Initial version.

1 files changed, 253 insertions, 0 deletions

diff --git a/src/nxt_process_title.c b/src/nxt_process_title.c
new file mode 100644
index 00000000..76533a6e
--- /dev/null
+++ b/src/nxt_process_title.c
@@ -0,0 +1,253 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#include <nxt_main.h>
+
+
+/* The arguments passed to main(). */
+char  **nxt_process_argv;
+
+/*
+ * MacOSX environ(7):
+ *
+ *   Shared libraries and bundles don't have direct access to environ,
+ *   which is only available to the loader ld(1) when a complete program
+ *   is being linked.
+ *
+ * So nxt_process_environ contains an address of environ to allow
+ * change environ[] placement.
+ */
+char  ***nxt_process_environ;
+
+
+#if (NXT_SETPROCTITLE_ARGV)
+
+/*
+ * A process title on Linux, Solaris, and MacOSX can be changed by
+ * copying a new title to a place where the program argument argv[0]
+ * points originally to.  However, the argv[0] may be too small to hold
+ * the new title.  Fortunately, these OSes place the program argument
+ * argv[] strings and the environment environ[] strings contiguously
+ * and their space can be used for the long new process title.
+ *
+ * Solaris "ps" command shows the new title only if it is run in
+ * UCB mode: either "/usr/ucb/ps -axwww" or "/usr/bin/ps axwww".
+ */
+
+
+static u_char  *nxt_process_title_start;
+static u_char  *nxt_process_title_end;
+
+
+void
+nxt_process_arguments(char **orig_argv, char ***orig_envp)
+{
+    u_char      *p, *end, *argv_end, **argv, **env;
+    size_t      size, argv_size, environ_size, strings_size;
+    nxt_uint_t  i;
+
+    nxt_process_argv = orig_argv;
+    nxt_process_environ = orig_envp;
+
+    if (orig_envp == NULL) {
+        return;
+    }
+
+    /*
+     * Set a conservative title space for a case if program argument
+     * strings and environment strings are not contiguous.
+     */
+    argv = (u_char **) orig_argv;
+    nxt_process_title_start = argv[0];
+    nxt_process_title_end = argv[0] + nxt_strlen(argv[0]);
+
+    end = argv[0];
+    strings_size = 0;
+    argv_size = sizeof(void *);
+
+    for (i = 0; argv[i] != NULL; i++) {
+        argv_size += sizeof(void *);
+
+        if (argv[i] == end) {
+            /* Argument strings are contiguous. */
+            size = nxt_strlen(argv[i]) + 1;
+            strings_size += size;
+            end = argv[i] + size;
+        }
+    }
+
+    argv = nxt_malloc(argv_size);
+    if (argv == NULL) {
+        return;
+    }
+
+    /*
+     * Copy the entire original argv[] array.  The elements of this array
+     * can point to copied strings or if original argument strings are not
+     * contiguous, to the original argument strings.
+     */
+    nxt_memcpy(argv, orig_argv, argv_size);
+
+    /*
+     * The argv[1] must be set to NULL on Solaris otherwise the "ps"
+     * command outputs strings pointed by original argv[] elements.
+     * The original argv[] array has always at least two elements so
+     * it is safe to set argv[1].
+     */
+    orig_argv[1] = NULL;
+
+    nxt_process_argv = (char **) argv;
+
+    argv_end = end;
+    env = (u_char **) *orig_envp;
+    environ_size = sizeof(void *);
+
+    for (i = 0; env[i] != NULL; i++) {
+        environ_size += sizeof(void *);
+
+        if (env[i] == end) {
+            /* Environment strings are contiguous. */
+            size = nxt_strlen(env[i]) + 1;
+            strings_size += size;
+            end = env[i] + size;
+        }
+    }
+
+    p = nxt_malloc(strings_size);
+    if (p == NULL) {
+        return;
+    }
+
+    if (argv_end == end) {
+        /*
+         * There is no reason to modify environ if arguments
+         * and environment are not contiguous.
+         */
+        nxt_thread_log_debug("arguments and environment are not contiguous");
+        goto done;
+    }
+
+    end = argv[0];
+
+    for (i = 0; argv[i] != NULL; i++) {
+
+        if (argv[i] != end) {
+            /* Argument strings are not contiguous. */
+            goto done;
+        }
+
+        size = nxt_strlen(argv[i]) + 1;
+        nxt_memcpy(p, argv[i], size);
+
+        end = argv[i] + size;
+        argv[i] = p;
+        p += size;
+    }
+
+    env = nxt_malloc(environ_size);
+    if (env == NULL) {
+        return;
+    }
+
+    /*
+     * Copy the entire original environ[] array.  The elements of
+     * this array can point to copied strings or if original environ
+     * strings are not contiguous, to the original environ strings.
+     */
+    nxt_memcpy(env, *orig_envp, environ_size);
+
+    /* Set the global environ variable to the new array. */
+    *orig_envp = (char **) env;
+
+    for (i = 0; env[i] != NULL; i++) {
+
+        if (env[i] != end) {
+            /* Environment strings are not contiguous. */
+            goto done;
+        }
+
+        size = nxt_strlen(env[i]) + 1;
+        nxt_memcpy(p, env[i], size);
+
+        end = env[i] + size;
+        env[i] = p;
+        p += size;
+    }
+
+done:
+
+    /* Preserve space for the trailing zero. */
+    end--;
+
+    nxt_process_title_end = end;
+}
+
+
+void
+nxt_process_title(const char *title)
+{
+    u_char  *p, *start, *end;
+
+    start = nxt_process_title_start;
+
+    if (start == NULL) {
+        return;
+    }
+
+    end = nxt_process_title_end;
+
+    p = nxt_sprintf(start, end, "%s", title);
+
+#if (NXT_SOLARIS)
+    /*
+     * Solaris "ps" command shows a new process title only if it is
+     * longer than original command line.  A simple workaround is just
+     * to append the original command line in parenthesis to the title.
+     */
+    {
+        size_t      size;
+        nxt_uint_t  i;
+
+        size = 0;
+
+        for (i = 0; nxt_process_argv[i] != NULL; i++) {
+            size += nxt_strlen(nxt_process_argv[i]);
+        }
+
+        if (size > (size_t) (p - start)) {
+
+            p = nxt_sprintf(p, end, " (");
+
+            for (i = 0; nxt_process_argv[i] != NULL; i++) {
+                p = nxt_sprintf(p, end, "%s ", nxt_process_argv[i]);
+            }
+
+            if (*(p - 1) == ' ') {
+                *(p - 1) = ')';
+            }
+        }
+    }
+#endif
+
+    /*
+     * A process title must be padded with zeros on MacOSX.  Otherwise
+     * the "ps" command may output parts of environment strings.
+     */
+    nxt_memset(p, '\0', end - p);
+
+    nxt_thread_log_debug("setproctitle: \"%s\"", start);
+}
+
+#else /* !(NXT_SETPROCTITLE_ARGV) */
+
+void
+nxt_process_arguments(char **orig_argv, char ***orig_envp)
+{
+    nxt_process_argv = orig_argv;
+    nxt_process_environ = orig_envp;
+}
+
+#endif