From 363838cb3f8d2cda86ae46d8decddcbec3b7cb1c Mon Sep 17 00:00:00 2001 From: An-Cheng Huang Date: Thu, 12 May 2011 22:47:30 +0800 Subject: fix for bug 6771 * reimplement process management to fix breakage caused by commit 792d6aa0dd0ecfd45c9b5ab57c6c0cb71a9b8da6. --- src/cli_cstore.h | 3 +- src/cli_new.c | 327 ++++++++++++++++++++++++++++++-------------------- src/commit2.cpp | 8 +- src/cstore/cstore.cpp | 2 +- src/exe_action.c | 2 +- 5 files changed, 201 insertions(+), 141 deletions(-) (limited to 'src') diff --git a/src/cli_cstore.h b/src/cli_cstore.h index c62f2e0..51ca502 100644 --- a/src/cli_cstore.h +++ b/src/cli_cstore.h @@ -132,8 +132,7 @@ int get_shell_command_output(const char *cmd, char *buf, unsigned int buf_size); int parse_def(vtw_def *defp, const char *path, boolean type_only); boolean validate_value(const vtw_def *def, char *value); -boolean execute_list(vtw_node *cur, const vtw_def *def, const char *outbuf, - boolean format); +boolean execute_list(vtw_node *cur, const vtw_def *def, const char *outbuf); const char *type_to_name(vtw_type_e type); int initialize_output(const char *op); void bye(const char *msg, ...) __attribute__((format(printf, 1, 2), noreturn)); diff --git a/src/cli_new.c b/src/cli_new.c index 30a028b..be1264a 100644 --- a/src/cli_new.c +++ b/src/cli_new.c @@ -428,15 +428,17 @@ get_config_lock() returns TRUE if every excution returns NULL */ boolean -execute_list(vtw_node *cur, const vtw_def *def, const char *prepend_msg, - boolean format) +execute_list(vtw_node *cur, const vtw_def *def, const char *prepend_msg) { boolean ret; int status; set_in_exec(TRUE); status = char2val(def, get_at_string(), &validate_value_val); if (status) return FALSE; - ret = check_syn(cur,prepend_msg,format); + + // XXX emulate original impl for "error" location + ret = check_syn(cur, prepend_msg, + (getenv("VYATTA_OUTPUT_ERROR_LOCATION") != NULL)); free_val(&validate_value_val); set_in_exec(FALSE); return ret; @@ -2101,149 +2103,208 @@ restore_output() return 0; } -/* system_out: - * call system() with output re-enabled. - * output is again redirected before returning from here. - * note: this function may be used outside of actual CLI operations, so output - * may not have been redirected. check out_stream for such cases. - */ - -int -old_system_out(const char *command) -{ - int ret = -1; - if (out_stream && restore_output() == -1) { - return -1; - } - - ret = system(command); - if (out_stream && redirect_output() == -1) { - return -1; - } - - // fprintf(out_stream,"old system out: %d, for cmd: %s\n",ret,command); - return ret; -} - int -system_out(const char *cmd, const char *prepend_msg, boolean format) +system_out(const char *cmd, const char *prepend_msg, boolean eloc) { - // fprintf(out_stream,"system out\n"); - if (prepend_msg == NULL) { - return old_system_out(cmd); - } - if (cmd == NULL) { - return -1; - } + int pfd[2]; + int ret; + pid_t cpid; - int cp[2]; // Child to parent pipe - if( pipe(cp) < 0) { + if (!cmd || (ret = pipe(pfd)) != 0) { return -1; } - pid_t pid = fork(); - if (pid == 0) { - //child - close(cp[0]); - close(STDIN_FILENO); // Close current stdout./ - dup2(cp[1],STDOUT_FILENO); // Make stdout go to write end of pipe. - dup2(cp[1],STDERR_FILENO); // Make stderr go to write end of pipe. - close(cp[1]); - int ret = 0; - // fprintf(out_stream,"executing: %s\n",cmd); - if (execl("/bin/sh","sh","-c",cmd,NULL) == -1) { - ret = errno; + /* note that the process management mechanism here is a new implementation. + * this fixes bug 6771, which was broken by the change introduced in + * commit 792d6aa0dd0ecfd45c9b5ab57c6c0cb71a9b8da6. + * + * basically, that commit changed the process management such that the + * commit process does not terminate if any child process is spawned in a + * certain way (more specifically, if its STDERR fd is not closed). + * + * saying that "STDERR *should* be closed and therefore this is not our + * fault" is not an acceptable solution since we use many debian packages + * "as-is", and expecting all child processes spawned by any present and + * future packages in our system to do that is not practical (nor is it + * feasible to expect us to keep finding and fixing such cases, which + * would most likely involve taking ownership of debian packages that we + * could have used as-is.) + * + * the new process management mechanism below does not have this problem. + */ + if ((cpid = fork())) { + int status; + int waited = 0; + int prepend = 1; + + if (cpid == -1) { + return -1; } - close(cp[1]); - exit(ret); - } - else { - //parent - char buf[8192]; - char last_char = '\0'; - memset(buf,'\0',8192); - close(cp[1]); - boolean first = TRUE; - boolean print = FALSE; - fd_set rfds; - struct timeval tv; - char errloc_buf[] = "_errloc_:"; - size_t errloc_len = strlen(errloc_buf); - - FD_ZERO(&rfds); - FD_SET(cp[0], &rfds); - tv.tv_sec = 1; - tv.tv_usec = 0; - - int flags = fcntl(cp[0], F_GETFL); - flags |= O_NONBLOCK; fcntl(cp[0], F_SETFL, flags); - - while (select(FD_SETSIZE, &rfds, NULL, NULL, &tv) != -1) { - int err = 0; - if ((err = read(cp[0], &buf, 8191)) > 0) { - - - print = TRUE; - if (first == TRUE) { - if (strncmp(buf,errloc_buf,errloc_len) == 0) { - if (format == FALSE) { - fprintf(out_stream,"%s",buf+errloc_len); - } - else { - fprintf(out_stream,"%s",buf); - } - } - else { - //currently set to format option for GUI client. - if (prepend_msg != NULL) { - if (format == FALSE) { - fprintf(out_stream,"[%s]\n%s",prepend_msg,buf); - } - else { - fprintf(out_stream,"%s[%s]\n%s",errloc_buf,prepend_msg,buf); - } - } - } - } - else { - if (strncmp(buf,errloc_buf,errloc_len) == 0 && format == FALSE) { - fprintf(out_stream,"%s",buf+errloc_len); - } - else { - fprintf(out_stream,"%s",buf); - } - } + close(pfd[1]); + while (1) { + int sret; + fd_set readfds; + struct timeval timeout; + FD_ZERO(&readfds); + FD_SET(pfd[0], &readfds); + timeout.tv_sec = 0; + timeout.tv_usec = 100000; + sret = select(pfd[0] + 1, &readfds, NULL, NULL, &timeout); + if (sret == 1) { + /* ready for read */ + char buf[128]; + char *out = buf; + ssize_t count = read(pfd[0], buf, 128); + if (count <= 0) { + /* eof or error */ + break; + } - first = FALSE; - last_char = buf[strlen(buf)-2]; - memset(buf,'\0',8192); - } - else if (err == -1 && errno == EAGAIN) { - //try again - } - else { - break; - } - FD_ZERO(&rfds); - FD_SET(cp[0], &rfds); - tv.tv_sec = 1; - tv.tv_usec = 0; + /* XXX XXX XXX BEGIN emulating original "error" location handling */ + + /* the following code segment is the "logic" for handling "error" + * location in the original impl. (note that this code is preserved + * here for demonstration purpose. this is not "commented-out" + * code.) + */ + /*** + if (first == TRUE) { + if (strncmp(buf,errloc_buf,errloc_len) == 0) { + if (format == FALSE) { + fprintf(out_stream,"%s",buf+errloc_len); + } + else { + fprintf(out_stream,"%s",buf); + } + } else { + //currently set to format option for GUI client. + if (prepend_msg != NULL) { + if (format == FALSE) { + fprintf(out_stream,"[%s]\n%s",prepend_msg,buf); + } else { + fprintf(out_stream,"%s[%s]\n%s",errloc_buf,prepend_msg,buf); + } + } + } + } else { + if (strncmp(buf,errloc_buf,errloc_len) == 0 && format == FALSE) { + fprintf(out_stream,"%s",buf+errloc_len); + } else { + fprintf(out_stream,"%s",buf); + } + } + ***/ + /* XXX analysis of above: + * the main issue is that this seems to indicate that the "error" + * location can actually be prepended in two different layers (the + * layer here and the actual command output). the "logic" above + * seems to be: + * (1) for first buffer read + * (A) if the lower layer has already prepended "errloc" string + * (a) if we DON'T want errloc string, then strip it from + * the lower-layer output. + * (b) if we DO want the string, let it pass through + * (B) if the lower layer did not prepend + * (a) if we DON'T want errloc, don't prepend it here + * (b) if we DO want the string, prepend it here + * (2) for any subsequent buffer reads + * (A) if lower layer prepended errloc AND we DON'T want errloc, + * strip it from output + * (B) otherwise (lower layer did not prepend OR + * we DO want errloc), let it pass through + * + * note that the handling of subsequent buffer reads makes no sense. + * the reads can start at any offsets, so if we actually need to + * strip out any errloc string at the start of any subsequent reads + * from the command output, then something is very broken here. + * + * secondly, assuming (2) is in fact not needed, the main issue + * in (1) is the fact that the errloc string can be prepended in two + * different layers, resulting in the "logic" seen above. if the + * eventual appearance (i.e., errloc or not) is completely determined + * in this layer here, then such a "design" choice is weird. + * + * given the resource