/* ** OSSP l2 - Flexible Logging ** Copyright (c) 2001-2003 Cable & Wireless Deutschland GmbH ** Copyright (c) 2001-2003 The OSSP Project (http://www.ossp.org/) ** Copyright (c) 2001-2003 Ralf S. Engelschall ** ** This file is part of OSSP l2, a flexible logging library which ** can be found at http://www.ossp.org/pkg/lib/l2/. ** ** Permission to use, copy, modify, and distribute this software for ** any purpose with or without fee is hereby granted, provided that ** the above copyright notice and this permission notice appear in all ** copies. ** ** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED ** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF ** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. ** IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR ** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF ** USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, ** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ** OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF ** SUCH DAMAGE. ** ** l2_ch_file.c: file channel implementation */ #include "l2.h" #include #include #include /* declare private channel configuration */ typedef struct { int fd; char *path; int append; int trunc; int perm; int jitter; } l2_ch_file_t; /* create channel */ static l2_result_t hook_create(l2_context_t *ctx, l2_channel_t *ch) { l2_ch_file_t *cfg; /* allocate private channel configuration */ if ((cfg = (l2_ch_file_t *)malloc(sizeof(l2_ch_file_t))) == NULL) return L2_ERR_ARG; /* initialize configuration with reasonable defaults */ cfg->fd = -1; cfg->path = NULL; cfg->append = -1; cfg->trunc = -1; cfg->perm = (S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH); cfg->jitter = 0; /* link private channel configuration into channel context */ ctx->vp = cfg; return L2_OK; } /* configure channel */ static l2_result_t hook_configure(l2_context_t *ctx, l2_channel_t *ch, const char *fmt, va_list ap) { l2_ch_file_t *cfg = (l2_ch_file_t *)ctx->vp; l2_param_t pa[6]; l2_result_t rv; l2_env_t *env; /* feed and call generic parameter parsing engine */ L2_PARAM_SET(pa[0], path, STR, &cfg->path); L2_PARAM_SET(pa[1], append, INT, &cfg->append); L2_PARAM_SET(pa[2], trunc, INT, &cfg->trunc); L2_PARAM_SET(pa[3], perm, INT, &cfg->perm); L2_PARAM_SET(pa[4], jitter, INT, &cfg->jitter); L2_PARAM_END(pa[5]); l2_channel_env(ch, &env); rv = l2_util_setparams(env, pa, fmt, ap); return rv; } /* open channel */ static l2_result_t hook_open(l2_context_t *ctx, l2_channel_t *ch) { l2_ch_file_t *cfg = (l2_ch_file_t *)ctx->vp; int mode; mode_t mask; /* "append" backward compatibility; only cfg->trunc is used in the code * make sure append/trunc either both use defaults, both are set different, or only one is set * * truth table for user input, append, trunc => resulting trunc * -----------------+------+------+------------------ * -1 -1 0 (default) * trunc=0 -1 0 0 * trunc=1 -1 1 1 * append=0 0 -1 1 * append=0, trunc=0 0 0 ERROR * append=0, trunc=1 0 1 1 * append=1 1 -1 0 * append=1, trunc=0 1 0 0 * append=1, trunc=1 1 1 ERROR */ if (cfg->append >= 1) cfg->append = 1; /* reduce to -1 (undef), 0 (no), 1 (yes) */ if (cfg->trunc >= 1) cfg->trunc = 1; /* reduce to -1 (undef), 0 (no), 1 (yes) */ if ( cfg->append != -1 && cfg->trunc != -1 && cfg->append == cfg->trunc) /* collision */ return L2_ERR_USE; if ( cfg->trunc == -1) cfg->trunc = (1 - cfg->append) & 1; /* reduce jitter to 0 (no) or 1 (yes) */ if (cfg->jitter <= 0) cfg->jitter = 0; if (cfg->jitter >= 1) cfg->jitter = 1; /* make sure a path was set */ if (cfg->path == NULL) return L2_ERR_USE; /* open channel file */ mode = O_WRONLY|O_CREAT; if (cfg->trunc == 1) mode |= O_TRUNC; else mode |= O_APPEND; mask = umask(0); cfg->fd = open(cfg->path, mode, cfg->perm); umask(mask); if (cfg->fd == -1) return L2_ERR_SYS; /* close channel file if jittering, we just wanted to see a successful open and truncate if required */ if (cfg->jitter == 1) { close(cfg->fd); cfg->fd = -1; } return L2_OK; } /* write to channel */ static l2_result_t hook_write(l2_context_t *ctx, l2_channel_t *ch, l2_level_t level, const char *buf, size_t buf_size) { l2_ch_file_t *cfg = (l2_ch_file_t *)ctx->vp; l2_result_t rc = L2_OK; mode_t mask; /* handle the impossible; close any lingering file if jittering */ if (cfg->fd != -1 && cfg->jitter == 1) { close(cfg->fd); cfg->fd = -1; } /* open channel file if jittering */ if (cfg->fd == -1 && cfg->jitter == 1) { mask = umask(0); cfg->fd = open(cfg->path, O_WRONLY|O_CREAT|O_APPEND, cfg->perm); umask(mask); } if (cfg->fd == -1) return L2_ERR_SYS; /* write message to channel file */ if (write(cfg->fd, buf, buf_size) == -1) rc = L2_ERR_SYS; /* close channel file if jittering */ if (cfg->jitter == 1) { close(cfg->fd); cfg->fd = -1; } return rc; } /* close channel */ static l2_result_t hook_close(l2_context_t *ctx, l2_channel_t *ch) { l2_ch_file_t *cfg = (l2_ch_file_t *)ctx->vp; /* close channel file */ close(cfg->fd); cfg->fd = -1; return L2_OK; } /* destroy channel */ static l2_result_t hook_destroy(l2_context_t *ctx, l2_channel_t *ch) { l2_ch_file_t *cfg = (l2_ch_file_t *)ctx->vp; /* destroy channel configuration */ if (cfg->path != NULL) free(cfg->path); free(cfg); return L2_OK; } /* exported channel handler structure */ l2_handler_t l2_handler_file = { "file", L2_CHANNEL_OUTPUT, hook_create, hook_configure, hook_open, hook_write, NULL, hook_close, hook_destroy };