int cgit_open_filter(struct cgit_filter *filter, struct cgit_repo * repo)
         chk_zero(pipe(filter->pipe_fh), "Unable to create pipe to subprocess");
         filter->pid = chk_non_negative(fork(), "Unable to create subprocess");
         if (filter->pid == 0) {
-                char * env = NULL;
-
                 close(filter->pipe_fh[1]);
                 chk_non_negative(dup2(filter->pipe_fh[0], STDIN_FILENO),
                         "Unable to use pipe as STDIN");
-
                 if (repo)
-                        env = prepare_env(repo);
-
-                execve(filter->cmd, filter->argv, (char **)env);
-
-                if (env)
-                        free(env);
-
+                        prepare_env(repo);
+                execvp(filter->cmd, filter->argv);
                 die("Unable to exec subprocess %s: %s (%d)", filter->cmd,
                         strerror(errno), errno);
         }