availability, at the moment, the only feasible + * approach here is to emulate the original impl's behavior in terms + * of "errloc". + * + * another (unrelated) issue is that the original impl assumes the + * buffer reads do not contain any '\0' bytes since it uses + * fprintf() to output the buffer. A '\0' byte will cause the rest + * of the buffer to be truncated. the new impl does not have this + * problem. + * + * the logic below emulates the case (1) in the original impl and + * ignores case (2). if somehow case (2) is indeed necessary, we + * should really take a good look at the reason and fix the + * underlying problem. (heck, even (1) is fugly as hell, but + * right now it's simply not feasible to look into it.) + */ + if (prepend) { + prepend = 0; + + /* XXX follow original behavior */ +#define errloc_str "_errloc_:" +#define errloc_len 9 + if (count > errloc_len + && memcmp(buf, errloc_str, errloc_len) == 0) { + /* XXX lower-layer already prepended errloc, so strip it out if + * we don't want errloc. AND in such cases we don't want the + * prepend_msg either. (!?) + */ + out = (eloc ? buf : (buf + errloc_len)); + } else { + /* XXX lower-layer did not prepend errloc */ + if (eloc) { + /* XXX prepend errloc since we want it */ + fprintf(out_stream, "%s", errloc_str); + } + /* XXX and in such cases we DO want prepend_msg */ + if (prepend_msg) { + fprintf(out_stream, "[%s]\n", prepend_msg); + } + } +#undef errloc_str +#undef errloc_len + } - fflush(NULL); - } + /* XXX XXX XXX END emulating original "error" location handling */ - if (print == TRUE && last_char != '\n') { - fprintf(out_stream,"\n"); + if (fwrite(out, count, 1, out_stream) != 1) { + return -1; + } + } else if (sret == 0) { + /* timeout */ + if (waitpid(cpid, &status, WNOHANG) == cpid) { + /* child done */ + waited = 1; + break; + } + } else { + /* error (-1) */ + break; + } } - //now wait on child to kick the bucket - int status; - wait(&status); - close(cp[0]); - if (WIFEXITED(status)) { - return WEXITSTATUS(status); + if (!prepend) { + fprintf(out_stream, "\n"); + } + if (!waited) { + if (waitpid(cpid, &status, 0) != cpid) { + return -1; + } + } + return (WIFEXITED(status) ? WEXITSTATUS(status) : 1); + } else { + /* child process */ + close(pfd[0]); + if ((ret = dup2(pfd[1], STDOUT_FILENO) < 0) + || (ret = dup2(pfd[1], STDERR_FILENO)) < 0) { + exit(1); } - return 1; + char *eargs[] = { "sh", "-c", cmd, NULL }; + execv("/bin/sh", eargs); + return -1; /* should not get here */ } } diff --git a/src/commit2.cpp b/src/commit2.cpp index 45d53bc..be51069 100644 --- a/src/commit2.cpp +++ b/src/commit2.cpp @@ -639,13 +639,13 @@ process_func(GNode *node, gpointer data) if (g_old_print_output == TRUE) { status = execute_list(c->_def.actions[result->_action].vtw_list_head, - &c->_def, NULL, g_print_error_location_all); + &c->_def, NULL); } else { char *p = process_script_path(d->_path); status = execute_list(c->_def.actions[result->_action].vtw_list_head, - &c->_def, p, g_print_error_location_all); + &c->_def, p); free(p); } } else { @@ -1458,12 +1458,12 @@ validate_func(GNode *node, gpointer data) if (g_old_print_output == TRUE) { status = execute_list(c->_def.actions[result->_action].vtw_list_head, - &c->_def, NULL, g_print_error_location_all); + &c->_def, NULL); } else { char *p = process_script_path(d->_path); status = execute_list(c->_def.actions[result->_action].vtw_list_head, - &c->_def, p, g_print_error_location_all); + &c->_def, p); free(p); } unsetenv(ENV_DATA_PATH); diff --git a/src/cstore/cstore.cpp b/src/cstore/cstore.cpp index b549649..6e205ef 100644 --- a/src/cstore/cstore.cpp +++ b/src/cstore/cstore.cpp @@ -1898,7 +1898,7 @@ Cstore::executeTmplActions(char *at_str, const Cpath& path, var_ref_handle = (void *) this; // const_cast for legacy code bool ret = execute_list(const_cast(actions), def, - sdisp.c_str(), false); + sdisp.c_str()); var_ref_handle = NULL; return ret; } diff --git a/src/exe_action.c b/src/exe_action.c index 53d2be4..752a1d9 100644 --- a/src/exe_action.c +++ b/src/exe_action.c @@ -85,7 +85,7 @@ main(int argc, char** argv) //BROKEN--NEEDS TO BE FIX BELOW FOR DPATH AND CPATH common_set_context(path,path); - status = execute_list(def.actions[act].vtw_list_head,&def,NULL,FALSE); + status = execute_list(def.actions[act].vtw_list_head, &def, NULL); if (status == FALSE) { printf("command failed! status: %d\n", status); } -- cgit v1.2.3