diff options
| -rw-r--r-- | ChangeLog.txt | 4 | ||||
| -rw-r--r-- | pseudo.c | 1 | ||||
| -rw-r--r-- | pseudo_util.c | 130 |
3 files changed, 104 insertions, 31 deletions
diff --git a/ChangeLog.txt b/ChangeLog.txt index 4f17c02..c912c6a 100644 --- a/ChangeLog.txt +++ b/ChangeLog.txt @@ -1,3 +1,7 @@ +2010-06-29: + * (seebs) handle the other half of the suffix case -- when + libpseudo is in LD_PRELOAD under another name. + 2010-06-28: 0.3 * (seebs) back out PSEUDO_SUFFIX -- it causes problem when rebuilding the library but not the server, but this is @@ -88,6 +88,7 @@ main(int argc, char *argv[]) { pseudo_debug(2, "can't run daemon with libpseudo in LD_PRELOAD\n"); if (getenv("PSEUDO_RELOADED")) { pseudo_diag("I can't seem to make LD_PRELOAD go away. Sorry.\n"); + pseudo_diag("LD_PRELOAD: %s\n", ld_env); exit(EXIT_FAILURE); } setenv("PSEUDO_RELOADED", "YES", 1); diff --git a/pseudo_util.c b/pseudo_util.c index f524f9f..5379c11 100644 --- a/pseudo_util.c +++ b/pseudo_util.c @@ -24,6 +24,7 @@ #include <string.h> #include <stdlib.h> #include <sys/stat.h> +#include <regex.h> #include <time.h> #include <unistd.h> #include <limits.h> @@ -49,7 +50,84 @@ static int pseudo_append_elements(char **newpath, char **root, size_t *allocated extern char **environ; static ssize_t pseudo_max_pathlen = -1; static ssize_t pseudo_sys_max_pathlen = -1; + +/* in our installed system, we usually use a name of the form + * libpseudoCHECKSUM.so, where CHECKSUM is an md5 checksum of the host + * libc.so -- this forces rebuilds of the library when the C library + * changes. The problem is that the pseudo binary may be + * a prebuilt, in which case it doesn't know about CHECKSUM, so it + * has to determine whether a given LD_PRELOAD contains libpseudo.so + * or libpseudoCHECKSUM.so, without prior knowledge... Fancy! + * + * We search for anything matching libpseudo*.so, where * is any + * sequence of non-spaces (including an empty string), with either + * the beginning of the string or a space in front of it, and either + * the end of the string or a space after it. + */ static char *libpseudo_name = "libpseudo.so"; +static char *libpseudo_pattern = "(=| )libpseudo[^ ]*\\.so($| )"; +static regex_t libpseudo_regex; +static int libpseudo_regex_compiled = 0; + +static int +libpseudo_regex_init(void) { + int rc; + + if (libpseudo_regex_compiled) + return 0; + rc = regcomp(&libpseudo_regex, libpseudo_pattern, REG_EXTENDED); + if (rc == 0) + libpseudo_regex_compiled = 1; + return rc; +} + +/* given a space-separated list of files, ala LD_PRELOAD, return that + * list without any variants of libpseudo*.so. + */ +static char * +without_libpseudo(char *list) { + regmatch_t pmatch[1]; + int counter = 0; + if (libpseudo_regex_init()) + return NULL; + + + if (regexec(&libpseudo_regex, list, 1, pmatch, 0)) { + return list; + } + list = strdup(list); + while (!regexec(&libpseudo_regex, list, 1, pmatch, 0)) { + char *start = list + pmatch[0].rm_so; + char *end = list + pmatch[0].rm_eo; + /* don't copy over the space or = */ + ++start; + memmove(start, end, strlen(end) + 1); + ++counter; + if (counter > 5) { + pseudo_diag("Found way too many libpseudo.so in environment, giving up.\n"); + return list; + } + } + return list; +} + +static char * +with_libpseudo(char *list) { + regmatch_t pmatch[1]; + if (libpseudo_regex_init()) + return NULL; + if (regexec(&libpseudo_regex, list, 1, pmatch, 0)) { + /* <%s %s\0> */ + size_t len = strlen(list) + 1 + strlen(libpseudo_name) + 1; + char *new = malloc(len); + if (new) + snprintf(new, len, "%s %s", list, + libpseudo_name); + return new; + } else { + return list; + } +} char *pseudo_version = PSEUDO_VERSION; @@ -382,25 +460,18 @@ pseudo_dropenv(char * const *environ) { j = 0; for (i = 0; environ[i]; ++i) { if (!memcmp(environ[i], "LD_PRELOAD=", 11)) { - char *s = environ[i] + 11; - char *p; - if (!strcmp(s, libpseudo_name)) { - /* drop it completely */ - continue; - } else if ((p = strstr(s, libpseudo_name)) != NULL) { - char *without = strdup(environ[i]); - if (!without) { - pseudo_diag("fatal: can't allocate new environment variable.\n"); - return 0; - } - p = strstr(without, libpseudo_name); - /* strip out that hunk */ - memmove(p, p + strlen(libpseudo_name), - strlen(p) - strlen(libpseudo_name) + 1); - new_environ[j++] = without; + char *new_val = without_libpseudo(environ[i]); + if (!new_val) { + pseudo_diag("fatal: can't allocate new environment variable.\n"); + return 0; } else { - /* leave it alone */ - new_environ[j++] = environ[i]; + /* don't keep an empty value */ + if (strcmp(new_val, "LD_PRELOAD=")) { + new_environ[j++] = new_val; + pseudo_diag("LD_PRELOAD: <%s>\n", new_environ[j - 1]); + } else { + pseudo_diag("dropping empty LD_PRELOAD\n"); + } } } else { new_environ[j++] = environ[i]; @@ -446,17 +517,14 @@ pseudo_setupenv(char * const *environ, char *opts) { j = 0; for (i = 0; environ[i]; ++i) { if (!memcmp(environ[i], "LD_PRELOAD=", 11)) { - if (!strstr(environ[i], libpseudo_name)) { - len = strlen(environ[i]) + strlen(libpseudo_name) + 2; - newenv = malloc(len); - if (!newenv) { - pseudo_diag("fatal: can't allocate new environment variable.\n"); - } - snprintf(newenv, len, "%s %s", environ[i], libpseudo_name); - new_environ[j++] = newenv; - } else { - new_environ[j++] = environ[i]; + pseudo_diag("modifying existing LD_PRELOAD\n"); + newenv = with_libpseudo(environ[i]); + pseudo_diag("LD_PRELOAD: <%s>\n", newenv); + if (!newenv) { + pseudo_diag("fatal: can't allocate new environment variable.\n"); + return NULL; } + new_environ[j++] = newenv; } else if (!memcmp(environ[i], "LD_LIBRARY_PATH=", 16)) { if (!strstr(environ[i], PSEUDO_PREFIX)) { char *e1, *e2; @@ -491,12 +559,12 @@ pseudo_setupenv(char * const *environ, char *opts) { new_environ[j++] = newenv; } if (!found_preload) { - len = 11 + strlen(libpseudo_name) + 1; - newenv = malloc(len); + pseudo_diag("creating new LD_PRELOAD\n"); + newenv = "LD_PRELOAD=libpseudo.so"; + pseudo_diag("newenv: %s\n", newenv); if (!newenv) { pseudo_diag("fatal: can't allocate new environment variable.\n"); } - snprintf(newenv, len, "LD_PRELOAD=%s", libpseudo_name); new_environ[j++] = newenv; } if (!found_debug && max_debug_level > 0) { |